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Post by 90GTVert on Dec 6, 2023 9:10:52 GMT -5
I just pulled the plug and that confirmed my suspicion. I can’t really see in the plug hole because of the frame support so exactly how big the hole is will remain a mystery till I get the engine out. ![](https://uploads.tapatalk-cdn.com/20231206/714a4b6b69f7f317cadc72e0dc759ad7.jpg)
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Post by ryan_ott on Dec 6, 2023 15:18:56 GMT -5
Guess you know the EGT is accurate now.
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Post by 90GTVert on Dec 6, 2023 15:49:45 GMT -5
Guess you know the EGT is accurate now. Everyone should test their EGT this way... just to be safe.
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Post by aeroxbud on Dec 6, 2023 16:14:28 GMT -5
I blame the carb. Did it come with a warranty?
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Post by 90GTVert on Dec 6, 2023 18:13:01 GMT -5
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Post by oldgeek on Dec 6, 2023 18:32:36 GMT -5
................................................ It actually feels like it has a surge of power if I back off slow from WOT… but it’s more aggressive than anything I recall with typical tuning experiences. I wonder if that is a PWK thing because I experience that a lot too? How does the bottom of the piston look?
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Post by 90GTVert on Dec 6, 2023 18:40:25 GMT -5
![](https://uploads.tapatalk-cdn.com/20231206/c7526c039c7f0d179a20c4acd15a531d.jpg) Pretty much how it always looks, though there may be some very minor deposits. After so many years of AC and not so great LC, the underside of the RC’s pistons always look pretty good to me.
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tysta
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Post by tysta on Dec 8, 2023 21:17:33 GMT -5
................................................ It actually feels like it has a surge of power if I back off slow from WOT… but it’s more aggressive than anything I recall with typical tuning experiences. I wonder if that is a PWK thing because I experience that a lot too? How does the bottom of the piston look? Iam not understanding something did you just said you have the aside from the timing recommend by mvt an additional 3 degrees?!
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Post by 90GTVert on Dec 9, 2023 7:13:09 GMT -5
Iam not understanding something did you just said you have the aside from the timing recommend by mvt an additional 3 degrees?! - It was originally set 0.35mm BTDC as MVT instructs for longer stroke. It was like that since day 1 with the RC-1. - When I installed the PWK, EGT was very hot unless I ran huge jets or took the main jet out totally. Nothing that I changed with the carb would change that. - I advanced the timing 3 degrees to 0.62mm BTDC, thinking that perhaps it needed more timing with the big carb because high EGT can be an indication of insufficient ignition advance and Malossi's standard ignition curve has roughly 3 degrees more advance than the MVT around peak power. The only problem is, the MVT has more advance at low RPM, so now it's very high at low revs. ~45 degrees max advance where the MHR is only peaking around 35 max. Graph below shows MVT standard vs MVT 3 degrees advanced vs MHR standard. - That worked. Suddenly my EGTs were pretty much where they have been with the VHST when dragy results were good and I was using much more standard sized jetting. - I dialed in the CVT so it would stay much closer to peak power and at that point it started getting hot EGTs by the end of 1/8 mile runs again. My intention was to see if it went away with larger jets, but it ate a piston when I put a larger jet in. It was working well up to 1/4 throttle for sure, with good safe EGT, but I think above that when the engine was a bit more efficient the high advance may have been too much for it. It was just strange to see EGT jump with CVT tuning. I've never experienced a major change like that from CVT tuning with anything else. ![](https://i.postimg.cc/jj7K5vH6/MVT-MHR-Adv.png) My thoughts at this point are that when it goes back together perhaps I should go back to the timing that it was at and just assume that it's putting a lot of heat into the pipe and not necessarily roasting in the cylinder. I thought about the MVT EPROM to have a different curve, but it doesn't look like that would solve anything. ![](https://www.49ccscoot.com/pics/1/MVTCOMBINED.jpg)
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tysta
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Post by tysta on Dec 11, 2023 1:15:14 GMT -5
Ok sorry to say that was the mistake. The ignition is too advanced Our pump fuel even the 93 isn't that great, also sometimes the quantity of ethanol on the fuel can cause this problem. But wasn'tthe case here I remember mentioning the ignition before, those mvt are so stupid with the dual spark. The piston was getting too hot , and yes you won't see on your coolant temp sensor. The reason for that it's because it's very slow to respond to temperature changes. You should re time it to about 0.31 and then check with the gun the advance at 14k rpm Also make sure your float hight on the carb is set best possible also make sure the carb gets enough flow. The reason why it was making you mess with the needles in carb was too much advance till 9k You should be able to run the stock needle just using different jets. After you have the ignition set like I was saying you should se a more normal jetting if not if possible your fuel is foaming inside the carb if that happens let me know I might be able to help. Now your cylinder have small damages I might be able to remove the melted piston and bring the cross hatch back. You just need to send me the cylinder with one piston for reference. Iam not understanding something did you just said you have the aside from the timing recommend by mvt an additional 3 degrees?! - It was originally set 0.35mm BTDC as MVT instructs for longer stroke. It was like that since day 1 with the RC-1. - When I installed the PWK, EGT was very hot unless I ran huge jets or took the main jet out totally. Nothing that I changed with the carb would change that. - I advanced the timing 3 degrees to 0.62mm BTDC, thinking that perhaps it needed more timing with the big carb because high EGT can be an indication of insufficient ignition advance and Malossi's standard ignition curve has roughly 3 degrees more advance than the MVT around peak power. The only problem is, the MVT has more advance at low RPM, so now it's very high at low revs. ~45 degrees max advance where the MHR is only peaking around 35 max. Graph below shows MVT standard vs MVT 3 degrees advanced vs MHR standard. - That worked. Suddenly my EGTs were pretty much where they have been with the VHST when dragy results were good and I was using much more standard sized jetting. - I dialed in the CVT so it would stay much closer to peak power and at that point it started getting hot EGTs by the end of 1/8 mile runs again. My intention was to see if it went away with larger jets, but it ate a piston when I put a larger jet in. It was working well up to 1/4 throttle for sure, with good safe EGT, but I think above that when the engine was a bit more efficient the high advance may have been too much for it. It was just strange to see EGT jump with CVT tuning. I've never experienced a major change like that from CVT tuning with anything else. ![](https://i.postimg.cc/jj7K5vH6/MVT-MHR-Adv.png) My thoughts at this point are that when it goes back together perhaps I should go back to the timing that it was at and just assume that it's putting a lot of heat into the pipe and not necessarily roasting in the cylinder. I thought about the MVT EPROM to have a different curve, but it doesn't look like that would solve anything. ![](https://www.49ccscoot.com/pics/1/MVTCOMBINED.jpg)
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Post by 90GTVert on Dec 11, 2023 7:42:17 GMT -5
Ok sorry to say that was the mistake. The ignition is too advanced Our pump fuel even the 93 isn't that great, also sometimes the quantity of ethanol on the fuel can cause this problem. But wasn'tthe case here I remember mentioning the ignition before, those mvt are so stupid with the dual spark. The problem that I've had is that some people have told me the MVT is not good. No one has ever said exactly why, so I took it as preference or just something they'd heard. This is how many comments about performance stuff goes and it's a lot of the reason that I share the things that I do. Sadly, I had to find out the hard way on my own that perhaps the curve is not great. I've suspected that it's a lot of advance down low (well, I know it's a lot because I checked), but it has worked very well for me till now to my knowledge. Now I'm wondering if I didn't struggle and never get the Lectron in tune on my 86cc with an MVT partially because of the amount of advance at lower RPM (part throttle). I still don't like that setup, but the advance likely didn't do me any favors with part throttle piston destruction there either. John sent me a link to this post from a pro about ignition timing : www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1131221299#post1131221299"the most useable midrange advance is 30 to 32* and this can be a straight line from around 2000 rpm to the point that the pipe starts to be effective and power is rising sharply per rpm step . This much static can only be used ( on petrol ) as long as the engine is not run for any extended period in that area - even warming up under load at part throttle. The next hard and fast rule is that if the compression is optimized for the fuel then its all but guaranteed you will need 15* advance at peak power. Thus you can draw a straight line from the 30* turnover point to that rpm. How much retard after peak power depends upon how much overev is needed. Then a flat line prevents excess egt rise that would need richer jetting to cool/ not make power. The straight line retard can be bent upward into a convex form by looking at the TubMax graph shape and pushing your luck with detonation
But the logic of using alot of advance to " get the pipe into resonance quicker " seems counterintuitive to me. The less advance , the hotter the pipe becomes , quicker . And if you have a port timing/pipe TL pairing that creates superposition within the powerband - the hotter the pipe , the quicker you get into that area. Sure , pushing the advance gives great throttle response , but Hp wise you are fighting excess compression losses BTDC as the piston is pushing against static compression as well as the quickly rising combustion pressure , thus slowing down the piston speed driven by only by crank inertia."I've always assumed that the high advance below pipe RPM was the reason for both setups with the MVT being very responsive and looked at it as a good thing... an advantage over what I see from other curves like Malossi's. The above makes me think what I've been coming to on my own is true. There's quite a bit too much advance in MVT's curves down low. It seems to work well enough in some cases, at least if the part throttle is pretty rich, but if you go for a leaner part throttle tune or try to advance the timing it may bite you. Makes me wonder if MVT uses this to make their ignitions feel even stronger or if they actually believe this is a good curve. Seems like other ignitions are much closer to what the above post specifies at lower RPM. I'd like to change the curve and stick with the MVT for charging because I like having something that I don't worry about on any length of ride due to battery power, but I'm not exactly sure how to get there yet. Most fully programmable CDIs are pretty expensive. I've wanted an MSD 4217 for years, but it's $400+ for just a CDI. Other brands make them as well, but none of them are cheap. If I knew for sure I could make it work, I'd probably go for one. I'm afraid the MVT may not work with them, and even worse, may damage a CDI. The MVT doesn't seem to have a pickup/trigger wire. I'm not sure if it uses the exciter signal as a pickup or how it works. If it is using the exciter signal as a trigger, then I would think that may be enough to fry a CDI that's just looking for a low voltage signal for the pickup. Not cool when you put out hundreds of dollars for a CDI. I've got an AliExpress DC CDI that is supposed to allow full control of the curve up to 16,000RPM. I bought it for a 4T years ago and never got around to trying it. It was still $70-80 IIRC, but at least it's not hundreds if I fry it. I may try to see if that works at some point, unless someone knows of an MVT compatible CDI that doesn't have the huge lower RPM advance like the standard and EPROM from MVT. You should re time it to about 0.31 and then check with the gun the advance at 14k rpm Can't do it. I've tried I think 4 different lights and none can keep up to measure it full song. The closest still quits before that. Don't ask me why I managed it once on a Minarelli MVT and with the Piaggio MVT I can't get there. The good news is, the curve that I recorded on the Minarelli seems to match what the Piaggio MVT I'm using now is doing up as far as I can see with the light working. That doesn't tell me for sure what it's doing at 14k, but it's as close as I can get. Also make sure your float hight on the carb is set best possible also make sure the carb gets enough flow. I had the same thought on the last set of runs... but it died before I got there. Prior to that, it was high enough that I've had it leak when leaned over on the stand a couple of times and I'll see some evidence of dribble at times. I could run it with huge jets and it would keep acting rich all the way through a run. That doesn't mean something didn't mess up toward the end, but it appeared as if once I put the CVT tune in the RPM sweet spot it suddenly got hot. The reason why it was making you mess with the needles in carb was too much advance till 9k You should be able to run the stock needle just using different jets. After you have the ignition set like I was saying you should se a more normal jetting if not if possible your fuel is foaming inside the carb if that happens let me know I might be able to help. I had the same thought on the needle tuning as well and what John linked me to supports that idea as well. Setting it to 0.31mm BTDC would be essentially the same as where I started. I started out on 0.35mm BTDC and that's when it was giving me 1400 degree EGT readings unless I used huge jets or no main jet at all. 0.04mm is basically a half a degree different from where I was. I've ran 0.35mm since the day I put the RC-1 together and never changed it till the big carb gave me high WOT EGTs. Now your cylinder have small damages I might be able to remove the melted piston and bring the cross hatch back. You just need to send me the cylinder with one piston for reference. I've got some muriatic acid that I'm gonna try to see how much of the marking is transfer from the piston and how much is actual damage to the cylinder. Gonna try to be sparing with it on a Q-tip and hope I don't get any in a port. Hoping I'll get lucky and that and some Scotch Brite will make it good enough and I can measure and see if a C piston is still what I need or not. I've got ball hones too, but I see some people say a couple of quick passes are good and some say don't touch a plated cylinder with a hone and crosshatch is not so necessary on plated aluminum as it is on iron jugs so I was just gonna go with some hand work where necessary. Thank you for the offer!
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tysta
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Post by tysta on Dec 11, 2023 8:12:06 GMT -5
Well i told you before the curve isn't good the dual spark isn't good for performance either. You can even notice at idle the engine runs so much better with a proper ignition. Ok sorry to say that was the mistake. The ignition is too advanced Our pump fuel even the 93 isn't that great, also sometimes the quantity of ethanol on the fuel can cause this problem. But wasn'tthe case here I remember mentioning the ignition before, those mvt are so stupid with the dual spark. The problem that I've had is that some people have told me the MVT is not good. No one has ever said exactly why, so I took it as preference or just something they'd heard. This is how many comments about performance stuff goes and it's a lot of the reason that I share the things that I do. Sadly, I had to find out the hard way on my own that perhaps the curve is not great. I've suspected that it's a lot of advance down low (well, I know it's a lot because I checked), but it has worked very well for me till now to my knowledge. Now I'm wondering if I didn't struggle and never get the Lectron in tune on my 86cc with an MVT partially because of the amount of advance at lower RPM (part throttle). I still don't like that setup, but the advance likely didn't do me any favors with part throttle piston destruction there either. John sent me a link to this post from a pro about ignition timing : www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1131221299#post1131221299"the most useable midrange advance is 30 to 32* and this can be a straight line from around 2000 rpm to the point that the pipe starts to be effective and power is rising sharply per rpm step . This much static can only be used ( on petrol ) as long as the engine is not run for any extended period in that area - even warming up under load at part throttle. The next hard and fast rule is that if the compression is optimized for the fuel then its all but guaranteed you will need 15* advance at peak power. Thus you can draw a straight line from the 30* turnover point to that rpm. How much retard after peak power depends upon how much overev is needed. Then a flat line prevents excess egt rise that would need richer jetting to cool/ not make power. The straight line retard can be bent upward into a convex form by looking at the TubMax graph shape and pushing your luck with detonation
But the logic of using alot of advance to " get the pipe into resonance quicker " seems counterintuitive to me. The less advance , the hotter the pipe becomes , quicker . And if you have a port timing/pipe TL pairing that creates superposition within the powerband - the hotter the pipe , the quicker you get into that area. Sure , pushing the advance gives great throttle response , but Hp wise you are fighting excess compression losses BTDC as the piston is pushing against static compression as well as the quickly rising combustion pressure , thus slowing down the piston speed driven by only by crank inertia."I've always assumed that the high advance below pipe RPM was the reason for both setups with the MVT being very responsive and looked at it as a good thing... an advantage over what I see from other curves like Malossi's. The above makes me think what I've been coming to on my own is true. There's quite a bit too much advance in MVT's curves down low. It seems to work well enough in some cases, at least if the part throttle is pretty rich, but if you go for a leaner part throttle tune or try to advance the timing it may bite you. Makes me wonder if MVT uses this to make their ignitions feel even stronger or if they actually believe this is a good curve. Seems like other ignitions are much closer to what the above post specifies at lower RPM. I'd like to change the curve and stick with the MVT for charging because I like having something that I don't worry about on any length of ride due to battery power, but I'm not exactly sure how to get there yet. Most fully programmable CDIs are pretty expensive. I've wanted an MSD 4217 for years, but it's $400+ for just a CDI. Other brands make them as well, but none of them are cheap. If I knew for sure I could make it work, I'd probably go for one. I'm afraid the MVT may not work with them, and even worse, may damage a CDI. The MVT doesn't seem to have a pickup/trigger wire. I'm not sure if it uses the exciter signal as a pickup or how it works. If it is using the exciter signal as a trigger, then I would think that may be enough to fry a CDI that's just looking for a low voltage signal for the pickup. Not cool when you put out hundreds of dollars for a CDI. I've got an AliExpress DC CDI that is supposed to allow full control of the curve up to 16,000RPM. I bought it for a 4T years ago and never got around to trying it. It was still $70-80 IIRC, but at least it's not hundreds if I fry it. I may try to see if that works at some point, unless someone knows of an MVT compatible CDI that doesn't have the huge lower RPM advance like the standard and EPROM from MVT. You should re time it to about 0.31 and then check with the gun the advance at 14k rpm Can't do it. I've tried I think 4 different lights and none can keep up to measure it full song. The closest still quits before that. Don't ask me why I managed it once on a Minarelli MVT and with the Piaggio MVT I can't get there. The good news is, the curve that I recorded on the Minarelli seems to match what the Piaggio MVT I'm using now is doing up as far as I can see with the light working. That doesn't tell me for sure what it's doing at 14k, but it's as close as I can get. Also make sure your float hight on the carb is set best possible also make sure the carb gets enough flow. I had the same thought on the last set of runs... but it died before I got there. Prior to that, it was high enough that I've had it leak when leaned over on the stand a couple of times and I'll see some evidence of dribble at times. I could run it with huge jets and it would keep acting rich all the way through a run. That doesn't mean something didn't mess up toward the end, but it appeared as if once I put the CVT tune in the RPM sweet spot it suddenly got hot. The reason why it was making you mess with the needles in carb was too much advance till 9k You should be able to run the stock needle just using different jets. After you have the ignition set like I was saying you should se a more normal jetting if not if possible your fuel is foaming inside the carb if that happens let me know I might be able to help. I had the same thought on the needle tuning as well and what John linked me to supports that idea as well. Setting it to 0.31mm BTDC would be essentially the same as where I started. I started out on 0.35mm BTDC and that's when it was giving me 1400 degree EGT readings unless I used huge jets or no main jet at all. 0.04mm is basically a half a degree different from where I was. I've ran 0.35mm since the day I put the RC-1 together and never changed it till the big carb gave me high WOT EGTs. Now your cylinder have small damages I might be able to remove the melted piston and bring the cross hatch back. You just need to send me the cylinder with one piston for reference. I've got some muriatic acid that I'm gonna try to see how much of the marking is transfer from the piston and how much is actual damage to the cylinder. Gonna try to be sparing with it on a Q-tip and hope I don't get any in a port. Hoping I'll get lucky and that and some Scotch Brite will make it good enough and I can measure and see if a C piston is still what I need or not. I've got ball hones too, but I see some people say a couple of quick passes are good and some say don't touch a plated cylinder with a hone and crosshatch is not so necessary on plated aluminum as it is on iron jugs so I was just gonna go with some hand work where necessary. Thank you for the offer!
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tysta
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Post by tysta on Dec 11, 2023 8:28:40 GMT -5
Well hpi have a fully programmable cdi you can try that. Yap that article is right exactly what iam saying 2t engines majority of them start to come alive around 8 to 9k its were you start retard timing Advance at lower rpm will work great any were from 30 to 35 degrees on 2t engines But the trick isn't to set it using the distance method but using a degree wheel and a dial indicator at same time. First you will need to find the true top dead center and from there then you can set the timing. It's mandatory to find true top dead center I have a video about it I can share it if needed. Lectrons are a waste of money all top guy aren't using that attempt of a copy of the yoshimura carbs. ( yes because they attempt and failed) lol I wouldn't use the muriatic acid because if you have a tiny pore on the plating it will eat the aluminum on the back of it. And the person who told you nicasil plating doesn't need cross hatch shouldn't come near any engine. Let me know if you need help. Good luck Well i told you before the curve isn't good the dual spark isn't good for performance either. You can even notice at idle the engine runs so much better with a proper ignition. The problem that I've had is that some people have told me the MVT is not good. No one has ever said exactly why, so I took it as preference or just something they'd heard. This is how many comments about performance stuff goes and it's a lot of the reason that I share the things that I do. Sadly, I had to find out the hard way on my own that perhaps the curve is not great. I've suspected that it's a lot of advance down low (well, I know it's a lot because I checked), but it has worked very well for me till now to my knowledge. Now I'm wondering if I didn't struggle and never get the Lectron in tune on my 86cc with an MVT partially because of the amount of advance at lower RPM (part throttle). I still don't like that setup, but the advance likely didn't do me any favors with part throttle piston destruction there either. John sent me a link to this post from a pro about ignition timing : www.kiwibiker.co.nz/forums/showthread.php/86554-ESE-s-works-engine-tuner?p=1131221299#post1131221299"the most useable midrange advance is 30 to 32* and this can be a straight line from around 2000 rpm to the point that the pipe starts to be effective and power is rising sharply per rpm step . This much static can only be used ( on petrol ) as long as the engine is not run for any extended period in that area - even warming up under load at part throttle. The next hard and fast rule is that if the compression is optimized for the fuel then its all but guaranteed you will need 15* advance at peak power. Thus you can draw a straight line from the 30* turnover point to that rpm. How much retard after peak power depends upon how much overev is needed. Then a flat line prevents excess egt rise that would need richer jetting to cool/ not make power. The straight line retard can be bent upward into a convex form by looking at the TubMax graph shape and pushing your luck with detonation
But the logic of using alot of advance to " get the pipe into resonance quicker " seems counterintuitive to me. The less advance , the hotter the pipe becomes , quicker . And if you have a port timing/pipe TL pairing that creates superposition within the powerband - the hotter the pipe , the quicker you get into that area. Sure , pushing the advance gives great throttle response , but Hp wise you are fighting excess compression losses BTDC as the piston is pushing against static compression as well as the quickly rising combustion pressure , thus slowing down the piston speed driven by only by crank inertia."I've always assumed that the high advance below pipe RPM was the reason for both setups with the MVT being very responsive and looked at it as a good thing... an advantage over what I see from other curves like Malossi's. The above makes me think what I've been coming to on my own is true. There's quite a bit too much advance in MVT's curves down low. It seems to work well enough in some cases, at least if the part throttle is pretty rich, but if you go for a leaner part throttle tune or try to advance the timing it may bite you. Makes me wonder if MVT uses this to make their ignitions feel even stronger or if they actually believe this is a good curve. Seems like other ignitions are much closer to what the above post specifies at lower RPM. I'd like to change the curve and stick with the MVT for charging because I like having something that I don't worry about on any length of ride due to battery power, but I'm not exactly sure how to get there yet. Most fully programmable CDIs are pretty expensive. I've wanted an MSD 4217 for years, but it's $400+ for just a CDI. Other brands make them as well, but none of them are cheap. If I knew for sure I could make it work, I'd probably go for one. I'm afraid the MVT may not work with them, and even worse, may damage a CDI. The MVT doesn't seem to have a pickup/trigger wire. I'm not sure if it uses the exciter signal as a pickup or how it works. If it is using the exciter signal as a trigger, then I would think that may be enough to fry a CDI that's just looking for a low voltage signal for the pickup. Not cool when you put out hundreds of dollars for a CDI. I've got an AliExpress DC CDI that is supposed to allow full control of the curve up to 16,000RPM. I bought it for a 4T years ago and never got around to trying it. It was still $70-80 IIRC, but at least it's not hundreds if I fry it. I may try to see if that works at some point, unless someone knows of an MVT compatible CDI that doesn't have the huge lower RPM advance like the standard and EPROM from MVT. Can't do it. I've tried I think 4 different lights and none can keep up to measure it full song. The closest still quits before that. Don't ask me why I managed it once on a Minarelli MVT and with the Piaggio MVT I can't get there. The good news is, the curve that I recorded on the Minarelli seems to match what the Piaggio MVT I'm using now is doing up as far as I can see with the light working. That doesn't tell me for sure what it's doing at 14k, but it's as close as I can get. I had the same thought on the last set of runs... but it died before I got there. Prior to that, it was high enough that I've had it leak when leaned over on the stand a couple of times and I'll see some evidence of dribble at times. I could run it with huge jets and it would keep acting rich all the way through a run. That doesn't mean something didn't mess up toward the end, but it appeared as if once I put the CVT tune in the RPM sweet spot it suddenly got hot. I had the same thought on the needle tuning as well and what John linked me to supports that idea as well. Setting it to 0.31mm BTDC would be essentially the same as where I started. I started out on 0.35mm BTDC and that's when it was giving me 1400 degree EGT readings unless I used huge jets or no main jet at all. 0.04mm is basically a half a degree different from where I was. I've ran 0.35mm since the day I put the RC-1 together and never changed it till the big carb gave me high WOT EGTs. I've got some muriatic acid that I'm gonna try to see how much of the marking is transfer from the piston and how much is actual damage to the cylinder. Gonna try to be sparing with it on a Q-tip and hope I don't get any in a port. Hoping I'll get lucky and that and some Scotch Brite will make it good enough and I can measure and see if a C piston is still what I need or not. I've got ball hones too, but I see some people say a couple of quick passes are good and some say don't touch a plated cylinder with a hone and crosshatch is not so necessary on plated aluminum as it is on iron jugs so I was just gonna go with some hand work where necessary. Thank you for the offer!
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Post by 90GTVert on Dec 11, 2023 9:00:13 GMT -5
And the person who told you nicasil plating doesn't need cross hatch shouldn't come near any engine. Let me know if you need help. Good luck! Here’s one source of the anti-hone info. Slavens Racing. Generally reputable source of info from what I recall. This is where I struggle with many things. You can find people that do things regularly and seem to know their stuff in general and they will contradict each other on even what should be pretty ordinary jobs for folks in MX and saw shops. Of course I have a comment on the 2000+ mile inspection that most would have had a new cylinder by then. Not exactly sure why you'd toss one out just due to that many miles. At this point, even if I get a different cylinder, I'm hoping to have another go at the tuning with the old cylinder and a new piston before putting something brand new in and risking it off the bat... though I agree that I'm less likely to have so much trouble if I can find a way to have less advance down low. I have sanded out some stuff with scotch brite before but I have at least one spot that is a substantial buildup of aluminum. That’s not gonna sand out easily and honing long enough to get that out wouldn’t be a great idea. Muriatic acid is a common go to for that sort of thing. Others go after it with a rotary tool and sanding drums or burrs. Those seemed a bit aggressive to me. This is like reading Amazon reviews where 50 people love it and 50 people hate it and suddenly you don’t know what’s real. What methods do you use?
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tysta
Scoot Member
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Posts: 74
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Post by tysta on Dec 11, 2023 10:01:54 GMT -5
I did press play just to see what he was going to say and right on the first 30s he prove himself not knowing at all what he is talking " nicasil is sprayed on " hahahaha Nicasil was first used in the 60's and before that something chromonickel coating. Most people talk out of their axxxx If you wouldn't need cross hatch after the cylinder is bored you could finish the job by polishing.... I don't understand how people get this stupid ideas sometimes 😂 If the cylinder starts to get glazed you start to lose efficiency the small groves won't collect oil The correct angle is also important all of this to ensure a proper ring seal and the right amount of lubrication in the rings. The piston it self already have the groves to keep oil. It depends alot on case an how much deposit. Some cases my require a use a fancy nylon bur to remove the left over aluminum. And the person who told you nicasil plating doesn't need cross hatch shouldn't come near any engine. Let me know if you need help. Good luck! Here’s one source of the anti-hone info. Slavens Racing. Generally reputable source of info from what I recall. This is where I struggle with many things. You can find people that do things regularly and seem to know their stuff in general and they will contradict each other on even what should be pretty ordinary jobs for folks in MX and saw shops. Of course I have a comment on the 2000+ mile inspection that most would have had a new cylinder by then. Not exactly sure why you'd toss one out just due to that many miles. At this point, even if I get a different cylinder, I'm hoping to have another go at the tuning with the old cylinder and a new piston before putting something brand new in and risking it off the bat... though I agree that I'm less likely to have so much trouble if I can find a way to have less advance down low. I have sanded out some stuff with scotch brite before but I have at least one spot that is a substantial buildup of aluminum. That’s not gonna sand out easily and honing long enough to get that out wouldn’t be a great idea. Muriatic acid is a common go to for that sort of thing. Others go after it with a rotary tool and sanding drums or burrs. Those seemed a bit aggressive to me. This is like reading Amazon reviews where 50 people love it and 50 people hate it and suddenly you don’t know what’s real. What methods do you use?
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