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Post by 90GTVert on Jun 10, 2015 17:12:57 GMT -5
You'd have to know the RPM the primary driveshaft turns, so you'd need to know engine RPM and CVT ratio for that. That part I'm not real sure of. The countershaft is the slower of the two primary gears, about 1/3 the revolutions of the drive shaft. If you leave the CVT out of the equation, I'm around 9000RPM topped out so it would spin at roughly 3000RPM. So maybe 3-5000RPM range with the CVT?
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Post by 190mech on Jun 10, 2015 17:13:24 GMT -5
Ive made quite a few 'desperation' reamers over the years.Find a piece of high grade steel thats easy to obtain,the right OD and grind cutter flutes with a dremel cut off wheel.Lots of the 250 MX bikes use an 18mm piston pin,also the big end pin on a 90cc Mina crank is 18mm,,,Food for thought..  |
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Post by 90GTVert on Jun 10, 2015 19:38:14 GMT -5
I swear you know every trick in the book John.  I just did a pressure test. Failed again. Leaking in a different spot at the base. Instead of a very thin aluminum spacer and a gasket with ThreeBond, I switched to a thicker spacer I had and no gasket. Coated it with Ultra Grey this time. Installed it at a few ft-lbs and I'll let it set up some. Then I'll torque later. |
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Post by 190mech on Jun 10, 2015 20:04:20 GMT -5
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Post by 90GTVert on Jun 10, 2015 21:41:56 GMT -5
Thanks again.
The case leaked big time. When I took it apart the Ultra Grey had clear imprints of the case and cylinder, but was only bonded to the spacer. The cylinder and case were basically clean. I guess either I needed more torque or I should have put the Ultra Grey on all surfaces. I put it together quickly so I didn't think it would be an issue.
Cleaned it all again. This time the thicker spacer with ThreeBond. Tomorrow I can see where that leaks and then walk away defeated. Damn these simple two-strokes. lol
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Post by 90GTVert on Jun 11, 2015 16:39:36 GMT -5
I went out this morning and it leaked really slowly. There was basically a pinhole leak on a corner. Different spot than all the others. I did something half-assed, what's new?, and used a plastic knife cut thinner to spread a layer of ThreeBond over that area. Not exactly how I'd prefer to get a seal, and I'm not terribly confident in it. I'm running out of time though if I do want to try going anywhere this weekend. Came back around noon and it held 6psi for 30 seconds and I disconnected it before it disappointed me. Again, not exactly how I'd prefer to do things. I got the gearbox together. I decided to use the 13.52 gears. That way I don't have to swap things in and out. Maybe not ideal for possibly taking a 200 mile ride, but they will work for a spare. The drive shaft of that gear set is another that's worn and needs shimming so the bearing can't move around. Fun as always. I eventually got about half of the shim actually in there and not crinkled up and used some retaining compound on it for good measure. I checked squish clearance and it was about 0.9mm. Compression reading was 170psi. I put a Hoca variator and a Hoca rear pulley on it with the usual Bando belt. I like the OR variator, and I have no e-start anyway, but I want to leave everything alone on the engine I was using. I really would like to find out where the poor times came from all of the sudden with it, so I'd rather not move parts back and forth if I don't have to. Started out with a 1000RPM contra, 1000RPM clutch springs, and 7.5g sliders with 2mm of spacing to keep the belt from being squeezed. I stuck the carb back on just as it was setup for the other 103cc. The stator on this engine is a new stock unit that I stuck on it when T1 was having spark issues. Since it was never modded and the flywheel had no timing mark on it, I wanted to figure out where the base timing was. It makes enough difference that even without a lot of time to spare I wanted to put the effort in to be sure it wasn't one of the 13 degree flywheels. I found TDC and setup the timing light. Turns out it was at 13°BTDC. I wanted to move it to about 17° so I had to mod the stator plate.     I ended up at 17.5 degrees after a couple of tries and called that close enough. If I end up hearing spark knock I'll back it off. Managed to kill the clutch in my drill using it to start the engine. So far all I've done is take it across the yard real quick. It wants to die after I rev it up, so the carb needs work. The 7.5g sliders were too light so I swapped in 8.5g. Yesterday I decided to take on a project while waiting for sealant to cure. The inability of centerstands to lift the rear tire off of the ground in some cases was discussed on the forum recently. Made me think about mine, which hasn't lifted the tire for a very long time since I've used a longer rear shock and taller tires didn't help. The easy solution seemed to be welding something to the bottom of the stand to make it taller. I just have to do things the hard/dumb way though. I cut the legs in half and welded 1" of steel tubing into each to lengthen them.  One bad thing is that the tubing I had is thinner walled than what the stand used. I will probably reinforce it later.  I can see a small amount of daylight under the tire now. It feels way more stable on the stand. Before I could roll the scoot around with the stand down and it rocked back and forth. It's a lot more difficult to get it on the stand now, but that's prob just because it works as it should and I'm not used to that.  I welded one side back together clocked wrong. The legs are supposed to aim in a little, like toe-in. The left side is in too far now though. I marked the legs before I cut them, but when I welded the extensions on it burned through the paint higher up than I though and I had no mark. My guesstimate looked totally wrong once I installed the stand on the scoot. I'll chop it off and redo it sometime. It makes the extension aim downward. I don't really think I'll have clearance problems with turns, but it would probably make it easier to get it on the stand if the extension was flatter. |
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Post by niz76 on Jun 11, 2015 17:00:38 GMT -5
Centerstand looks factory!
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Post by 90GTVert on Jun 11, 2015 20:51:50 GMT -5
I'm gonna ride this thing to the beach... straight into the ocean. Done.
Just getting tired of messing with it ATM. First run down the road sucked. Ran up to about 50MPH. Turned around and it ran terrible, up to about 40 WOT. Fluttering like it was rich. Pulled the plug out... dry. Oh well, I know that feels like rich. Put a 96 main in place of the 100. Much better. CHT went up to 331. Not sure if that's good or bad with this thing. Last setup ran up to about 315, but I didn't put time into the carb to know for sure what the CHT would say when it was really well in tune. Plus this thing seems to be affected by the wind hitting the head, and this is a different head and a different shroud. Numbers mean basically nothing to me at this point.
On both runs it had very noticeable shifts. The Hoca is a straight groove TD, but it felt more like I had a stock dual angle in there. I decided to make sure I hadn't swapped a stock TD onto the Hoca fixed half for some reason. Didn't think I did, but it really felt like a TD shift. I also had some strange slipping on takeoff once.
When I took the clutch bell off there was a little gear oil residue on the clutch pads. Closer inspection revealed a leaking drive shaft seal. I didn't replace it when I did the bearings because I hoped it would be alright and I wouldn't have to use the spare I bought when I got one for the other engine. Replaced it tonight. Took the rear pulley apart and it was indeed the straight groove Hoca. I cleaned it and regreased it since I was in there. I also swapped from 8.5g sliders to 8g because it felt like it bogged a bit when it shifted.
Put it back together and went to fire it up. Nothing. Checked and I had spark. Kicking felt normal. Pulled the plug out and it was dry. Stuck an unlit propane torch in the airbox and kicked it a few times and it fired up. It was fine after that.
Rode it about 7 miles, aggravated the whole time. I forgot to take the black visor off since it's dark and mosquitoes were out in force so it was either be blind or have mosquitoes in my face and ears. I alternated between the two. Anyway, back to the scoot. So now the shift seems to happen whenever it feels like it. One time it shifts at 45MPH. Another time it shifts at 25MPH. Another time it felt pretty good but once I was almost topped out RPM started dropping. Maxes out just over 50 as expected. I think 53MPH is the fastest I saw. The CVT feels very engaged vs the Malossi setup. Meaning if I let off and get back on, it's more likely to "chug" then to rev and go. It was prob a terrible time to not use the easier to setup Malossi. Gave up for the night.
The weather guy said tonight that Saturday probably won't be a total washout, but you will need your umbrella. Frustrating myself for no reason if that's how it turns out.
Oh, and the centerstand sucks. The first corner I went into at 50MPH I heard a sharp noise. Thought it was some awful spark knock at first. Let off and realized the stand on the left where it's clocked wrong was hitting. I don't think it would be an issue, but the spring for the stand is worn so it hangs lower and bounces around. I've needed to replace that for years. As I've said before, most of my stuff is getting old and worn out. Chinese parts don't seem to be meant for lots of miles and harsh use.
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Deleted Member
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Post by Deleted on Jun 12, 2015 7:20:15 GMT -5
You get the Lifetime Achievement Award for Patience & Endurance under extreme aggravation.
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Post by 90GTVert on Jun 12, 2015 11:21:26 GMT -5
Thought I'd be working on it this morning, but first I had some site related stuff I wanted to look into. Then I needed to take trash and the truck wouldn't start. When I turned the key on in the truck I had St. Anger in there by Metallica and it was right at the verse "it feels like it only rains on me".  The truck starts most of the time now... I think maybe a starter relay or relay connection issue... may have just bumped it when I took the fuel pump relay out last week before doing a fuel filter... so I can start directing my curse words at the scoot now.  |
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Post by 90GTVert on Jun 13, 2015 18:13:42 GMT -5
I've been waiting for proboards to clear up the issues with forums before updating. Didn't much like the idea of posting without previous info there. Yesterday I decided that I needed to focus on just one thing. Initially I was trying to get a quick ballpark tune, but it was fairly obvious that it wasn't going to be easy with this one. I wanted to start with jetting. I did runs and plug chops the same with 3 main jets. I went 2.5 miles WOT other than having to make a turn onto a different road. I turned around and came back WOT again other than that turn. New plugs each time. I started out with the 96 main jet. I had swapped it in earlier because it seemed rich with the 100 main jet. I now think I mistook the odd CVT actions bogging down as a rich condition. The CVT seemed to do it's own thing and inconsistently so it makes it tough to tell what's really going on. Yesterday at least it seemed to run consistently poorly as far as the CVT tune. With the 96 main jet it ran alright, but CHT peaked at 372F. At the very end of the run it acted like it was getting low on power, this was near peak CHT so I assumed it was about to seize. The night before I ran it WOT for a bit, not 5 miles pretty much straight though, and it was only 331 max. It was about 90-95 degrees yesterday though and the other ride was 80 something and the sun was setting or down. I swapped to a 100 main and tried again. It ran fine this time, again until about the end of the run when it got to 360F max and started to lose some power. Unfortunately it was really windy yesterday, and it was losing power when I was directly head on into the wind. It wasn't just the wind though, because I could feel that it wasn't all there when I let off and got back into it. I came back and swapped in a 105. I can't recall needing a 105 main jet with this airbox and any other 90-100cc. Again it ran well, but on the home stretch it heated up to 367F max and started losing power. Here are the plugs :     It seemed strange to me that it would get hotter with a larger jet. There's also a sort of warble. It does not sound smooth WOT. Knowing I had sealed a leak by putting more sealant over an already cured area doesn't make me very confident in it. A proper seal at the base gasket should have the pressure of the cylinder and cases torqued down to help it seal. As I said when I did it, it was half-assed. I decided to do it right and give it another leak test to see if it indeed sprung a leak as I suspected. I put the pressure tester on and within 5-10 minutes it went from 6psi to 0psi. Before I worry about any more tuning I want to get the base to seal. I have had case leaks that would make rich tunes seize and also cause a fluctuating tone at WOT before, so I felt it best to call the ride off and just do it right. That way I'll have a good spare too, not just something that sorta runs... and hopefully I won't find myself miles from home with another melted piston. One thing I did during the tuning was to enlarge the center of the thermocouple. The thermocouple was tight enough that it had to be screwed onto the plug. It made installing and removing the plug more of a pain than it needed to be. I took a burr to it and opened it up just enough that it would slide over the threads. I also fixed the worst side of the center stand. I chopped it off and welded it back on so it was clocked better. I didn't even bother to take it off of the scoot.   Now it sticks straight out rather than aiming at the ground. The dragging on turns was bad enough, but I also kept stabbing my toes when I leaned the scoot to maneuver it around the garage before.  |
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Post by Fox on Jun 13, 2015 18:40:51 GMT -5
Looks like making the leg longer made that lever stick out more. Maybe you can turn the S curve it has now into more of an L shape by heating and bending to bring the lever part a bit higher up and closer into the belt cover. Then it would take a greater amount of lean to make it scrape on the ground.
I see that the right side also has a lever sticking out. I would just cut that one off altogether unless you use it. Seems redundant to me.
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Post by 90GTVert on Jun 13, 2015 18:51:32 GMT -5
I thought about chopping the other side down. The one plus of keeping it though is that if the scoot starts to tilt it will hit that leg rather than just going over.
I think the other side will be alright. I should really replace the springs so it doesn't sag and bounce around so bad when I ride. If it stays up it would take a good bit to scrape it now.
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Post by iwiketuddlz on Jun 16, 2015 8:48:42 GMT -5
Lookin good vert!!!!!.... Man I miss my center stand .... Darn EvO.......
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Post by 90GTVert on Jun 16, 2015 9:56:16 GMT -5
I haven't done anything with either of the 103ccs. It's been very hot and humid, but mainly because I've had some other stuff going on. Since I mentioned it earlier, I had no luck on a cheap reamer through the hardware store my father works at. Nearest they had was 23/32" (about 0.010" larger than I needed) so no good for me. Said it was $11, but with freight because it's a special order from a place they don't use a lot it would still be about $25. I prob would have bought it if it were the right size, because I don't know how well I'd do at making one. Sooner or later we'll find out though. I should have a crank pin from a botched crank job around here unless I already scrapped it.
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