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Post by Lucass2T on Jun 28, 2023 9:30:10 GMT -5
Been seeing a lot of love given to MVT here on this forum. When does it become worth and/or noticeable to do such an upgrade? Do you only reap the benefits with something high end that revs to the moon our would you see it with a sport kit or even stock-ish setup? I would expect it to work best with at least a midrace kit, and you may have to set the base timing to give it less advance. With stock or sport, you could have a lot of advance in the powerband. When I first installed an MVT it was with my 86cc and a Peace Pipe so it stayed 10-11k and it was a nice improvement for me. The video with details about that and all of my MVT setup info is in the thread below. 49ccscoot.proboards.com/thread/26257/dd06-ignition-info-timing-graphsAgree. Myself Id start thinking about performance ignitions when you are at the higher end of a midrace setup (bridge port alu cylinder, 19+mm carbs, Yasuni C16 and up). You could also consider a performance CDI with advance curve which replaces the stock one. Like the red top performances one www.scooter-attack.com/en/product/cdi-woodruff-key-top-performances-minarelli-horizontal-68330Or the Athena one www.athena.eu/en-us/cdi-kit-with-settable-advance-P27982.htm cdn.athena.eu/2b649af1-fc18-403c-91c0-c6bf7c2bc1e2.pdfYou could also make a distinction between an inner and outer rotor type. Where innerrotor types are aimed at racing (weak/no lighting but very snappy throttle response) and the outterrotor types (bigger power output but slower throttle response). I think MVT carries both types? I once put a HPI inner rotor ignition with a curve on my old points ignition Puch maxi. It had a setup you could compare to a midrace setup (high end 70cc alu cylinder, 19mm carb, racing exhaust). It was pretty snappy in its powerband but a total dog below. After putting an inner rotor HPI ignition on it, it totally came alive everywhere below the powerband. Made a huge difference!
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Post by awines2326 on Jun 28, 2023 11:58:51 GMT -5
I have the HPI inner on my Honda Hobbit running the 70cc LC S6 R/T & an aluminum clutch plate on the other side. It's about as responsive as possible, but the inner rotor gives me 0 power output so there's a price to be paid there.
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Post by Lucass2T on Jun 28, 2023 14:14:11 GMT -5
I have the HPI inner on my Honda Hobbit running the 70cc LC S6 R/T & an aluminum clutch plate on the other side. It's about as responsive as possible, but the inner rotor gives me 0 power output so there's a price to be paid there. There are tiny lighting coils availabe for the inner rotor version. I have one laying around. Or go with the HPI 2-ten which has something like a 80W output.
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Post by 90GTVert on Jun 28, 2023 18:30:10 GMT -5
I don’t need another 12.5 degree fixed half… but it would bug me if I didn’t see if one could be cut successfully without thinning the center too much so I cut the Malossi half that Ryan sent today. I put an indicator on the carriage this time. Otherwise I’m just bumping it forward and totally guessing. I went slow on feed and speed and cut 0.010” for three passes and then 0.0065” finished the whole face. So 0.0365” cut. It was a pretty good finish. Not very rough like past attempts. I cut as close to center as I could with a pointy bit before sanding with 400 grit and oil a bit and then shining it up a little. Shining it up made it look worse, but it’s a decent finish. I chucked it up a different way and cut the very last bit in the center. Looks thick enough to work just fine. It could be sanded more to try to get the lines out, but I figure the more I sand the less flat it is and the finish seems good enough to me. Now, is it of any use? Eh… I’ve done a couple sets of tests with the 12.5 stuff (using the S6 fixed half) and it ain’t working for me. I was quicker with the 14 degree setup. Gotta gather RPM and EGT info from video to add to the dragy data in my spreadsheet, just to be sure I’m not totally missing the mark. Times are far enough off that I don’t think so.
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Post by 190mech on Jun 28, 2023 19:30:19 GMT -5
Brent, Glad to see your machine shop is still going strong!What would we do without these tools?? I just watched your S6 pipe install vid, the removable stinger with the insert is the "Fath Nozzle" designed waay back by Helmut Fath in an effort to make pipe tuning track adjustable without a torch.. Frits Overmars gave us this wonderful drawing of the concept; Cheers, John
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Post by 90GTVert on Jun 29, 2023 12:10:36 GMT -5
Brent, Glad to see your machine shop is still going strong!What would we do without these tools?? I just watched your S6 pipe install vid, the removable stinger with the insert is the "Fath Nozzle" designed waay back by Helmut Fath in an effort to make pipe tuning track adjustable without a torch.. Frits Overmars gave us this wonderful drawing of the concept; Cheers, John Thank you for the info! Someone in the comments just got the idea right (at least AFAIK) too, saying it's a way to narrow the opening to the stinger using a stuffer. The questions that come to mind for me are : Why does absolutely nothing relevant show up if I search for "Fath nozzle"? Why aren't different nozzles listed anywhere as tuning parts? High end racing stuff doesn't seem like the place to worry about burning pistons if someone tries a different nozzle. I get why anything small wouldn't come stock so some dummy like me wouldn't bolt it on and bitch about my trashed engine. Also, how critical is the 10° angle on exit? Is that a must and you can only adjust diameter within limitations due to length? I say length for 2 reasons. One being clamping area available to hold the piece and stinger and the second being for tuning reasons as well. Can the angle of entry from the convergent cone change as needed to accommodate outlet changes or that should be a set angle too (or match the cone)? This seems like a good example of the black art of tuning. Some people know about it, but it's sure not well known. I guess you're making your own if you wanna try it too?
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Post by 190mech on Jun 29, 2023 18:37:53 GMT -5
The google search on kiwibiker is now inop, so finding that term is impossible..Frits also called it a tail restrictor..I dont think the entrance and exit tapers are super critical,but the restrictor diameter is for the build..808ministoke got a pipe for his scoot and it had some different restrictors included..Both Frits and Wobbly at kiwibiker talk about the importance of them on high end racing liquid cooled engines,,just cant find their quotes now!!
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Post by 90GTVert on Jun 29, 2023 21:39:28 GMT -5
I noticed the search issue when I looked too. I tried other search engines and swapping the : for = and couldn't get anywhere. Seems to be an issue with the thread/forum, because it works fine on other sites.
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Post by 90GTVert on Jul 4, 2023 21:59:41 GMT -5
I rode T2 to the beach a couple of weeks ago and it turned out so well that I tried again today. Today did not go so well. It was in the low to mid 90s and humid, and the scoot didn’t like it. It struggled to idle and broke up really bad below 1/4 throttle… which is all of my slow cruising. I tried multiple times to adjust the idle mix and speed, but I couldn’t make it idle well today. Most of the time I’d stop to adjust it and it would idle OK and then the next stop light I have to babysit the throttle and it sounds like it’s making the dreaded wah sound. It died at a red light and I couldn’t get it to start. Had to do the walk of shame. Naturally at the route 90 bridge intersection, where traffic is coming in from another highway. Most intersections I could just turn right and be done. I changed the spark plug and it ran again. At that point I had only made it basically halfway one direction of my usual loop, so I decided to finish a whole loop. Now I wish I didn’t. Never stopped again, but I was dreading every light. Of course some Audi took off trying to race me and I was just trying to get moving. A lady made the mistake of pulling up beside me on a bicycle and it happened to be the worst takeoff I had all day. I smoked her out and swerved around as it didn’t get moving well at first. It felt weak up too too, but RPM was low. Maybe Related to me using 0.8mm of shims bs 1.0 normally? I came through a town on the way home and people were lining the streets for some event. Thank goodness a crisis was avoided when I could muster wheelie power as a kid gave me the throttle twist hand gesture. The scoot seemed really loud on the way home. My hearing is quite dull now. Noticed a broken silencer clamp. Who knows what else is up? That shouldn’t make it loud on its own. Prob time to repack anyway. I found a broken bracket for my little behind the seat box before I left. Zip tied it, but I’ll need to actually fix it. I noticed the headlight was crooked when it was aimed at the garage door before I came in. Found the headlight out of place in the housing. I also noticed that it wanted to bump right as it got moving sometimes. Gonna need to see what that’s about.
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Post by Lucass2T on Jul 5, 2023 1:18:58 GMT -5
Ahh thats super annoying when theres multiple things at once that needs fixing. Luckily you have a nice big garage stocked with tools and parts.
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Post by 90GTVert on Jul 6, 2023 16:54:36 GMT -5
Someone just told me in a YouTube comment that they use CVT FR4 variators for drag racing in Italy. I looked those up and they have some ideas that I don't recall seeing before. The variator and ramp plate have an angular pathway built in, so it acts as a torque driver. They claim it provides better control and less belt slip, among other benefits. www.cvtfr4shop.it/epages/85798.sf/en_GB/?ObjectPath=/Shops/85798/Products/1They also sell racing rollers. They basically have a groove in their outer surface which should create less friction and they say helps cooling as well. I'm still sticking with sliders, but it's interesting anyway. www.cvtfr4shop.it/epages/85798.sf/en_GB/?ObjectPath=/Shops/85798/Products/13Not sure that they have anything suitable for the RC-One. They have a Piaggio version that says 50, 70 or 90cc. Only 50cc is available. The 50cc has the heaviest weights so I'm not sure if that means there are different designs for say a 90cc or if that's related to the torque driver operation. I'd expect the 90cc to use heavier weights if all else were equal. Wanted to share anyhow.
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Post by aeroxbud on Jul 7, 2023 4:36:24 GMT -5
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Post by 90GTVert on Jul 7, 2023 7:36:51 GMT -5
Those are the things that go in the variator to interact with the tangs on the ramp plate. Basically like what I'd call guide bushings or many call sliders in a traditional variator. The person that mentioned CVT FR4 got back to me and said they use them a lot for more stock applications, not something like the RC-1. Now it makes me wonder if they just don't work as well with high RPM/high output or if the 50-90cc stuff doesn't hold up to that level of abuse or what.
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Post by 90GTVert on Jul 11, 2023 10:30:45 GMT -5
I fixed the crooked headlamp this morning. It's supposed to have 3 clips holding it in the housing, but only 2 were present. I saved the clips from my damaged headlight after the deer crash, so I had spares.
I took the exhaust off and took some measurements. I just ordered 1.5" wide by 0.060" thick stainless steel that will hopefully work for the clamp. It's a little wider and a little thicker. The rubber is gone, but I've got some around that should work.
The o-ring for the header connection is bad and it's spitting oil now. Can't find a Malossi replacement, so I ordered a couple of high temp o-rings from McMaster-Carr along with the SS that may work. There's really nothing meant to hold up to the kind of heat that the header could see. The best I saw are 570-something degree rated. I went with 2.5mm thick, 38mm ID (43mm OD) for the flange to cylinder connection and 2mm thick, 36mm ID (40mm OD) for the pipe connection. Not sure that they'll be right, but maybe good enough.
That was just over $70 shipped, which is why it'd be nice if replacement parts were widely available. The clamps are out there, but the cost of one with shipping is most of the price of 3ft of stainless, which should make a few clamps if it works. The Malossi clamp on my 86cc broke on one of the last rides that I took with it so I need more than one anyway.
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Post by 90GTVert on Jul 14, 2023 7:50:17 GMT -5
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