chico357
Scoot Member
Str8 Scootin'
Posts: 67
Location: Pompano Beach, FL
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Post by chico357 on Jan 18, 2017 15:51:30 GMT -5
So I took a nice ride today for lunch as it was a nice day to ride here in Boca Raton; 76°, Wind speed is 7mph SSE On my first run I rode westbound for about 8.75 miles. Wind Speed 7mph SSE 53mph @ 8850 RPM 55mph @ 8740 RPM Max RPM @ 9600 RPM Max speed 55mph Launch Speed 4750 Shift out Speed ~8500 RPM Second run was eastbound going back the same way. Due to traffic, I wasn't able to get the same top speed: 50mph @ 8500-8800 rpm 52mph @ 8640 rpm Max rpm @ 9200 rpm Max speed 52 mph @ 8640 rpm Launch speed @ 4770 rpm Shift Out @ ~8500 rpm I did some 0-30 Runs and quarter mile runs yesterday too: 0-30: Quarter mile: I also have a lot of data from runs I did with just the big bore upgrade. I have to sort through it all along with my notes. I'm hoping to make a separate post about my build soon.
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Post by FrankenMech on Jan 19, 2017 3:58:45 GMT -5
A burr on a shaft or gear ID can cause runout in the gear that may produce a tight spot. Burrs on the gear teeth may also cause a tight spot. Inspect everything thoroughly before assembly.
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chico357
Scoot Member
Str8 Scootin'
Posts: 67
Location: Pompano Beach, FL
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Post by chico357 on Jan 19, 2017 7:51:45 GMT -5
A burr on a shaft or gear ID can cause runout in the gear that may produce a tight spot. Burrs on the gear teeth may also cause a tight spot. Inspect everything thoroughly before assembly. I am almost certain that is the issue. The gears were new but looked like they were in a pile with other gears and had some minor imperfections on the teeth. I did lightly file them just to make sure they were rounded out. I had them for like 6 months so there was no way I was going to be able to return them. The dealer I got them from doesn't offer them anymore either which is one reason I was suspecting the gears. I probably got the last set that some one else returned. Oh well...live...learn...and just keep on scootin' I guess. I was already planning on opening the gearbox this weekend for inspection. I'll probably order another set from somewhere else too. Thanks
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Post by FrankenMech on Jan 19, 2017 19:16:00 GMT -5
Some factories use a deburring process where parts are tumbled with ceramic media of various sizes. Kind of like polishing rocks. It is not suitable for certain types of parts like gears. Throwing (previously) precision parts in a bin with other parts is not appropriate either.
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Post by dexameth on Jan 20, 2017 12:17:20 GMT -5
I got mine installed yesterday, no tight spot, spins free! I don't have it tuned in right yet, but I still drove it to work and hit 59 down hill... I'll post up pics later when I'm not on the clock...
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Post by dexameth on Jan 20, 2017 13:16:50 GMT -5
So I had a guy use a 20ton press to get them apart and back together. Here's what I got: I asked him to close the little gap, and he said he had heat AND 20t on it, it's as far as she will go. I installed it fine, and was so excited these are my only pics: See the difference between stock and aftermarket (Glixal)? These are my halfway point pics, nothing really special. After the install I went for a cruise, keeping the transmission the same. It felt a little faster, but rpms needed to come back up. Went from a 7 and 5 gram slider mix to all 5 gram. A little too high on the RPM scale, top speed was back to 52. This morning I did a mix of 7 and 4 gram sliders to mimic 5.5gram and I love it. I swapped out the variator drive boss for a shorter one and no go. It drives, but the clutch engages instantly for too low of RPMs at take off... Bye bye wheelies )': so tonight I'm going out with the short boss and in with a long boss and I hope that will even it out.
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Post by dexameth on Jan 24, 2017 20:35:24 GMT -5
So... Tuning these gears are hard without my array of mixed rollers and sliders. I just can't get the right RPM range I'm looking for. Tougher contra springs greatly reduce my top speed no matter the weight of rollers or sliders or length of drive boss. Stock contra with original 7/5g slider mix is okay, but rpms are a tad bit low and take offs suck. No wheelies ): Stock contra with 7/4g mix (only 3 grams lighter mass) and the RPMs are a tad high. Wheelies are doable, takeoffs are nice but top speeds are 48ish. I haven't tried my blue (1k) contra yet. Gonna need lighter weights (I have 4 and 5g sliders to test) but I've noticed in the past a lighter spring makes "downshifting" horrible. The belt will get stuck in high gear after slowing a little. Also, my last air filter rubber boot on the carb failed, so I went to a local scoot shop and they sold me an air filter with a smaller inlet... This killed my performance. Had to notch the carb needle down to help balance throttle fuel mix. Before work tomorrow I'm going to do blue contra, 4/5g slider mix and stock drive boss. Thursday I'm gonna pick up a UNI filter that will breathe better. All in time, I'll hit 60!
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Post by FrankenMech on Jan 24, 2017 23:11:36 GMT -5
John at TVNACMAN has good air filters without that restricted opening. Finding a supplier that will actually post pictures of the filter outlet like that is rare, probably because most of them are selling that restricted model. The restricted one is probably a one size fits all metal housing with different size rubber pieces that snap into the small hole.
It is too bad these little engines puke so much fuel out of the carb inlet. I think part of that may be the improper fuel bowl venting and the fact that all fuel/air mix travel stops abruptly with no other cylinders drawing mix to keep the flow going.
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Post by diynuke on Jan 25, 2017 4:54:14 GMT -5
Guys would it be useful for an 72cc gy6 to do a gear swap? or would it just reduce speed?
Greets DiyNuke!
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Post by dexameth on Jan 25, 2017 14:15:43 GMT -5
Guys would it be useful for an 72cc gy6 to do a gear swap? or would it just reduce speed? Greets DiyNuke! I don't know if a 72cc would have the power... I'm at 83cc and just today I was able to maintain 55mph tucked using 5 gram sliders. I have been battling with roller/slider weights and contra springs and it seems like I'm just barely able to push these gears. Even using a slight bit more restrictive air filter was giving me hell. I tested a run today with, eh heh, no air filter. Open carb and my needle adjusted for more fuel at WOT. It definitely helped. Tomorrow I will be installing a 24mm carb and intake from a stock 150 just to see if it opens up some power. More power means heavier weights means more GO GO!
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Post by dexameth on Jan 28, 2017 9:54:37 GMT -5
So I took a nice ride today for lunch as it was a nice day to ride here in Boca Raton; 76°, Wind speed is 7mph SSE On my first run I rode westbound for about 8.75 miles. Wind Speed 7mph SSE 53mph @ 8850 RPM 55mph @ 8740 RPM Max RPM @ 9600 RPM Max speed 55mph Launch Speed 4750 Shift out Speed ~8500 RPM Second run was eastbound going back the same way. Due to traffic, I wasn't able to get the same top speed: 50mph @ 8500-8800 rpm 52mph @ 8640 rpm Max rpm @ 9200 rpm Max speed 52 mph @ 8640 rpm Launch speed @ 4770 rpm Shift Out @ ~8500 rpm I did some 0-30 Runs and quarter mile runs yesterday too: 0-30: Quarter mile: I also have a lot of data from runs I did with just the big bore upgrade. I have to sort through it all along with my notes. I'm hoping to make a separate post about my build soon. Hey what app do you use? I'd like to get better data like that.
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Post by FrankenMech on Jan 28, 2017 17:22:22 GMT -5
I need more torque to deal with the constant up/down hills around here. I decided to just go with a 125-150cc engine. I hope to pick one up soon.
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Post by dexameth on Jan 28, 2017 20:06:08 GMT -5
I need more torque to deal with the constant up/down hills around here. I decided to just go with a 125-150cc engine. I hope to pick one up soon. Yeah, Florida is pretty flat. There's a few bridges around connecting beaches, those are my hills. Still a pain on a stock 50. I finally got my Keihin 24mm 150cc carb installed and adjusted the needle all the way up (most fuel delivery). Man there's torque!! Yesterday I had a stock 150 carb on and it work, but bogged when the throttle opened too fast. I figured it was a velocity thing. More like too lean. After I adjusted the needle, the throttle is definitely snappy. I was pulling up the bridge today at 38 and still accelerating. I was holding 55 on US19... I'm gonna have a re entry on the speed list soon. I even got my wheelies back finally! Kinda lost them since the 49/17 gear swap but not tonight. I really wanna port match my head now and get the Airsal piston. Don't give up on your QMB!
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chico357
Scoot Member
Str8 Scootin'
Posts: 67
Location: Pompano Beach, FL
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Post by chico357 on Jan 30, 2017 8:33:30 GMT -5
So I took a nice ride today for lunch as it was a nice day to ride here in Boca Raton; 76°, Wind speed is 7mph SSE On my first run I rode westbound for about 8.75 miles. Wind Speed 7mph SSE 53mph @ 8850 RPM 55mph @ 8740 RPM Max RPM @ 9600 RPM Max speed 55mph Launch Speed 4750 Shift out Speed ~8500 RPM Second run was eastbound going back the same way. Due to traffic, I wasn't able to get the same top speed: 50mph @ 8500-8800 rpm 52mph @ 8640 rpm Max rpm @ 9200 rpm Max speed 52 mph @ 8640 rpm Launch speed @ 4770 rpm Shift Out @ ~8500 rpm I did some 0-30 Runs and quarter mile runs yesterday too: 0-30: Quarter mile: I also have a lot of data from runs I did with just the big bore upgrade. I have to sort through it all along with my notes. I'm hoping to make a separate post about my build soon. Hey what app do you use? I'd like to get better data like that. Check out this cool app: play.google.com/store/apps/details?id=com.ascendapps.aaspeedometer.pro
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Post by humanshield on Jul 9, 2017 21:01:04 GMT -5
I need more torque to deal with the constant up/down hills around here. I decided to just go with a 125-150cc engine. I hope to pick one up soon. Yeah, Florida is pretty flat. There's a few bridges around connecting beaches, those are my hills. Still a pain on a stock 50. I finally got my Keihin 24mm 150cc carb installed and adjusted the needle all the way up (most fuel delivery). Man there's torque!! Yesterday I had a stock 150 carb on and it work, but bogged when the throttle opened too fast. I figured it was a velocity thing. More like too lean. After I adjusted the needle, the throttle is definitely snappy. I was pulling up the bridge today at 38 and still accelerating. I was holding 55 on US19... I'm gonna have a re entry on the speed list soon. I even got my wheelies back finally! Kinda lost them since the 49/17 gear swap but not tonight. I really wanna port match my head now and get the Airsal piston. Don't give up on your QMB! So Dex, Are you saying it was the 24mm carb that got you where you needed to be?
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