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Post by oldgeek on Mar 16, 2013 5:58:18 GMT -5
Check your rear pulley, maybe its binding up and causing the belt to get all sideways..? That could explain some of the funny shifting with the stock vari as well? Ive never had this happen either... I did check the pulley out, It seems to be fine. I just had it apart to clean it up and install a new spring, and one of the torque spring bearing bases you recommend.  It must have been a fluke, of possibly something got into one of the CVT vent holes, who knows! We are expecting great weather for the next few days, so maybe I can get some of this stuff worked out today. I wont get anything done Sunday, I have to drive to Spartanburg and back, so that is at least 8 hours round trip. |
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Post by oldgeek on Mar 16, 2013 16:12:14 GMT -5
I made some more changes to everything today. I finally arrived at following setup. Hoca variator with 4.5G sliders Stock clutch with stock springs, 1000 RPM contra spring with the bearing spring base 80 main jet jet needle 1 notch lower I think the CVT setup is pretty good. The only problem is with the launch, it really sucks. I am thinking stronger clutch springs may help with that. I have some 2000 RPM springs I can swap in when I can get access to my friends vice. The carb is still rich just off of idle, but once it hits around 3K - 4K it pulls nearly hard enough to  Can anyone tell me if a smaller pilot jet would help me out? I really don't have the dough to get a new, better carb and jets at the moment. I rode around all afternoon, the temp got up to 77, but the wind near the beach is brisk. We have a car show here this weekend, so traffic was pretty bad all over, but man there are some nice cars here. |
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Post by 90GTVert on Mar 16, 2013 17:59:59 GMT -5
Stiffer clutch springs will prob make a big difference. Smaller pilot jet may be needed, but I'd wait till you install the springs. May not have the same issues when it's not struggling off idle.
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Post by moofus02 on Mar 16, 2013 21:04:29 GMT -5
Tonight I put the front plastics on so I would have a headlight, and then I went for a ride. All was well until on the way home, at WOT if felt like the belt slipped bad. I quickly backed off, and everything seemed to be ok. I was near the house with no stops till I pulled up to my shed. Right before I stopped I heard something in the CVT sound a little off. I pulled the cover and found the belt had flipped over, and was riding upside down! What the hell could have caused that? The bando belt (788 17 28) still looks like new. Had that happen on a Rupp 440 magnum competition sled. No idlers on the slidrails and my brother took iton a run down a long hardpacked road, the hyfax got hot and started melting and track got tight. Instead of stopping or running into some snow to cool it off he just gave it more gas because it was mine and not his. When I got it back the belt was flipped with fuzz coming out of it and you could turn it inside out with one hand. The clutch was grooved and blue from heat along with the torque converter but the tc was cracked. motor made power spun clutch on belt and spun belt on torque converter and made everything hot. He was lucky I didn't kill him but even luckier it didn't toss the belt cause that sled had no guards and the belt was in open about 4 inches from your left hand. Weird stuff happens Sent from my HTC Evo 3D using proboards |
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Post by oldgeek on Mar 27, 2013 20:07:29 GMT -5
Stiffer clutch springs will prob make a big difference. Smaller pilot jet may be needed, but I'd wait till you install the springs. May not have the same issues when it's not struggling off idle. Finally got the springs changed out and you were right, it is much better with the 2000 RPM springs. There is still a little stutter when just getting into the gas (1/4 throttle) but at 3300 RPM or so it pulls like mad. I really would like to get it 100% , but I could live with it as is. Should I try 2500 RPM springs or move on to the pilot jet? So my first ride this evening after getting the new clutch setup installed was short. I got about 3 miles from the house and noticed a roar coming from the CVT like a bad bearing. Fearing the worst I babied it back to the house, and pulled the CVT cover to find ball bearings inside the cover WTH! now? At first I thought the balls came from the TQ spring base, but it looked fine. It turned out to be the clutch shaft bearing in the CVT cover.  I whipped out the blind bearing puller I picked up from HF, and pulled the outer race out, cause that all that was left. Luckly I had a spare bearing to put in. I got it all back together, and went back out for a test ride. Top speed on this run was 53.24 mph @ about 10380 RPM. Not sure what the cruising speed is cause I keep the GPS in my pocket, but it seems to like about 9300 rpm's @ 3/4 throttle. |
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Post by Corrosion on Mar 27, 2013 20:37:57 GMT -5
Be glad you have that Extra Bearing. I'd kill for it. I wizzed out 2 cover bearings so far. Yamaha must think there not necessary. At least now I know what the vibration is, and I keep a couple on hand.
1/4 makes me think, hopefully pilot adjustment its easier. But more probably needle position.
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Post by ʇwiƨtɘdburnout on Mar 27, 2013 21:37:25 GMT -5
I think the dishwasher and oven thing was funny as hell! I read these last 11 pages and you guys are speaking total Chinese, lol! scavengers, .0001 's this and .00002's that, engagements, torsions. My freakin head is spinning.  |
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Post by oldgeek on Mar 28, 2013 6:20:15 GMT -5
Be glad you have that Extra Bearing. I'd kill for it. I wizzed out 2 cover bearings so far. Yamaha must think there not necessary. At least now I know what the vibration is, and I keep a couple on hand. 1/4 makes me think, hopefully pilot adjustment its easier. But more probably needle position. I will probably try the pilot if I can find the right one for this carb. I have previously tried other main jets, and different needle positions, but I just cant seem to get it worked out. I may need to go back and try the needle again, since I finally have the CVT dialed in pretty good. I think the dishwasher and oven thing was funny as hell! I read these last 11 pages and you guys are speaking total Chinese, lol! scavengers, .0001 's this and .00002's that, engagements, torsions. My freakin head is spinning. I did not realize the water was so deep when I jumped into this project. LoL! But thankfully there has been plenty of helpful people along the way. I should have gained a little more experience first upgrading a RUNNING scooter, by installing a BBK kit, jetting, and then tuning the CVT. But I didnt, and it all worked out pretty good anyway. I hope there is a 90+ in my future.  |
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Post by 90GTVert on Mar 28, 2013 11:42:56 GMT -5
I'd try the needle first if idle mix has no effect.
If you do end up wanting later clutch engagement, you can lighten the shoes a little if you wish. Only prob is that you can't just add weight back so easy as installing different springs. Could prob use 1500 or 1000RPM springs though if you did go too far. Doesn't take a whole lot to make a difference.
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Post by oldgeek on Mar 31, 2013 21:16:54 GMT -5
Does anyone know what # jet needle is typically in a stock mikuni carb? Or possibly the series it uses? I need a needle to help out with the rich mix I have from about just off idle to 1/2 throttle.
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Post by 190mech on Apr 1, 2013 20:03:35 GMT -5
Dude!Leave it rich at part throttle!!More pistons are fried at low throttle settings than wide open..
When a 70cc piped motor is tied to a stock sized carb,things get reaaal hot at part throttle.Be happy with the rich blubber and crack the throttle WFO to make you and the engine happy!
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Post by oldgeek on Apr 1, 2013 20:50:26 GMT -5
Dude!Leave it rich at part throttle!!More pistons are fried at low throttle settings than wide open.. When a 70cc piped motor is tied to a stock sized carb,things get reaaal hot at part throttle.Be happy with the rich blubber and crack the throttle WFO to make you and the engine happy! Ok, Ill do it! LoL! But I gotta have some relief from dead stop, the 1&2 foot push offs are getting old! I currently have 1000 RPM clutch springs, what do you think about 2000 RPM or higher? |
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Post by 190mech on Apr 2, 2013 4:31:41 GMT -5
That'll help,I lightened my clutch shoes too..
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Post by oldgeek on Apr 2, 2013 21:32:01 GMT -5
I worked on the CVT today, trying all kinds of stuff. All I really wanted to do is move the 2K clutch springs from one clutch to the one I have been using that has a 1K contra spring in it. However since I didn't have a vice handy to get the big clutch nut off, and my friends vice was not available, I ended up just putting the clutch with the 2k clutch springs, and the 1.5K contra spring on the scooter. After trying a bunch of different weights, and different thickness washers in the variator, I ended up with 6G sliders and a .20mm washer at the fixed half of the pulley. Overall this setup is not too bad. The 2K clutch springs later engagement definitely helped the low end out, but I think the 1.5K contra spring is just too much. The 6G sliders seem to get the CVT into high gear too soon, and it sorta sticks there a bit, while the 5.5G sliders let it rev to high. Anyway, me, my brother, and two of our friends had a blast taking turns riding it up and down a road in the industrial park. Top speed with this setup was 49.44 @ around 10200RPM. Short video of yours truly doing a pass.  |
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Post by teddy554 on Apr 2, 2013 22:25:40 GMT -5
Nice seems everything is coming together
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