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Post by phatboy on May 14, 2016 14:17:03 GMT -5
Actually the 6.5g rollers I talked about were a combination of three 6g and three 7g. So I got the idea to take three 6g rollers so I mixed with three 5.5g for average 5.75g, and it reaches full speed while having almost the same performance so I am pretty sure it is the narrower/worn 5.5g rollers not pushing out the variator enough.
I can order new 5.5g rollers but clearly the problem is the variator needs to be closer together.
I have seen others shaving the boss down 1mm or so, but I wonder, it seems like it would be hard to get a totally flat surface using a grinder, how important is it to get the surface totally flat?
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Post by phatboy on May 11, 2016 22:36:27 GMT -5
I'm trying different rollers, I went 5.5g and got better acceleration but with a loss of about 2-3 mph on the top end. Some say this isn't supposed to happen, but it did.
That was when I took the rollers out and measured with a caliper, a 6.5g roller was actually 0.12mm over the spec diameter. A 5.5g roller measured 0.16mm under.
Is there a +/- tolerance for roller diameters somewhere? I have seached and not been able to find anything.
The difference is only 0.28 mm between these two sets and it does not seem like much, but could this really make the difference in a few mph, or is it just the lighter rollers doing that?
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Post by phatboy on May 11, 2016 19:00:40 GMT -5
OK, got the wider belt today. It was good for about 3 mph on the top end and no loss of power on the bottom end.
The weird thing is that the ink on the variator has barely moved. It is 4mm still, so the belt is only riding 1mm higher on the top end than a stock width belt. It is surprising that 1mm can make that much of a difference. I am at a loss to explain it.
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Post by phatboy on May 9, 2016 15:21:20 GMT -5
The china variator that broke on me was oversized, and comparing with stock it also had a flatter ramp angle, so belt must have been higher up. I got about 5 mph more out of it. I am starting to wonder if this is the right approach though. With this setup the china belt shreded after 50 miles, maybe it was riding too high on the variator and rubbing on the inside of the case. The wider belt I got on order is a Bando, if that shreds I will look into regearing. Also been running with the CVT cover off while tuning, is that a bad idea? JerryScript I checked the gear ratio by spinning the clutch 100 times and got about 7.5 revolutions of the rear wheel, so final drive ratio is about 13.3:1. Based on a thread I found, other 49cc scoots seem to have a final drive about 11:1, so my bike does seem to have pretty deep gears on it, probably would benefit from taller gears. When I get a chance I will open it up and look at what it really has. rockynv the clutch does not seem to be sticky, however I am not sure of the variator face, I do see a definite darker area where the belt runs 5mm from the top of the variator, not sure if that means wear or not, or if the face should be cleaned (or it can be) I will post a pic when I get a chance. |
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Post by phatboy on May 7, 2016 22:17:16 GMT -5
I got a belt 12mm longer than stock and saw absolutely no difference in top end. I marked the variator with ink, and measured. its 5mm actually (8mm was a guess.) Heavier rollers don't make a difference in how much ink is left. With this setup the scooter is topping about 40-42, too slow.
I think the answer is a wider belt, not longer, to make it ride higher on the variator. I found a belt 1.7mm wider than stock and about the same length. I've ordered it and will report results.
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Post by phatboy on May 4, 2016 14:53:49 GMT -5
Does your kit include a performance cam too? In my case the BBK alone wasn't as dramatic as I hoped, In my case the addition of an A9 cam really helped the BBK along. YMMV of course.
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Post by phatboy on May 4, 2016 2:39:21 GMT -5
Hmm, well I need to check that, I had no idea there was a CVT air filter. Overheating in there could've been my problem the whole time. I suspected it might be hot in there, by the way it acted up after hill climbs. Also I saw some smoke coming out after the belt failure.
The variator was stuck closed but I was able to free it from the boss by hand so it wasn't welded to it, there is a chance it stuck open as well at one time or another. I think the belt didn't fail suddenly, the last time I started the bike the starter sounded weird. There must have been belt fragments in the starter gear already.
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Post by phatboy on May 3, 2016 4:15:50 GMT -5
I need to go to stock variator for a while (a new china variator I bought fried itself after just 50 miles). The old variator worked fine, but the problem with it (and the reason I tried to replace it) is that no matter what I did I could not get the belt to ride all the way up on it. Could never get that last 8 mm of unused travel on the edge of the variator.
I was thinking, what if I try a belt that is just a little longer, say 10-15mm longer, with same width and angle. Assuming the belt is not so much longer that it would rub, could the extra length make the belt ride up the variator higher? Or would it make things worse, like, ride the same on the variator but ride up the clutch more instead?
I don't see much talk about longer belts, has anyone tried it and how did it work? Or is this really just a bad idea? Or is the answer a shorter belt instead?
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Post by phatboy on May 2, 2016 16:13:44 GMT -5
OK, so definitely getting a new variator, not going to try to lube this one.
But I still wonder if the stuck variator could have shredded the belt, or if there was another reason for that.
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Post by phatboy on May 2, 2016 5:00:12 GMT -5
My scooter belt shredded. When I got it taken apart I found my variator was stuck in the closed position (high gear). It is binding on the boss. No belt fragments in the variator, the boss shows score marks, I think the variator was just crap. Correct me if I'm wrong, but my understanding is you don't lube the boss, nor should you ever need to. So if true I will be replacing the variator. It was a cheap china variator, lesson learned and I will get something better.
Thing is, it seemed fine otherwise, other than the slow takeoff. I just checked the belt recently and it seemed OK, initially some dust at 15 miles but didn't look worse at 30 miles so I stopped checking. The belt only had about 50 miles on it total. It was a china belt, but still. 50 miles?
So ... what happened here?
Defective variator that caused early failure of the belt?
Or, this defect in the variator should have no siginificant effect on the belt's life, and the belt was also just plain defective?
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Post by phatboy on Apr 18, 2016 16:22:30 GMT -5
new pod filter, thin screw clamp (took two small thin ones and threaded them together), carb cleaning, new fuel lines, tank cleaning, new flter and rejet later the bike is running pretty good. More power too, this hill I could only climb at 32 before, it climbed at 35 today. Definitely it was too lean before, as all those bogging problems are pretty much gone.
Weird thing, though, I seem to have lost about 2 mph on the top end, going down this straight road with a slight decline I hit 48 with the old setup but today just 46, despite the bike running better overall. Is it possible that running lean could give more power on the top end, but less at other RPM ranges?
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Post by phatboy on Apr 17, 2016 14:28:11 GMT -5
Before you order tires I'd measure the clearance from your current tires to get an idea for the biggest/tallest you can get. If you post the clearances and the current size of your tires then I'm sure some here can make recommendations of a bigger size that will probably still fit. I got some Michelin 130/  -10 on mine, and clearances are pretty tight but they fit fine. Plus I found these are the biggest/tallest 10s you can find easily. I'm not sure I would say it handles better but it raises the scooter which is important as I am taller than average. Plus I'm sure it gives a better top end and taller tires are easier than a regear. They were not very expensive either, think I paid $35/shipped each from eBay. You can get taller/wider than 130/ of course but I had a lot more trouble finding these, and what I found were more expensive. |
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Post by phatboy on Apr 15, 2016 15:59:26 GMT -5
Today I found the manual petcock was not all the way open, and although flow upstream of the filter was file, I think there was just enough of a restriction in the filter to limit the flow. When opened all the way it is not exactly free flowing through the filter, defintely there is a restriction, but so far flow looks adequate.
I did clean out the tank today anyway (swished out with new fuel and drained a few times, not sure what else I can really do), and installed the old 150 micron upstream as a pre filter, we will see how that goes. Next step is to clean the carb completely, and hope I am done with the fuel system for a while.
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Post by phatboy on Apr 14, 2016 13:28:36 GMT -5
The tube above the filter flows fine, new petcock is manual, for a motorcycle (on/off/reserve switch) I probably should have mentioned that  My old filter was 150 micron and it flowed fine, but I think it passed too much junk, I had stuff in my float bowl and the float needle would stick open. However the filter never clogged. I guess there could be lots of finer particles in my fuel but really could it both be invisible and clog so quickly that the bike won't run for more than a minute? |
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Post by phatboy on Apr 14, 2016 0:42:36 GMT -5
I just changed out my petcock, clear fuel lines, and both the fuel filter in the petcock, and a clear inline fuel filter, the kind with the sintered bronze screen. I used (what I thought were) quality parts. So I put it all together yesterday, but it was raining so did not test ride until today. The scooter started up fine but died after two blocks.
In that two blocks, it completely drained the gas in the fuel line downstream of the fuel filter. The flow out of the new fuel filter was like a drop at a time, too slow to keep it running. Flow above the filter is fine, and it is installed in the right flow direction according to the arrow on it.
I have had problems in the past with debris in the fuel system but the gas in the lines and the filter looks totally clean, I don't see any debris at all. It could be clogged already, I suppose, but can a fuel filter really clog up instantly like that when the fuel otherwise looks clean, or do you think I just got a bad filter?
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-10 on mine, and clearances are pretty tight but they fit fine. Plus I found these are the biggest/tallest 10s you can find easily. I'm not sure I would say it handles better but it raises the scooter which is important as I am taller than average. Plus I'm sure it gives a better top end and taller tires are easier than a regear.