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Post by tsimi on Jan 14, 2016 9:12:38 GMT -5
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Post by tsimi on Jan 15, 2016 3:10:20 GMT -5
Yesterday I installed the longer belt and just quickly started the engine to see if it runs and to see how far the belt sits on the rear pulley. I couldn't see any difference yesterday and so I closed the CVT cover.
Today I went to work with the Scooter, I have a bit stiffer clutch springs in it at the moment so I should get later clutch engagement but somehow this is gone. It starts slow and picks up speed somehow like starting in 2nd gear. (Back to that issue again)
Just now I opened the CVT cover again to check where the belt sits and realized that the belt is a bit loose. Loose in sense as if you squeeze the belt together it is more loose then with the shorter belt.
My question now, is it possible that the rear torque spring (currently stock) has not enough force to push the longer belt all the way out on the rear pulley and therefore giving it too much slack? (when the Scooter stands still and engine is not moving)
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Post by oldgeek on Jan 15, 2016 6:15:03 GMT -5
I would definitely try a stiffer contra spring. When you delay engagement of the clutch, the pulleys often start moving the belt to a higher gear before the clutch even engages.
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Post by spaz12 on Jan 15, 2016 6:18:14 GMT -5
Take some pictures for us. I want to say that wouldn't be the case because you would have noticed this before the new belt. I could be wrong, but I don't think so. Did you somehow get an OR belt?
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Post by tsimi on Jan 15, 2016 6:33:55 GMT -5
Hmmm...
The belt is just a bit longer. I don't know if you can count that as on OR belt.
Stock belt, according to the maker is 796mm the new belt is 803.5mm only 7.5mm longer.
I haven't put back the previous belt but I will do that tomorrow to see if it really is belt related or just a different problem that coincidentally shows up now. I just know that the belt as it is now has too much slack in it.
I also could try to add an additional spacer into the variator boss to get the belt down at the front and therefore stretch the belt a bit.
Guess it will be another CVT tuning weekend, yeah! Need to install the torque driver as well but step by step one after the other to see what pros and cons show up.
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Post by spaz12 on Jan 15, 2016 6:46:14 GMT -5
I'm no belt expert (except maybe oem Yamaha lol), but that sounds a lot longer. I'm no expert though.  |
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Post by tsimi on Jan 15, 2016 6:51:11 GMT -5
Yeah, me neither. I have a hard time to find out what sizes all the belts are because those  don't write the sizes on the belt itself. I will try to measure tomorrow my Kevlar belt, this new belt and the stock Yamaha belt let's see... I wanted to have a long belt so that I can get to the most outer edge of the rear pulley similar like Brent does in his Variator Testing videos (Malossi Multivar). If anyone knows the length of a stock belt for a Jog or Vino please come forth and enlighten us. |
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Post by tsimi on Jan 16, 2016 6:48:43 GMT -5
Today I went and opened that beast Jogs CVT to see what such a monster needs to get such power on the road. And here some Info; - Variator (not OR) but shaved inner area and steep angles. - Only 3 roller weights! Probably 7g (Total: 21g) - very light and no cooling fins front face - The most stiff torque spring I have ever felt when pulling the rear pulley apart. - white clutch springs (no idea how stiff though) - stock clutch bell and clutch shoes - after market torque driver with straight grooves - same long belt as I have right now. (KN企画 7020-L-SS | 803.5mm / 16.6mm) The drive boss was also a lot thicker then the stock Yamaha. What I did today is add an additional 1mm washer to the Variator to see if the belt would go out and it did. I have now a "almost" perfect belt alignment on the rear. The problem is I sacrifice a lot top speed. Before max was 69km/h now I can get maybe 60km/h at nearly 10000rpm! Which is not so good for the stock crank. Tomorrow I will do some more intensive CVT tuning, let's just hope the weather stays nice till I am done. Weather forecast says rain in the evening tomorrow.  One thing I know now is, you cannot have a very good take off and very good top speed with a stock Variator, Belt and Torque driver. You can have average of both or one or the other but just not both. So staying with a stock CVT setup is not an option for me. |
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Post by niz76 on Jan 16, 2016 12:04:41 GMT -5
I see you have found the limitations of the stock vari! A long time ago after really studying the stock vari and it's limitations, I was successful at gaining a few mph by filing the stock ramps as they just "dead end" and don't really allow the rollers to travel far enough before hitting "the walls" of the ramps. After that, I was looking for more and realized the reason the expensive OR vari's work is because of their extended "rails" and better designed ramps that don't just dead end into a wall like the stock one. The ramps slope up and allow the rollers to just keep going... An aftermarket Hoca vari solves that problem but is still limited because of it's short "rails" that don't really allow the ramp plate to travel as far as it needs to, to cover the length of the whole drive boss and get the belt out to the very edge. I badly wanted an OR vari but didn't want to spend the $$. I should not have been surprised that Brent had already identified these shortcomings and devised a "mod" to get around them! Now that my Hoca vari is modded to be like an OR and also has the faces shaved, I have best spacing for the belt to get down deep between the faces for best launch, and also extended guide rails so that the ramp plate can fully "open" for best top speed also! This mod gives the ol' 'give and take' a big kick in the nuts and lets you have both great takeoff and top speeds! Of course, you could just purchase an OR vari ($$$.$$) and these mods are already done for you  Here's the writeup: 49ccscoot.proboards.com/thread/1227/homemade-overrange-variator |
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Post by tsimi on Jan 17, 2016 4:15:30 GMT -5
More CVT tuning done today. Installed the torque driver and swapped the Variator to my After market one. Previous I had some sort of lag in speed around 30-40 km/h with the after market vario, that time spaz12 said that it could be the stock torque driver that has an angled groove and he was right since I installed the after market torque driver that lag is gone. Now I need to fine tune the CVT and see how I can get those rpms up a bit, because the after market Variator has around 1000-1500rpm less compare to the stock vario. Top speed reached with different setups were; Long Belt + Stock Vario + additional Washer = 60km/h at max 10000rpm Kevlar Belt + Stock Vario = 69km/h at max 9600rpm Long Belt + After Market Vario = 77km/h at max 8200rpm And here some Images of the belt alignment with different CVT setups. Current setup      |
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Post by spaz12 on Jan 17, 2016 4:46:58 GMT -5
Try some lighter weights to get those rpm's up.
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Post by tsimi on Jan 17, 2016 4:51:41 GMT -5
That is what I also had in mind since it is the easiest thing to do.
I also have one more straight groove setting on that new torque driver. According to the manual it should raise the rpms. But that will be a setting for later if all else fails.
At least I finally got a decent belt position.
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Post by spaz12 on Jan 17, 2016 4:56:29 GMT -5
yeah, that's around 48 mph (easier for me to understand) and I think you should be getting a bit faster. Then again I don't know what your gear ratio is, so maybe that's really good?
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Post by tsimi on Jan 17, 2016 5:01:26 GMT -5
Gear ratio is 11.75:1 I think. 11 turns and a bit more.
48mph is fast enough for me, what I want is brutal, wheelie take off power. Fast acceleration from 0-48mph If I can get that then I reached my goal. I think to get more top speed then I have right now I might need a real OR Variator like a Malossi Multivar, Polini Evo or Stage6 Variator with real Overrange size. The one I have right now is just an optimized stock size Variator with a slight larger diameter but same size roller weights (15x12)
Overrange Varios have 16x13 or better 19x15.5 rollers which makes sense.
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Post by tsimi on Jan 17, 2016 5:17:02 GMT -5
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Here's the writeup:
