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Post by tsimi on Feb 15, 2016 6:13:16 GMT -5
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Post by tsimi on Feb 15, 2016 6:28:35 GMT -5
Swapped the 40/90 Jets to 38/92 and now the response at the low-/mid-range is brutal. Wheel goes up every single time and I haven't touched the clutch yet, all stock there.
The only thing I cannot figure out is my max rpm drop. I don't know why but I am reaching max rpms of 7400-7800 at the moment. At the take off it spikes up to 8000rpm and maxes out at around 7400-7800. Max speed was 68km/h. Both the rpms and top speed dropped significantly. Before, with the exact same CVT setup I had max rpms of 9400-9600 and top speed of 77-80km/h. What did I change since that?
- Installed Big Reed block with glass fiber reeds - Installed 2 stroke AU parts - Installed a different airbox sponge. - Swapped CDI from blue to red racing - Changed fuel from "regular" to "high-octane" (In Japan we have only 3 fuel types, Regular, High-Octane and Diesel)
I have the feeling that the big reed block with thick glass fiber reeds is limiting my rpms and therefore reducing my top speed. Is it really possible that the reed block can be the cause of that? I could go lighter on the rollers and also try a different torque driver setting first but if it doesn't bring anything then I might as well put back in the stock reed block, right?
What do you guys think? What could be the cause for the rpm drop?
Here something I already posted in the past.
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Post by spaz12 on Feb 15, 2016 7:31:35 GMT -5
No throttle stop. Seems odd that Yamaha would do that but I guess they figure since it's dual cable it didn't need it? Yet there is one on the Zuma...
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Post by tsimi on Feb 15, 2016 7:41:26 GMT -5
Yeah, they probably thought that the second wire will do the Job and therefore it was not necessary to build in a throttle stop.
Any idea regarding the low rpms at WOT?
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Post by birdman on Feb 15, 2016 11:03:36 GMT -5
It seems like your on the right track, maybe carbon fiber reed petals would work better.
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Post by tsimi on Feb 15, 2016 11:10:13 GMT -5
birdmanProbably yes. There is only one way to find out if the reed block is the culprit or not, I need to put back the stock reed block and test again. Or I go very light on the rollers? Maybe it is time to try the Polini OR Variator again? Stiffer torque spring? I have no real clue at the moment. Carbon reeds need to be custom made from carbon sheets since they don't sell carbon reeds for a 5BM engine. I got normal carbon reeds but they don't fit, too small. Btw. How are you? How are things?
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Post by birdman on Feb 15, 2016 13:42:49 GMT -5
Yea i would try the other reeds and see how it is. Also with your setup now i would definately think a stiffer torque spring is in order, then play with weights to fine tune it. I been good, just busy with work and replenishing all the money i spent while i was out there lol. Ill be back sooner than later. How about you and house president, and all my furry friends?
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Post by tsimi on Feb 15, 2016 18:11:32 GMT -5
Everybody is fine thanks for asking birdmanDon't be a stranger, you are anytime welcome here. How are your leathers? Still nice and shinny? Did you use them? Regarding the reed block I will try to do some small adjustments first and if those won't put up the rpms I will swap back the stock reed block.
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Post by tsimi on Feb 15, 2016 19:24:06 GMT -5
Just drove the scooter to work through regular morning traffic. Man does she drive strong! Top speed was 70km/h (43.49mph) and max. rpm was 7800-8000 I know top speed is not impressive but more than enough for city like traffic. What is very impressive is the torque and power she puts out on such low rpms. Every single time I try to take off strong the wheel goes up and imagine this is just a sport BBK with stock clutch setup. Another good thing about its current setup is the low rpms are probably better for the crank and crank bearings.
I will try to fine tune this setup and see where it goes from there.
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Jog-Mania
Feb 15, 2016 19:50:15 GMT -5
via mobile
Post by nelson on Feb 15, 2016 19:50:15 GMT -5
Your set up is definitely good for 50 mph. I had a 70 and zx pipe and it would do a bit over 50. The difference was the variator as u have already noted. I used a cheap hoca vari and made a huge difference. The rpms you are turning seem really low to me. I used the MHR overdrive pulley but I'm not real impressed with it. I was told it's for high output/rpm engines so maybe that's the reason I wasn't impressed. As for tuning your carb, man it's a pain on the jog! I stretched my engine mounts 3 inches so it's a bit easier now. They sell carbs that have one drain nut you take off and pull the main jet just fyi. Looks fun, I am only guessing but I assume a lot of people in Japan ride 2 wheels?
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Post by tsimi on Feb 15, 2016 20:55:22 GMT -5
nelsonI got used to it swapping carb jets like that and once I got the right setting I won't be touching that float bowl anymore. But you are right it is a big pain in the ass to swap jets on a Jog. Regarding the rpms there is still 1 or 2 things I want to try before swapping the reed block. Lighter rollers would be the quickest thing to do. Currently running with 25.5g. Could try the Polini OR variator with 22.8g. The thing is I always test things with same CVT setups so that I can compare so if the current CVT setup gave me 9400-9600 rpms and 80km/h top speed and now it doesn't anymore then there is something off or different and the only thing that goes through my mind is the reed block. I don't think that the new racing CDI or fuel type would reduce my max rpms. The only thing I worry is, it would suck big time if I would swap the reed block and it wouldn't fix the rpm issue.
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Post by tsimi on Feb 16, 2016 6:11:25 GMT -5
Disappointing day today. Tried to figure out the max rpm loss but it didn't work out. I tried lighten the rollers first which raised the max rpms to 9000+ and that's about it. The scooter didn't move really forward just like driving in neutral gear. Currently I can test either with 25.5g or 21g rollers I don't have anything for in between. Then I went a step further by installing the Polini OR variator with 22.8 rollers in it. Here again max rpms over 9000 but not really driving forward. Added also the Polini torque spring with that torsion control thing, that made my scoot just rev high up to 9000+ but barely moved forward. So I am nowhere with the vario tuning. Everything seems to be too light. Next I will put back in the blue CDI so that I can get that of my list. And finally it will come to the reed block I guess. Also swapped back in the 90 main jet since my spark plug showed rich condition. Now the carb tuning is complete I think.
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Post by spaz12 on Feb 16, 2016 15:18:05 GMT -5
The joys of tuning
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Post by tsimi on Feb 16, 2016 19:14:58 GMT -5
Yesterday before I called it a day I changed the torque driver setting from normal straight groove (B setting) to less angled straight groove (C setting). The C setting is suppose to give more torque and rpm so I thought I should give it a try. Today I drove to work and I must say I can't feel any difference speed- and power-wise. The max. rpms where same again somewhere around 7800. I think the top speed even decreased a bit. Will do some GPS testing on the way back home later today. Conclusion, I think the torque driver has nothing to do with it. Next is CDI swapping. I am also running out of fuel and I will use "Regular" fuel again and not "High-Octane" on my next refill see if that makes any difference. If both above make no difference I will swap back in the stock reed block. Stay tuned....
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Jog-Mania
Feb 16, 2016 20:29:32 GMT -5
via mobile
Post by nelson on Feb 16, 2016 20:29:32 GMT -5
Will it rev past 8k while on the stand? Sounds like it is shifting too early, have you tried going down on the roller weights?
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