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Post by hmin7186 on Nov 5, 2004 15:43:43 GMT -5
hey guys i've been trying to do some mod on my ruckus and i'm having problems... i've done drive mod and installed POD type filter..
i'm trying to jet my carb but i'm not doing a good job of it.. i've tried 80, 85 and 90 main jet.. and for all of them when i go to full throttle i hear detonation.. 80 seems to work the best at up to 90% of throttle but at full throttle it detonates..
i'm wondering why this happens... is it too lean at fulll throttle? should i go ahead and try 95 and 100 main jet? but i think that's is too much since i have stock exhaust and cdi...
someone asked me if i have aftermarket cdi box.. but i don't and i'm thinking if i put an aftermarket cdi box in it, it would advance my timing and make the detonations worse?
please help me out here... if anyone else has done the same mod please let me know what you did.. and others that have great knowledge in this matter please help! i'm quite lost.. thanks
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Post by Vishnuk on Nov 5, 2004 19:36:16 GMT -5
Check your plug, if its choclate brown then your spot on, black and oily too rich, charred and white then your too lean and will melt something. You could probably handle a 95 jet.
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Post by abe on Nov 9, 2004 5:35:47 GMT -5
A CDI booster may not make it faster but what it will do is keep you from hitting the RPM limiter. I don't think you have detonation. A tach would help you learn what's happening.
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Post by zoomerman on Nov 9, 2004 9:48:19 GMT -5
Hmin7186,
What drive mods have you done ?
Perhaps your rollerweights are too light and what you're hearing at full throttle is the rev-limiter cutting in ? Mine did that with rollerweights that were too light. At half speed I'd floor it and hear the same sound you hear when you floor it down a hill at full speed.
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Post by hmin7186 on Nov 9, 2004 11:14:23 GMT -5
how does it sound when you hit the rpm limiter?
for me i don't think it's the sound when it hits the rpm limiter because it happens at low speed too.. anywhere from 15mph and up when i hit the full throttle it sounds like pinging... something metallic rattling in the engine...
anyway next week i will spend sometime to try to jet it properly again.. and see how it goes..i need to shim the needle...
i should probably get the CDI booster too... but it's so expensive..
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Post by zoomerman on Nov 9, 2004 11:40:35 GMT -5
The rev-limiter makes your engine sound like it's sick, like it's only firing half as much as it should, like a two cylinder engine running on one cyclinder. (run your scoot full-out on the center-stand and you'll hear it) If your roller weights have an average weight less than 6 grams it may be revving too high, even at low speeds, and causing the rev-limiter to come on. But that shouldn't sound metallic or ping-like, so the problem is most likely not related to your rollerweights or rev-limiter. I wish I could help more.  |
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Post by Vishnuk on Nov 9, 2004 19:12:01 GMT -5
My engine pinged under load when I had an air leak at my intake bellow. Too much air? Just a thought...
More tales of carb tuning; I really really really hate this carburetor. I have a .75 mm shim (another home-made shim...I upgraded from the one made from a beer bottle cap to a shim made from a pair of cheap scissors that I cut up) in there and ran the gamut today from 80 to 95 main jet and back all with tape on, off, and a plethora of other combos. I'll give a quick run-down of my results. 80 jet, holy hell crap. Didn't even make it out of the driveway. 85, same results, made it out of the driveway though. 90, accelerates fine until 15 mph and cuts in and out, continues this behavior until about 30 mph where it settles down with a max speed of 36. 95 jet, no bogging but runs into the engine control nazi pretty violently at 36 mph and my plug had traces of oil forming around the metal bit that has threads. The white bit was starting to turn amber at the back where the electrode thingy pops up at. I'm thinking I should run a 92/3 main with my airbox cut open. I'm running a 90 and a sliver of tape on the intake.
It's probably worth it to just buy the CDI so I can go get a non-cv type carb. On the plus side, I'm really damn quick at taking stuff apart and putting them back together now. ;D
If I keep failing, I'll go back to stock. Really makes me want to cry...
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Post by Dandy Dan on Nov 11, 2004 10:56:34 GMT -5
I was running a 95 but i dropped er to an 85 today. The 95 runs nice up to 30 mph but the top end sux. You need to run a lower jet and shim the needle to get max power at all speeds. The 85 runs like crap to 30mph. I have to use my hand to cover the air intake until its up to 30. Then it sings and heads up to around 39. I can't say for sure cuz i've only been out on one quick test run. Now i'm trying to whip up a shim so shes runs nice off the line too.
Just cuz it runs like crap at lower speeds doesn't mean your jet is wrong. Try it out at higher speeds and if it works well there just shim to get the bottom/mid range right.
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Post by Ruckass on Nov 11, 2004 11:38:34 GMT -5
I looked all over town for an appropriate shim . Finally an elctronics shop carried a small enough washer. I would say try one of them and bring the vacuum chamber with you to try it out. I found one that was so close that it just needed a little bit of sanding around the edges to make it fit. The guy just gave me 5 for free!
Ruckass
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Post by Dandy Dan on Nov 11, 2004 13:53:38 GMT -5
Well i finished with my shimming. I put two small shims in for a total of about 1.8mm and .....well.... it still runs too lean (shims = beer caps cut out). I know its lean cuz when i cover part of the air intake with my hand its quicker off the line. You can't really shim much more than 1.8mm cuz you have to shave a bit of plastic off the bottom of the piece that holds the needle in there and you can't take off much more than i did.
With all that said, an 85 jet and a shim might work well for someone else. I have my airbox open about as wide as possible and I have a noticably higher flowing airfilter from Canadian Tire. Additionally the temp. these days is hovering around 0 degrees (32 F). So If any of these are different for you then you could be golden.
I'm not sure what to do. I could put the heavier airfilter back in....Or perhaps shorten the spring. Does anyone know if shortening the spring would do the trick and if so how much?
An 85 jet is great on the top end, i'm up near 40. its just hard to get the midrange good.
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Post by Vishnuk on Nov 11, 2004 15:43:22 GMT -5
I'm having that same difficulty. The 85 jet feels really dangerous to me to try and wait for the engine speed to catch up. It surges and skips and generally misbehaves. I wouldn't trust it in traffic. I need to find a proper sized shim to go with the jets. I'm thinking that a 95 jet is fine as long as you don't shim the needle and don't go top speed on the thing. If your a 30mph cruiser, that probably works great...its just balancing the top and mid thats a real "edit profanity".
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Post by Ruckass on Nov 11, 2004 16:36:13 GMT -5
I'm running a 85 jet and a .5 mm thick shim it runs great at the high end (41 mph )a little fidgety off the line. I'm gonna try taping off some of the filter.
Ruckass
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Post by abe on Dec 4, 2004 16:38:50 GMT -5
From what I'm hearing we need to come up with a richer
pilot jet for you guys.
Has anyone settled on a main jet/shim combo and been happy?
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skelly
Junior Ruckster
Posts: 92
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Post by skelly on Jan 7, 2005 1:19:36 GMT -5
Not sure if this relates at all but I found that my kick starter was slightly rubbing inside the sidecase. I put a coupe dabs of grease on it and it went away for a bit...
It sounded like what you are desribing... *shrugs*
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