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rmz jetting

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hi, just wondering what jetting i should use in my rmz. i havent ridden the bike yet, i just got it and it was running real lean after i put on a full dr-d exhaust system.

it had a 160 main, 68 starter jet and a 42 leak jet.

i didnt know much about jetting but one of the mechanics put a 178 back in which was stock and a 65 leak jet. ive seen that a few people here are using the 42.

what main jet should i go to ? im at sea level and temp is 20-30 degrees CELCIUS. not faranheit.

needle clip is in the stock position, 3rd from top.

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i put in a 170 jet and kept the 42. it still backfires but runs fine when the choke is on......

should i put the 178 in ? hope you reply quickly, hoping to go for a ride tomorrow.

i have a 175 and 178 jet.

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At 20-30C, the #170 main jet is within a good range to use. The main jet only has a significant effect at full throttle and dyno runs usually favor the leaner main for high end revs. It's a safe setting that should work well.

Try turning the fuel screw outwards to 2 - 2 1/4 turns to reduce the popping on deceleration.

James

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i havent even ridden it yet. it does it when ideling after i give it a rev. i started off at 2 turns out, then went to 2 1/4 still no difference, then 2 1/2 and still no differance.

should i go to 3 turns ? or a 45 pilot instead of 42 ?

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ooh and at the moment its about 17C. dont think that would make much difference would it ?

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Does it pop and backfire all the time?

If it does, the carburetor slide plate might be upside down -

See- http://www.pbase.com/jdjetting1/image/25566126

The plate needs the square end down. Pull the carb off the engine side and look into it. If the slide plate has the small hole near the top, it's upside down and needs to be removed and installed correctly.

Otherwise, look for air leaks and then try a #45PJ.

James

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hmm, it could be because we had that out of there. one of the mechanics at work put it back in. he said hes never seen one like that before so he probably didnt know what he was doing. ill go try it now.

ill letu know what happens.

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ok, i took it apart. the slider is in the right place.

theres this other shit that slipped out the first time i took it apart to do the jetting.

the pin that holds the float in came out and i this little silver shit fell off too. i think its the needle jet ? not sure.

anyway, i dont know if i put it on the right way.

on the needle jet thing its got like and L shape hook. look at this photo, in the photo the L shape on the needle is facing the camera. is it in the right spot or should it be facing away ?

DSC01238.jpg

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**** ! i forgot to say that the bike has a full dr-d exhaust system. when it had the stock system on it only popped a little bit but now its backfiring and popping heaps.

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shit, the square end wasnt down. i just read what u said again. that is a tricky bitch. it looks like a perfect fit with the rounded edge down. i bet alot of ppl get stuck on that one.

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Yes, the thin plate can be installed incorrectly and cause big problems. Your request to use a bigger pilot jet was one of the clues to the problem. A local rider spent 2 months struggling with this and we had it solved after a 5 minute phone discussion on what the local shop had done to the bike.

Glad to hear you found the problem. Have fun!

James

medium.jpg

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thanks heaps for the help. starts like a dream, 1 kick and im off :)

i know this is jetting, but should i check the valve clearances before i go riding ? i sort of know the guy i bought it off. it starts real good so should i worry about it just now ?

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