Tune Up

3 replies to this topic
  • Numskull

Posted April 05, 2006 - 06:34 PM


Well its finally 75 degrees :confused:

So I thought it would be a good time to go through the bike(first time) and see whats going on.

Ive always new there was a problem with the pilot jet (thanks to some advice from here)

I have about three problems going down. 1) my fork seal just blew, cause I left it compressed in the back of my brothers p/u for three weeks. 2) My front wheel bearings just blew out(happened fast, like 50 miles). 3) My pilot jet.

Oh my, this is gonna turn into a long post :thumbsup: Well lets forget about the first two problems as I have them taken care of.

OK lets talk jetting.My motor will cutout real bad if I try to ride with it at 1/8 throttle. From 1/4 - full throttle will rip the shit up. ( I mean you got to hold on tight). So basically Ive been riding around just not using that part of the carb for easy going.

OK heres what Ive found out, sense the guy I bought it from didn't even know it had an oil filter, It must have been the first owner who done these mods.
The cam is yz timed
yz throttle stop
air box lid gone
exhaust insert gone
Grey wire looks like its hooked up
Pilot screw was 1 3/4 turns out
Pilot jet is # 42
Main jet is # 165
starter jet is # 65

I don't have what clip the needle jet is on, cause I'm thinking its the pilot circuit. If you need the clip position, Ill go deeper. I live in Iowa, I think its about 1200ft.

My questions are:
Are these stock jets?
Did he re jet for the mods?
What size pilot jet should I go to? (read the rest first)

I started it up to do a spark plug test in the bad range, and as soon as I twisted the throttle to 1/8, the header started shooting sparks, glowing red immediately. I pulled the plug and it was brown/tan and looked good.

I'm thinking the pilot is running lean and should go up a couple numbers on the pilot jet, What do you think? :thumbsup: Thanks for any help

  • Dirt_rebel

Posted April 05, 2006 - 10:53 PM


wat's ur needle position? u mite wanna try adjust ur needle clip n see how it goes..

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  • pkcof

Posted April 06, 2006 - 06:04 PM


1/ unplug grey wire
2/ #42 sounds pretty lean especially at 1,200' - i ride between 0' ~ 3,500' and i reckon a #45 or even a #48 would be a good place to start for a pilot jet (maybe even #170 for a main also) - are you running the adj needle ? if so try the 3rd clip from the top position to begin with
3/ check for any air leaks around the intake boot, between the carb and engine and the exhaust manifold and header connection ...

good luck !

  • Numskull

Posted April 07, 2006 - 04:30 AM


thanks for your replys, Ill try #48pj and 170mj.:thumbsup:


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