85 jetting got me. Ughhh!

2 replies to this topic

Posted May 05, 2012 - 12:59 PM


Welp, I spent the last 4.5 to 5 hrs trying to jet this 85. With the warmer weather, been getting a little more spooge than I like and I was attempting to fight the very bad off idle bog. So I'm giving up and going with just one leaner main to trim the spooge a little.

I've done everything possible but change the needle since I don't have any to change out. I went up and down on pilots & mains & clip positions.

When I went leaner on either jet, it go worse (IT'S SUPPOSE TO GET BETTER!!)
I tried every clip position with every jet configuration I have: which is 132 to 145 mains and 35 pilot to 45. I went up and down in every different way with evry single jet.

up-up, up-down, down-up, down-down, trying all 5 positions at every one. Trying air screw from 1 turn to 4 turns at 1/8th turns at a time.

End result: 138 main, 45 pilot, clip 3rd from top, AS 1 3/4 out.

And yes been through 8 plugs to make sure I have a good clean burn and no fouling.

This is as bad as a CR125. either you get it spot on or you don't get it at all.

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  • IBeInNC

Posted May 05, 2012 - 03:07 PM


I feel your pain!!! I'm having one hell of a time getting my son's '07 dialed in. I'm going to try a 135/40 tomorrow and see how it goes.

  • JBFL

Posted May 06, 2012 - 05:29 AM


Had a gremlin cost me a buch of money this week. Sure the powervalve is working I hear the lever closing and opening. But the pin that holds the 2 blades together broke. Had this happen on a 112 motor about 6 months ago "lots of heat and runs flat on top". You'd have thought my dumbass would have realized this from before. With 17.2 to 1 compression it doesn't take long for things to go bad, cooked the crank and when the pin broke it allowed the powervalve blade to move into the bore just enough to nick the piston and rings pinching the rings. Amazing thing is compression was still at 190lbs with 2 pinched rings!

Jake would get to the 4th or 5th lap and the thing would hit almost 200 degrees, this is with his 103 race motor. Our 112 race motor is 16.5 to 1 compression and runs 160 to 170 degrees right now when it's 90 degrees here. Thankfully out of all this the new TDC 103 ported cylinder and o-ringed head are still perfect. I'd have really felt awful if they would have been damaged. Brent has more work in this 103 cylinder than the 112 because he thinks we can get close to the same performance, with some new head designs he's done.

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