Got my Pro X jets a couple days ago and finally pulled them out of the bags. NOT HAPPY!!!! They are not even close to the size of Mikuni. A 200 Pro X jet is about a 100 Mikuni Jet. Only one I have to work with is the 150 Mikuni I bought. Now I understand why the lowest they sell is a 110...any lower and it would be a closed hole. I am now assuming I have to buy pro x jets in the upper 200's and low 300's to maybe get a match around 160-200 Mikuni.

 

Put the 150 Mikuni jet in and now it is getting way to much gas...doesn't even want to rev up. How on earth is going from a 132.5 (way too lean) to a 150 (way to rich). According to that theory I need a 140. Can't believe that only going up one would fix everything!!!! Going to keep messing with it. Anybody got any ideas on what is going on b/c I can't wrap my head around it? Think I might put the 132.5 back in and see if it goes back to being lean. Did notice that my slide on the carb wasn't down the whole way....adjusted wrong. Never touched it, but somehow there was a gap...wasn't shutting. Did fix it...not sure if that has anything to do with it.

 

UPDATE: Realized that my choke was on (too much gas of course). I have two quadracers, one choke is up the other is down, got confused. Well it was actually running on choke b/c all this messing around tore my intake, HUGE MASSIVE air leak...almost blew it up with the choke off. Carb barely fit b/c it is a standard intake for a 34mm carb, however I have a 38mm on it. Ordered an NOS 38mm intake for it...not cheap and not easy to come by. Should fix my air leak and hopefully my 150 jet is accurate.

 

Glad to see you are getting it right. Sorry about those jet sizes, I guess they are just closer to Keihein? Good to see guys keeping the old racers alive!

 

Got the new intake on...Love it!!!! Started right up with no problems, great idle, still breaking her in. I've done a couple plug chops on it and got a nice blackish brown plug...so maybe I lucked out with the 150 main jet and if that is so then I can go back down to my 132.5 and get my thunder power jet dialed in. She is like a F#$king rocket. I have had 4 Quadracers (87-88-90-92) and this 87 is where it is at...nothing compared to my 92 right now. Pushing 171 psi in the jug and got air ramming down it's throat. Going to be a gas hog but don't care as long as the front end lifts up and I keep eating everybody else on the trail. Still running pump gas in it...haven't even got the cam II/VP in her yet. DON'T KNOW WHY EVERYBODY DOESN'T OWN ONE!!!!!

 

Here's the verdict:
150 main is good, air screw set at 2 turns out, and she is rippin'. Forget what the pilot is but didn't have to change it or the metering rod clip (still set in middle). Used the 2 Stroke Jetting Guide from Dirt Riders Magazine which def helped me jet it pretty quick...got lucky with the 150 main. Perfect looking plug after 2 chops. The whole throttle band hits hard in every gear. Back in the woods as of today.

 

are you a subscriber?

 

Nope...not a subscriber.

Have to put this in there for everybody. Still don't know what's up with my jetting!!!!!!!!!! Ran it a little more and for some reason it is still seems to lean. Put in a new plug and it has a mocha brown on the porcelain and the electrode, with very little change on the ring (just a little oil). Have a little oil at the tip of the silencer with the perfect amount of smoke, not too much not too little. Feels great and tons of power, not choking or hesitating at all. When it gets really warmed up the rev doesn't want to come down, maybe need to knock the idle down when it warms up. Seems like I have both lean and rich problems. Maybe rich on the 1/8 to 1/2 throttle and lean on the 1/2 to full throttle. Maybe I just need a bigger main jet. Ordered more, should be here next week. Tried to get pic of plug on here but won't let me, not enough posts yet.

 

your 87 sounds like it is setup VERY similar to my 88. I don't know for sure the size of my carb but I am also running a straight UNI filter with aggressive port work and full FMF exhaust. If I get a chance, I will pull my carb and take a look at the jet size for you on Friday. That is the soonest I can look as I keep all 8 of my quads locked up tight in a storage unit as I have no garage. I coach Youth football after work but I work for an Indian casino so Friday is Native American day and I get the day off

I will let you know though.

 

Problem is nobody else runs a VM38...most just run stock carb (TM34 slide). Stock carb jet is around 210-260...which doesn't help me. Did put in a 162.5 jet today and it seems to be running great, plug appears to burning right?????, but still has oil on the bottom plug ring...might be too rich on bottom end now but may be able to lean it out with air screw. Happy to see that since before it was nothing...too lean. Still poking around with the jets but I know I am def getting close.