swag Posted July 25, 2006 Report Share Posted July 25, 2006 hey guys ok here is my problem. the right side plug is perfect coffee color after a good hard ride. the left side is drooling black. i have:k&n, 38mm kehin carb (flat slide), moto fast spacer plate and adapter, mod quad cool head (21cc domes) running 91 ot, rt side .090" and lt side .080" over fresh bore from trusted shop, pistons have .004" clearance, rings .003" clearance, fmf gold series pipes and silencers, rickey stator plate at +4, 180 psi compression cold with throttle wide open 500 ft above sea level, medium port job, and crappy stock reeds one side new (rt side) one three months old. I am running motul full synthetic 50:1 When i am below half throttle the lt side barely hits at all and as soon as it gets on the pipes it hits great. oh yeah i am running ngk br8es plugs. I have checked both reed cages and the both will hold water with a few drips after 3-4 seconds. i am at wits end here. i have puled my jugs and kind of made up my own test that may or may not be valid. heres what i did. i taped over each transfer and intake and exaust port filled them with water and measured what i dumped out into a graduated cylinder that will measure .5 ml all are within 1ml between the rt and lt jugs. they look exactly the same and i have measured as closely as i could with an inside bore gage and got them all within .100". the one thing that i could not get exactly right is my boost/bust port but it is within .180" and like i said it holds as the same amount of water as the good side i realize the water method may be a bit backyardish but i think it should get me close. any way i know i am probably overlooking something really simple but i am sure you guys know what it like to frig with something for so long that you start chasing you tail so to speak. i also have a lightened flywheel not aftermarket i just put it on my lathe and shaved some off. and it has new crank seals too and yes i put sealer on the ribs. any help at all would be very much apprciated. its starts well cold too. Quote Link to comment Share on other sites More sharing options...
swag Posted July 28, 2006 Author Report Share Posted July 28, 2006 oh man do i feel silly. one of my silencers was messed up. the core had come loose on the frt side and was half blocking the pipe off. i knew it would be somthing simple. Quote Link to comment Share on other sites More sharing options...
dajogejr Posted July 28, 2006 Report Share Posted July 28, 2006 rt side .090" and lt side .080" over fresh bore from trusted shop, A trusted shop let you put two different oversize pistons in your bike? I hope you typed that wrong, I fear you didn't. You are headed for problems, gaurenteeed. I'm sure it'll run ok for a while...but, that's just bad practice. Would you tie one shoe only half way up? Put the tires on the left side of your car at 35PSI and the right side at 30PSI? At least they're new pistons, right? I mean...he didn't use the old .080 over piston but give you a new .090 over, did he? That's just bad news...period. Like I said...I'm sure it'll run for a while, but you're headed for headaches.... Quote Link to comment Share on other sites More sharing options...
spunmonkey Posted July 29, 2006 Report Share Posted July 29, 2006 I have heard of people using two different size pistons before. I was told as long as they are the same weight there should not be a problem. We are not talking a 80 over on one side and stock on the other. I read on trinity's website that most people have a problem with one cyclinder being slightly richer than the other. Good to see you found your problem though. Or one being leaner than the other. However you wanna look at it. Quote Link to comment Share on other sites More sharing options...
dajogejr Posted July 29, 2006 Report Share Posted July 29, 2006 Somewhere on here...or another forum, is a post about Wiseco A, B and C pistons. Now, I can see if this was the case, but it's not. If he already bored out one of them to .090...why not the other too? I don't get it. Quote Link to comment Share on other sites More sharing options...
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