hercalmighty Posted December 12, 2014 Report Share Posted December 12, 2014 For shits and giggles I would try 93 octane pump gas and see of what it does. You might be way over octane with the 110. Maybe at most 100 octane Quote Link to comment Share on other sites More sharing options...
hercalmighty Posted December 12, 2014 Report Share Posted December 12, 2014 Also, the .059 base gasket seems really high. It might be throwing your port timing off just a bit. What kind of deck height do you have with the .059 base gasket Quote Link to comment Share on other sites More sharing options...
camatv Posted December 12, 2014 Report Share Posted December 12, 2014 that is a super thick base gasket. that would mean you dome step is nearly nonexistant. your jetting is off. its that simple OR you have a synch problem, fuel supply problem, or ignition issue. you need to concentrate more on the off idle performance get the bike to roll on very nicely and run a really rich main till it does that. then check stuff like spark gap, plug resistance, ignition pickup gap, plug cap resistance and you will need massive fuel delivery to enable you to run much high rpm for very long. including most likely another power jet added. you will have to watch your egt's if you make very long runs as they will continue to rise rapidly. 52-58 squish clearance is fine DO NOT tighten it up infact going to about 60tho may be even better for really long runs. i would also highly suggest putting the PV's back in it. Quote Link to comment Share on other sites More sharing options...
Deadbeat Posted December 12, 2014 Report Share Posted December 12, 2014 what about his power valves pulsing at cruise, how should he address that, or is his current set up causing it Quote Link to comment Share on other sites More sharing options...
lt1bird Posted December 13, 2014 Author Report Share Posted December 13, 2014 The bike is running very clean. Down low.....even right tru 1/2 throttle and higher...maybe just a tiny bit rich at 1/8throttle..... Very happy everyplace else... The power vales use to pulsate a lot at 1/8 throttle just putting along....ran very crapy...pulled them off and so much nicer....quite and smoother...Ive actually Gita backup plan...I've got 2 fuel solenoids....going to put one each in the power jet lines....open the solenoids at 6k rpms via my ignitech...should work good... Quote Link to comment Share on other sites More sharing options...
trickedcarbine Posted December 13, 2014 Report Share Posted December 13, 2014 Ultimately the valves are the way to get it to have bottom-mid. Otherwise that thing has to be in the rev to come alive and it can be a goofy feeling getting it there. Any timing in it? To be honest, the 180 main sounds a bit rich to me as well. Quote Link to comment Share on other sites More sharing options...
trickedcarbine Posted December 13, 2014 Report Share Posted December 13, 2014 what about his power valves pulsing at cruise, how should he address that, or is his current set up causing itThis is caused when the bike is rich condition and or needing different jets in the PV. The cheetah uses Keihin hex jets for adjustment. The motor draws excessive fuel and begins tryig to light it with null result. In turn the bike begins to make heat and then is quenched, over and over at part throttle. This creates I constantly changing exhaust pressure which pulsates the PV. Now add that the valve it self is floating and the two issues become a compounding problem when tuning. I've only recently got to fiddle with a cheetah, putting a larger jet in the valve could aid in that, but ultimately it would be coming on later. This could allow you to eliminate a goofy variable while you jet. Once dialed in go back to the smaller jet in the PV. There is nothing wrong with the porting from CP Ind. cleaned up, and they have a lot of potential. As long as someone doesn't use the trinity domes or let them port the thing, it should be good. Now that Harry is back to just the small shop, anybody know how the cheetah parts supply is flowing? Quote Link to comment Share on other sites More sharing options...
lt1bird Posted December 14, 2014 Author Report Share Posted December 14, 2014 I think you nailed the power valve issue...that is exactly what it was doing... you could hear the valves slapping around...one broke at one point.. im just not a fan of them..... 180 main jet...yes, I feel its to large as well. I had a 162 in there...ran great...a bit lean... went to 180.. trying to get it to 4 stroke...and it still pulled hard but the egt was a cooler but not in the 580 range yet. im like...I was looking at the jetting last night....I really wonder if my DGH needle is just too rich at 3/4 throttle... I might try leaner taper needles...drop the main jets to 150 and use the power jets...see if that helps.... Quote Link to comment Share on other sites More sharing options...
sleeper06 Posted December 15, 2014 Report Share Posted December 15, 2014 It sounds like you want the power valves back in , and I have never ridden a two stroke you can lug in 4th then wack it and something good come from it Quote Link to comment Share on other sites More sharing options...
trickedcarbine Posted December 15, 2014 Report Share Posted December 15, 2014 ^ yeah.... Quote Link to comment Share on other sites More sharing options...
lt1bird Posted December 17, 2014 Author Report Share Posted December 17, 2014 I think I would rather down shift a few gears to get some power before I would put the power valves back in... im sure once ive tuned it a bit more it will get better..... the aprilia rs250... 62Hp to the wheel on my stock bike... high strung....power valves...you could lug it all day.... that's the difference between a drag setup(banshee cheetah cyl's) and a road race/street setup.... it is what it is.... ill keep you guys posted.,...thanks a bunch for the advice Quote Link to comment Share on other sites More sharing options...
lt1bird Posted December 17, 2014 Author Report Share Posted December 17, 2014 This is the 485cc cheetah powered bike.....280LB wet..... aprilia rs250 based... Quote Link to comment Share on other sites More sharing options...
apeik Posted December 17, 2014 Report Share Posted December 17, 2014 That's effin clean looking. Quote Link to comment Share on other sites More sharing options...
sleeper06 Posted December 17, 2014 Report Share Posted December 17, 2014 That's real nice bro good shit Quote Link to comment Share on other sites More sharing options...
lt1bird Posted December 18, 2014 Author Report Share Posted December 18, 2014 thanks guys....I love it too.... built it a few years ago...now finally have time to tune... Quote Link to comment Share on other sites More sharing options...
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