Stonytony Posted August 5, 2013 Report Share Posted August 5, 2013 Hi. My question is weather or not if I should up the fuels octane ive been told run 113 oxygenated. I run 110 now. Machine specs are Dune/drag port 65.5mm bore stock stroke Vito's fat bastard in-frame pipes 4+ timing Coolhead 19cc domes 135psi 30 pilot 320 main vitos needles mid clip stock carbs Vforce2 reeds and reed spacers Quote Link to comment Share on other sites More sharing options...
sheerider11 Posted August 5, 2013 Report Share Posted August 5, 2013 And your giving out advise?? Your an idiot. Who the fuck told you to run anything other then pump? Quote Link to comment Share on other sites More sharing options...
Stonytony Posted August 5, 2013 Author Report Share Posted August 5, 2013 Jugs are good. I checked end gap on rebuild last week and its .012 with feeler gage it's tight but the .013 won't fit. If it gets beyond .015 that's out of spec according to the piston manufacture .010-.015 is tolerance Quote Link to comment Share on other sites More sharing options...
Stonytony Posted August 5, 2013 Author Report Share Posted August 5, 2013 First these machines as designed were made to run premium 93 octane at stock 110 psi compression. When compression is raised more heat is generated so a colder burning fuel must be used. 19cc domes are a high octane fuel dome due to its shape and paired along side increased compression 110 octane or higher is a must. Sheerider11 you must burn up alot of pistons. Quote Link to comment Share on other sites More sharing options...
possum Posted August 5, 2013 Report Share Posted August 5, 2013 oh no Quote Link to comment Share on other sites More sharing options...
sheerider11 Posted August 5, 2013 Report Share Posted August 5, 2013 Burn em up all the time. Could not figure out the detonation issues. 136psi and the just explode. I'll start running 110. Quote Link to comment Share on other sites More sharing options...
Jereme6655 Posted August 6, 2013 Report Share Posted August 6, 2013 FIRST.....these bikes are RECOMMENDED to be run on A premium fuel (by premium they mean a quality fuel) with a stock compression of approximately 125psi. Second....When you up compression you DO raise some combustion chamber temperatures......but who the fuck said that race fuel burns "cooler".........its not because you need a "cooler burning fuel"..........higher octane fuel is MORE STABLE.....so it is less prone to spontaneous combustion due to excess heat which can be caused by high pressure or high heat. Third......19cc domes are USUALLY high compression, high octane domes...........BUT there is no specific "this is a race fuel dome only".........there are too many variables based on motors, weather and elevations. NOW......you haven't mentioned whether you have some EXTREME porting or whether you live way up at the top of a mountain........but 19cc domes and 135psi usually don't go together. I am running 20cc domes and kicking over 152psi and I am still on 93 fuel. And that is with porting. With 19's in there I was well into the 170's. Now........go figure out why your motor is making low compression. weather it be altitude or you forgetting to hold the damn throttle open during a compression test.......there's something wrong with your numbers. Quote Link to comment Share on other sites More sharing options...
possum Posted August 6, 2013 Report Share Posted August 6, 2013 I had 165 lbs with 18 cc domes stock cylinder 198 130 durations. Quote Link to comment Share on other sites More sharing options...
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