2strokeshees Posted September 20, 2011 Report Share Posted September 20, 2011 I bought this quad running on 110 race fuel. What is needed to go back to pump gas, I have had a few guys tell me they run half an half but I didnt know about that. Can anyone share a little information on my question? Has Vitos 4mm crank, trinity stage 5 head with domes (unsure of what size) never dove into it. .060 big bore, also this guy ran Bel Ray 80w in the tranny. I have never heard of this, I have always ran a 10-40 Repsol in all my 2-strokes, what do you guys say best for a built motor? Thanks in advance. Quote Link to comment Share on other sites More sharing options...
Rotax Raptor Posted September 20, 2011 Report Share Posted September 20, 2011 All you will need to do is buy some domes for your head that are cut for regular gas. Call Andy at m&m (a site sponsor) and explain what you're wanting to do and he van hook you up. Quote Link to comment Share on other sites More sharing options...
Strm Trpr Posted September 20, 2011 Report Share Posted September 20, 2011 Welcome to the site! Warm the bike up and do a compression test. People say 93 octane pump gas is safe up to 160psi kicking compression and no more than +4* advanced timing. Look under the flywheel for an adjustable timing plate and see where the timing advance is. People run up to +7* timing on race fuel. Quote Link to comment Share on other sites More sharing options...
mopar1rules Posted September 20, 2011 Report Share Posted September 20, 2011 Don't follow the guys advice above me and rely on your compression testers reading to dictate what octane fuel to run. Cranking PSI has nothing to do w/what octane fuel to run!!! My buddies stock Solo 681 chainsaw makes 180 cranking psi, and is happy as a clam w/91 pump gas, but my banshee that's 140 cranking PSI would be real crabby w/pump gas. It has 14.8:1 UCCR. You need to know compression RATIO of the motor, to know exactly what fuel to run. I still don't get why this info doesn't get stickied?? Quote Link to comment Share on other sites More sharing options...
mopar1rules Posted September 20, 2011 Report Share Posted September 20, 2011 If you follow compression gauge to dictate octane of fuel to run, you won't only be needing domes from M&M, but you'll need pistons as well. Quote Link to comment Share on other sites More sharing options...
Strm Trpr Posted September 20, 2011 Report Share Posted September 20, 2011 If you follow compression gauge to dictate octane of fuel to run, you won't only be needing domes from M&M, but you'll need pistons as well. OK man... we got it! Quote Link to comment Share on other sites More sharing options...
2strokeshees Posted September 21, 2011 Author Report Share Posted September 21, 2011 haha easy now, I appreciate the help. I havnt done compression test yet, I have just stuck with the race fuel, just wanted to know what I needed to switch to 91 pump. The guy I bought it from said there is 18cc domes in there now, When it comes down to it, I was told to go to a 21 or 22cc dome? Thought I get your guys opinion first tho. I will do a compression test here in a minute to see what each cylinder is at. Quote Link to comment Share on other sites More sharing options...
BigRed350x Posted September 21, 2011 Report Share Posted September 21, 2011 If you follow compression gauge to dictate octane of fuel to run, you won't only be needing domes from M&M, but you'll need pistons as well. Ya! What he said! Rabble Rabble Rabble! Rabble! Quote Link to comment Share on other sites More sharing options...
crash&burn Posted September 21, 2011 Report Share Posted September 21, 2011 When i bought my first banshee it ran on 110 and the guy who i bought it from said just change the domes and it will lower your compresion and you can run pump gas i did as was told not knowing anybetter and blew it up after a half hour of riding and then finding the HQ to find out what the real problem was compresion ratio and some other stuff too. Lucky for you, you found the HQ before you blew your banshee up like me. Quote Link to comment Share on other sites More sharing options...
2strokeshees Posted September 21, 2011 Author Report Share Posted September 21, 2011 After doing a compression test on each cylinder both of them are hitting a dead on 150psi. I was actually shocked to see both were the same. Guess thats a good thing though. So with that in mind. What now? Quote Link to comment Share on other sites More sharing options...
mikechief Posted September 21, 2011 Report Share Posted September 21, 2011 (edited) After doing a compression test on each cylinder both of them are hitting a dead on 150psi. I was actually shocked to see both were the same. Guess thats a good thing though. So with that in mind. What now? well 150 is safe for pump gas... but WAIT! you say you have 18cc domes hmmm Rabble! Rabble! Rabble! Edited September 21, 2011 by mikechief Quote Link to comment Share on other sites More sharing options...
2strokeshees Posted September 21, 2011 Author Report Share Posted September 21, 2011 should it be more, if I pull them out is there anyway of seeing what size they are? Quote Link to comment Share on other sites More sharing options...
mopar1rules Posted September 21, 2011 Report Share Posted September 21, 2011 Don't be worried about having something wrong w/your motor. The psi specs on that chart on noss machines website, is the theoretical readings....just like my tsr software would say I should have something like 182psi on my comp gage w/my 14.8:1 comp ratio, but I don't. Gauges all read a little different and rings don't seal 100% and not to mention, the height of your exhaust port is what reall influences the psi reading on the gauge. If you have 18cc domes, I would suggest you stay on 110. If they are prodesign domes, 110 will be safe, but pump gas won't work for sure. Quote Link to comment Share on other sites More sharing options...
2strokeshees Posted September 21, 2011 Author Report Share Posted September 21, 2011 (edited) So if I wanted to switch over to pump gas I would have to get different domes and maybe re-time? Edited September 21, 2011 by 2strokeshees Quote Link to comment Share on other sites More sharing options...
mopar1rules Posted September 22, 2011 Report Share Posted September 22, 2011 Correct. You would need like 21cc-22cc domes and I would suggest nothing over +4 timing for sure and would stick closer to +2 instead. Quote Link to comment Share on other sites More sharing options...
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