tonyown Posted August 25, 2006 Report Share Posted August 25, 2006 Is it a good idea to advance timing +4 with my stupid 91 octane fuel? a friend told me that I'd have detonation Quote Link to comment Share on other sites More sharing options...
dajogejr Posted August 25, 2006 Report Share Posted August 25, 2006 What's your compression currently at again? Sorry...tonz of threads today. One way to find out...try it...and listen carefully to your motor. If it sounds like someone put steel ball bearings in your motor...back it off. You need to make sure you're jetted correctly, first.... Quote Link to comment Share on other sites More sharing options...
tonyown Posted August 25, 2006 Author Report Share Posted August 25, 2006 Ok and there's no way to use octane booster? a lot of people say that it's shit but I'd like someone tell me why... I like to understand things my friend put octane booster in his 450r he offered me to take some but I didn't cuz everyone told me that its shit Quote Link to comment Share on other sites More sharing options...
dajogejr Posted August 25, 2006 Report Share Posted August 25, 2006 It's shit.... It's not as big of a deal in a 4 stroke because premix isn't involved. First you have to figure out how much octane you need. Then...you have to subtract the amount of gas from the booster you're going to add to get a consisten premix ratio... And...it doesn't really raise the octane a whole helluva lot. I think it's easier and safer to use a 50/50 mix of race and pump gas than to use booster... Quote Link to comment Share on other sites More sharing options...
tonyown Posted August 25, 2006 Author Report Share Posted August 25, 2006 Ok there's a fuel at my yamaha dealer its C4 it think... is it the race fuel u talking about? if I run this mix 50/50 with the c4 can I buy 20cc domes for my futur noss head or 19? I could advance my timing.... and would the wiseco pro lites be enough to take the compression of 19-20 cc with stock crank? thank you Quote Link to comment Share on other sites More sharing options...
Ducman Posted August 25, 2006 Report Share Posted August 25, 2006 If your running on the stock head that hasn't been "shaved" (milled .030) then +4 is no problem on 91 octane. Octane booster does boost octane, the octane of the liquid itself is around 116, the problem is that even if you add a whole bottle to say 2 gallons your still only going to get 92 octane at best because you are diluting it into so much fuel. It is much cheaper to buy race fuel with a higher octane and you get a lot more. PS, you dont always hear detontation, dont ask me how I know. :baseball_wibble: Quote Link to comment Share on other sites More sharing options...
tonyown Posted August 25, 2006 Author Report Share Posted August 25, 2006 ok it answer one question thank you! but when I'll buy my noss cool head could I run like 19 cc domes with the 50/50 mix and my stock crank? or am I better to run a 21cc with the stock not welded crank... Quote Link to comment Share on other sites More sharing options...
dajogejr Posted August 25, 2006 Report Share Posted August 25, 2006 It's a good idea to get the crank welded regardless....even if you left the motor stock. Howerver, if you don't want to get into that right now...personally, get the 21cc domes. And...you probably would have to run straight race gas with 19cc domes, as well. Ducman...that's a good point. You have to keep an ear on your motor, AND an eye on your plugs!! Quote Link to comment Share on other sites More sharing options...
2003LimitedBanshee Posted August 27, 2006 Report Share Posted August 27, 2006 I'm running a NOSS Head with 20cc domes and +4 timing on my stock crank. Until I tear it down this winter and port it. But, it is definitely on the upper end. At sea level it pushes out just over 190 psi in each cylinder. Straight Trick 116 only. Quote Link to comment Share on other sites More sharing options...
greencoloredride Posted September 3, 2006 Report Share Posted September 3, 2006 I'm running a NOSS Head with 20cc domes and +4 timing on my stock crank. Until I tear it down this winter and port it. But, it is definitely on the upper end. At sea level it pushes out just over 190 psi in each cylinder. Straight Trick 116 only. Holy crap. Correct me if Im wrong but isnt 190psi pretty high for only 20cc domes? All my experience is with car engines so I might be wrong when it comes to 2 strokes but thats alot of compression. Quote Link to comment Share on other sites More sharing options...
MDS2106 Posted September 3, 2006 Report Share Posted September 3, 2006 (edited) I'm running a NOSS Head with 20cc domes and +4 timing on my stock crank. Until I tear it down this winter and port it. But, it is definitely on the upper end. At sea level it pushes out just over 190 psi in each cylinder. Straight Trick 116 only. 190psi with 20cc domes Edited September 3, 2006 by MDS2106 Quote Link to comment Share on other sites More sharing options...
tonyown Posted September 3, 2006 Author Report Share Posted September 3, 2006 I ordered noss cool head with 21 cc domes and a ricky stator timing plate I,ll advance timing +4 and run 50/50 pump fuel/race fuel.... Quote Link to comment Share on other sites More sharing options...
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