so im getting around 180 pounds of compression. im breaking it in on 93. but should i move up to 110 racing fuel. ive herd man different things so i dont know which to use. help please? thanks so much,god bless yall.
250r: racing fuel or not?
- Thread starter chumley1/17/96
- Start date
run the lowest octane fuel that doesn't produce detonation, try the 93 and listen for deto/pinging
if any is heard, try a mix of 93 and 110
constant checks of the plug for signs of it also
till you find what works for you
if any is heard, try a mix of 93 and 110
constant checks of the plug for signs of it also
till you find what works for you
I'll provide the technical answer but what Awk suggests is really right. No technical answer can tell you FOR CERTAIN that one engine or another needs higher octane fuel except listening to that particular engine....
The technical answer is, the rule of thumb on an air cooled blaster is that about 165psi is the limit on pump gas. Any more (any way you slice it) and you'll be pushing the fuel too hard for the head and cylinder temperature to not pre-detonate it. Air cooled cylinders and heads are thicker to act as a heat sink which also prevents heat from escaping. The result is that the innermost layer of aluminum is hotter than in a liquid cooled engine.
In a properly designed head that's liquid cooled, it's completely possible that 93 octane will run smooth and quiet even at 180 psi of compression.
thats what i first herd. is its over 165 psi or 170 psi i would have to run it on racing fuel. ill put a video on youtube tomorrow with a start up. cause idk much about this r. i bought it as a project and just got it runing. it seem to run okay. but i think the carb need rebuilt cause it leaks bad out of the overflow.
but when i started it for the 3rd time i i had the chain an sprokets off and started it and it started getting in high rpms like i was holding the throttle all the way down. idk what caused that. maybe carb issues?
carb fuel level, or dirty carb issues
or an airleak, better get it leak down tested
