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first time running 110 octane in 03 cr250

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alright, well i have a 2003 cr250 with v force 3 reeds, kehin carb, jd jet kit, ported, fresh wiseco top end.. and lots more.. and i always ran 92 octane, but the bike made some weird noises, it alway make lots of clanking noises, and other random noises coming from the engine.. today i tried out some 110 octane and WOW what a difference, for starters all the noises are gone, and there is so much more power, and overall the power feels cleaner... just wanted to know what octane you guys run and if you have had these noises with lower octane fuel as well..

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supposedly those bikes detonate pretty easily stock. the higher octane gas essentially increased your power and smoothness because you actually had proper combustion versus detonation.

you can probably save yourself a good chunk of change by mixing 50/50 with that 92. using 110 you can even mix 70/30 and that should still be more than enough to stop the issues you were having. this will allow you to save some money and still get the same benefits.

i have not had any issues running 91 octane gas in my 2000 cr250, but the 92-01 engines arent known for detonating in stock form on pump fuel like the 02-07 engines. however, i started using a 50/50 mix of 100 and 91 octane anyways.

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My Dad and I used to buy a 55gal drum of high octane race gas and run 50/50 with gas pump. That was good enough to keep it running pretty good.The full race gas is great but is expensive. ..also .. I've had a bad habit of trying a whole bunch of different octane boosters and different oils. Certain batches end up better than others but just adding the boosters does help. I've been using performance plus and that seems to help a bit also .

http://www.manhattanoil.com/go-karts.php

I never run just straight pump gas unless I run the power plus...Not as good as race gas but improved enough. I also have run mixed klotz race gas 50/50. That works alright too but I'm not into buying individual gallon containers at a time. I went to the additives and power plus type oils when the regular gas prices went up to $5 per gallon a couple of years ago. There's one high octane booster that supposed to be for offroad only..It has MMT or something and comes in a round taller can with flames pictured all over it. I got it at Checker auto parts and that worked good enough and of course is cheaper and doesn't take up so much room in the garage. Race gas is the best but some other octane boosters will get rid of some of those noises too and probably at a cheaper price. I've heard good reports about lucas booster but not tried it.

This liquid horsepower works pretty good too...from the power plus guys.

http://www.manhattanoil.com/octane-boosters.php

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is it possibile that my ignition timing may be slightly off, causing the detonation which occured so often with the pump gas? or is it normal or there to be a lot of detonation with the 03?

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My stock 03 has been increasingly intolerant of the garbage ethanol pump fuels in my area to the point of having detonation so bad it sounded like a handful of steel marbles rattling in the jug. I chased jetting for a while, and then finally switched to vp c12.( after having tried mr2 and others in the past) Problem solved with the bonus of more stable jetting, and more track time vs jet swapping in the pit all day. Of course many blame this on inconsistent squish from Honda. The gas was the fix for me, as I like a stable reference for jetting. if I ran several bikes, I'd try find a way to make pump fuel work.

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hmm so maybe the pump gas gunks up engine after a while.. cause i also noticed the noise got worse... seemed as though it started as a random knock but soon became what you are talking about.. just like steel marbles rattling.. but i drained the fuel and gave the 110 octane fuel a try and it all cleared up

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I'm running an optional needle jet in mine, I believe its this one. Got the idea from this Dirt Rider test. They list it as GBEH2-72 which I couldn't find anywhere. Then I read on the DR forum its an optional jet from the '01 CR250, closest I found is a 6BEH2-72. 95% sure thats the one I'm running.

Anyways, the bike runs a bit crisper and once I got the needle dialled it never detonates on pump gas.

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I run 50/50 92or 93 with 110 leaded VP racing fuel (purple) she runs great!

2006 cr250r

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I've heard of stacking 2 head gaskets to bring the compression down a touch to relieve detonation. Never done it myself.

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