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jetting help please

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Hi everyone im new to thumpertalk and im from the gold coast in australia what a web site, this is awesome, well to start with i own a KX 250f 04 it has a muzzys full ti system on it a zip tie air mix screw pro taper bars 49t talon rear sprok on back and a 13 front over here we have a fuel called shell racing 100 it is a leaded fuel which is 110 octane with a -30 flash point i ride my bike at up to 800ft altitude temps from 18 to 24celsius winter to high 30celsius in summer (not sure what that is in fahrenheit)with humidity always in the 90s just want some ides on jetting for this fuel been running unleaded 98 pump fuel but wanted to change to the leaded as it is easier on the valves thanks for all your time also going to the supercross masters at the brisbane entertainment centre on saturday night for round 3 the rock Mike Larocco is going to be there from the usa cant wait to see him ride just a dame shame he rides a honda sorry honda fans

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1st 4 strokes dont like high octane gas.need to run lower octane.i would try a 182 main, 40 pilot, clip in 3rd position,2 turns out on fuel screw.

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Scuba thanks for the reply but i do have to say id love to know where you guys are getting your info on saying high octane fuel is bad first do you know if it is leaded high octane or unleaded high octane i bet it is unleaded high octane all our magazines over here are saying to run avgas cause its great for your valves it gives them a cushioning affect and prolongs wear which is true cause i have a friend running avgas and he is getting alot longer riding time between shimming the valves and also i think his jetting is wrong thats why im here asking for some advice so please come on everyone else some more advise on jetting

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As far as using race gas, anything over 100 oct. on your stock bike is just blowing $$ out the end of your pipe. if you mod your bike and raise the comp up then that is where the higher oct. comes in to play. The high oct. fuel has a slower more controlled burn than pump gas. to high of oct. can make less power than pump gas on stoke bikes!

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my Son rides RMZ great bike,the bike is stock except a Boyseen water pump(now in Aust) which I recieved yesterday , all i've replaced is the clutch and the rings,only because it blew a head gasket.I run Mobil premium with Motorex valve guard added and have so far have had no problems. He races in central Queensland and practises two to three times a week.i know of another rider using avgas and he to has had no problems what jet settings i'm not sure i'll find out this weekend but i don't think it's worth the hassle.

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Look up JDjetting on this web site, his setups are the best.

His jetting kits are about 60 bucks and well worth it. I tried Pro Circuits jetting specs and I did not like them, some people do, but I bet they havent tried JD.

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