TRF Forums

well ive gave up and put it into another shop after trying everything today the shop said it could possibly be the hot start lever sticking but it didn't seem too bad.

reading into the problem a bit more sounds like it may need a bigger pilot jet could be running lean at tickover the pilot screw was already out 3 turns

What your doing is guess work you need to take it to someone with a dyno

thats where its just come from i'm afraid and its now ticking over and idling worse than ever its had the main jet dropped loads to 150 as the dyno said it was running rich

Too late I know, and at the risk of sounding like your Dad. I had a WR250 last year. It ran spot on always but thats because I left it standard... even the exhaust. I have always left my bikes standard spec and never had any running probs. If you fiddle you will pay the flat spot or spluttering/bad running game forever in my experience. If you want to go faster I reccomend you sell the 250 and buy 450F like I did, and leave it standard. You cannot beat swept volume !

Sounds like a blocked slow running jet. Clean it and when you think it`s clean, do it again !

which one the slow jet? is that the starter jet/pilot jet or pilot air jet etc??

take it to someone who has a dyno and knows how to use it.. like hm racing

wat pipe are you running?

standard the bike is all standard apart from been rejetted

Not to be funny but why are you even messing about with jetting on a standard WR? what are you trying to acheive because the standard pipes always run best with standard WR jetting weather it be 450 or 250.

If you want a pipe that gives some increased performace and sounds nice then you should of bought a DEP S7 full system as this is the only pipe that works with stock Yamaha Jetting and gives a very good result No popping or banging excellent from the bottom up. Trust me Ive tried and tested it myself.

Ive also tested leo vince and FMF pipes they all need jetting to suit the DEP S7 doesn't as the WR 250 07-09 comes jetted rich as standard

The slow running jet is usally the sunken in small one. I cannot tell you which side to look or EXACTLY what it will look like on a wr250 because although i owned a 250 for nearly two years, I never needed to remove the carb. This is because I left the jets, and everyting else standard.