[mike_k5]

Hi all,

My Friend just bought a crf250 2008 and he's having problems starting it.

I said i would take a look bacause i have the same bike,
I know they can be a pig to start as mine used to be so i began with looking at the valve clearances...

so...the valves were a little out but nothing drastic, and the shims were nice and fat so it looks like they havent been shimmed many times in the past, so i got them back into spec and while the cam was off I also carried out the decompressor mod, because i did this on my own bike a while ago and its worked wonders for me!

Now his bike starts up a bit easier and once its ticking over it runs and sounds perfect, but once you kill the engine it will only ever start when the hot start lever is pulled in, (it needs the hot start even before the engine is fully up to temperature)

my own crf hardly ever needs the hot start (only when its red hot mid race!)

My question is why does my friends bike need the hot start all the time? i would guess is its something to do with the jetting being too rich? or maybe a needle clip needs changing? but i dont know where to start, i dont even know which jet is in play during the starting procedure so id apreciate it if someone with a bit of know-how could point me in the right direction?

many thanks in advance, mike

[mike_k5]

no replies!???
the bike does not start at all if it gets stalled mid race and the engine is red hot...
hot start is needed to get it started anyway whether its hot or cold so im guessing ive got a jet problem somewhere but dont know where to start? leak? main? clip?

any ideas?

[crfsonly]

sounds like your air/fuel mixture is too lean. for example, the hot start works by introducing additional air into the fuel mixture. a hot bike starts better with a lean mixture. if you have recently worked on the carb then check your work and make sure air boots are secure and on correctly. check the hot start cable and connection is good. check your jetting against the jetting databases here as a comparison.

ken

[124]

I'm thinking the opposite Ken. Thinking your running rich. Check jet sizing, float level, and settings against stock. Try running the fuel screw in until you see some type of change.

Just a thought but does the throttle have some slack in it? Check cable routing and be sure the carb slide for proper operation.

[crfsonly]

124...with a more careful reading i see that he's saying only starts with "hot start". i read it as it only starts hot! which is why my first thought was how does it get hot if it only starts hot. that was too early to be posting.

i agree...too rich. good save!

[mike_k5]

Too rich, ok cheers guys i will look at my jetting against spec and get back...