Cold Start GPX 250

[mobile]

Ok, not sure if I missed a post simiar when scanning, so here goes, 1994 GPX 250, if I let it sit for say 2 days and then try to start it, she takes quiet a while for her to get going, have tried the Choke just open, two squirts of throttle, and then W.O.T when starting and out of 3 attempts this has worked once, so here's my thinking, fuel bowls are enptying themselves(due to what, not sure), valves need checking, insufficent compression on start up (no running problems though), or last of all another issue, on a side not, my choke seems to want to stall the bike if I turn it up over 3/4. Any suggestions?

Mobile

[mike-s]

Firstly r.e. the choke, who knows, some bikes love the choke, others hate it. I had a el250 (same engine, different chassis) and i had to give it 3/4 -> full choke and couldnt touch the throttle for the first minute or it'd just conk out cold and i'd have to try again. Try 3/4 choke and just a *touch* of throttle (like you take up the slack on the throttle cable and are just applying slight pressure on the throttle, barely even moving it) This worked for my 250.

Regarding the fuel bowls emptying themselves, once the vacuum switch is enabled, fuel just keeps pumping through, regardless of how warm or cold the bike is. So you can get it running eventually i guess. regarding this idea, how does it go if you take it for a blat and then let it idle for 10 minutes? does it conk out or keep going? if it keeps going, definately not a problem with the vacuum switch / floats. Other than that i cant see how it'd be a problem...

Compression? Just do a compression test firstly (also you can get a bit of an idea on how good compression is by placing your hand over the exhaust pipe)

Do the valves need checking? when were they last done? Maybe they are due, these 250's have the gaps close up often, when has the past owner last had the valves redone? at the worst you'll just ensure that the bike is in-spec, at the best you'll fix the problem.

And lastly out of curiosity, how does she go if you leave her for 3-4 hours after she runs (enough to get cold again) and then fire her up once more?

[Glen]

We had EL250's on our training ranges and at times they were buggers to start. We used to go full choke, no throttle and this used to work most of the time, they seemed to take a while to warm up though.

If we had a problem child that wouldn't fire as above we'd do the reverse ie Full throttle No choke and that would work.

Good luck

[mobile]

Firstly r.e. the choke, who knows, some bikes love the choke, others hate it. I had a el250 (same engine, different chassis) and i had to give it 3/4 -> full choke and couldnt touch the throttle for the first minute or it'd just conk out cold and i'd have to try again. Try 3/4 choke and just a *touch* of throttle (like you take up the slack on the throttle cable and are just applying slight pressure on the throttle, barely even moving it) This worked for my 250.

Regarding the fuel bowls emptying themselves, once the vacuum switch is enabled, fuel just keeps pumping through, regardless of how warm or cold the bike is. So you can get it running eventually i guess. regarding this idea, how does it go if you take it for a blat and then let it idle for 10 minutes? does it conk out or keep going? if it keeps going, definately not a problem with the vacuum switch / floats. Other than that i cant see how it'd be a problem...

Compression? Just do a compression test firstly (also you can get a bit of an idea on how good compression is by placing your hand over the exhaust pipe)

Do the valves need checking? when were they last done? Maybe they are due, these 250's have the gaps close up often, when has the past owner last had the valves redone? at the worst you'll just ensure that the bike is in-spec, at the best you'll fix the problem.

And lastly out of curiosity, how does she go if you leave her for 3-4 hours after she runs (enough to get cold again) and then fire her up once more?

Mike, once running, and after a few hours, she is perfect, it really is only if it left for 2 or more days.

[mike-s]

Hmm, in that case i would put about 1/3rd a bottle of wynns carby cleaner into a full tank of fuel, do this two tanks in a row, i'd take a guess and say that something is sticking, or clogging up.

If that doesnt fix it, it might be carby overhaul time.

Last thought in case its something else, it doesn't have trouble cranking the starter motor over does it?

[mobile]

Hmm, in that case i would put about 1/3rd a bottle of wynns carby cleaner into a full tank of fuel, do this two tanks in a row, i'd take a guess and say that something is sticking, or clogging up.

If that doesnt fix it, it might be carby overhaul time.

Last thought in case its something else, it doesn't have trouble cranking the starter motor over does it?

Nah, no problem there, as I have just purchased this in the last month, have given it a birthday, but am going to give it a proper one soon(i.e. mechanic shop), but will do two treatments of carb clean before then. Thanks Again