ybr125 (carb) - won't start on a warm engine?!?!

[jamesfoster]

Hi all, sorry to raise conundrum on my first post, but this is driving me mad, so hope anyone can possibly help with an ignition problem on my ybr125 07 plate (carb version)

since around november last year my bike has been reluctant to start with a warm engine, eg i've taken it out for a run, stopped, and couple of minutes later when i'm ready to go again, my bike doesn't want to start.

it will start fine from a cold engine on or off the choke, and once it is running (hot or cold) it runs fine and you wouldn't suspect a thing. i did suspect it might be the coil breaking down but the replacement hasn't seemed to make a lot of difference as it still is playing up....

so far i've replaced/serviced/cleaned the following: cleaned air filter, replaced coil & ht lead, replaced plug cap, new spark, carb cleaned, seal replaced on inlet manifold where it was blowing. the spark colour is fine and the mixture isn't too lean/rich etc

one consideration - before i took the bike on last June, it had been garaged for about a year with an almost empty tank, and i suppose there is a possibility that some gunk might have accumulated in the tank - but like i said, when its running you wouldn't notice anything was ever wrong with it. one last thing i'm yet to do is put some Redex through it when i fill up next.

any ideas? it is driving me a bit mad, and making me really think hard about where i get petrol from.

please help!

cheers

James

[blackhat250]

Hi james. the fuel tank gunk. would make it a non starter all the time, i think its Choke related . when the choke is off , it might not be seated properly, is it a cable operated choke ? or lever? . either way ,take it out and inspect the plunger seat washer.

if its cable , loosen it a few turns too.

Then we"ll talk about compression

[AndrewElvisFan]

I had a similar issue with my SR - it turned out to be the float. You may get more responses if you post an intro here and workshop question in the workshop section!

[DirtyDT]

Posted in the wrong section. Post locked.