Rpm sticking when cold

[Tjm1801]

I'm really baffled by this problem,(it's probably an easy fix) but the bike is 2 stroke carburetted 50cc ,when the bike is cold ish it will rev to about 3k and then stick until I let off the throttle or change up a gear to wait for it to warm properly, then it will work no problems. I have recently put new reed valves in but I made sure to remove any air leaks as it was a problem before.

[Tango]

Welcome to TMBF mate. .....pop over to the Newbies section and introduce yourself to the guys when you can. ......

Does the bike have an automatic choke?.........

[mikestrivens]

Hello and welcome

[Mississippi Bullfrog]

Is something in the mechanism gummed up? I've had cable operated carbs do similar things when people used WD40 to lube the cable or mechanism. WD40 is not a lubricant - it is a dispersant (which is what the D stands for) so it drive out lubrication. I use a spray with teflon in it and that seems to sort this kind of thing out.

[Tjm1801]

Welcome to TMBF mate. .....pop over to the Newbies section and introduce yourself to the guys when you can. ......

Does the bike have an automatic choke?.........

 

Cheers and I will do, Noit has a manual choke although we had to strip it before as it was stuck. Should I check it again?

[Tjm1801]

Is something in the mechanism gummed up? I've had cable operated carbs do similar things when people used WD40 to lube the cable or mechanism. WD40 is not a lubricant - it is a dispersant (which is what the D stands for) so it drive out lubrication. I use a spray with teflon in it and that seems to sort this kind of thing out.

 

It had brand new throttle cables because the last one rusted through I didn't lubricate it because of the Teflon coating inside, I don't think it's the throttle as it will allow me to back off the throttle with no problems.