Hi Everyone,

I have a problem with the start up of my YBR125. The bike will start with the choke reasonably well but after a few minutes, the bike struggles to even slightly rev up (after necessary adjustment to choke). As a result, the bike cuts out.

I must point out the bike runs beautifully once fully warmed up.

The bike has been into Yamaha and they have said there is nothing wrong with it, I think differently.

All my other bikes (owned a few) I've been able to start, leave to warm up for a few minutes, get on and go. This bike is quite the opposite.

Could anyone help with possible solutions?

Thanks and Regards,

Mike

my dt125r does the same mate, fires up after 2-3 kicks from cold with choke, leave to tick over for a min then start tickling the revs and she bogs and cuts out fire it up again let it tickover with finger on choke leaver (as the choke on my dt drops automaticly after few seconds of running) tickle the throttle and then she is fine...

kicks over first kick once warm, i just thought it was normal as tempreture is starting to drop through the night - was frosty this morning so i let her warm up for a good 10mins

ive had a few bikes also on and off road and they have all been different on startup, some dont need choke some need longer time on the choke.

maybe its just your bike needs a little bit more warm up time before trying to rev her

ken

Thanks for the reply Ken.

What I will add is that if I set off too soon, the bike really stutters and can cut out.

I had an old CG125 '51' plate that I never had the problem with, had alot more miles on too. The YBR has only done 1450 miles so it's hardly been excessively used.

It has to be either a fueling issue of some sort or maybe a sparking problem...that's all I can think of.

Mike

Have you checked the spark plug? It is possible that the choke needs to be shut off either earlier or later.

I might just try a new plug in it to se if that makes a difference. Thing is I've just had it serviced at the main dealer and they said there was nothing wrong with it.

Tough one to work out!!!

Mike

See if you can get an iridium plug for it.

All bikes have a certain starting techniques.

http://125ccbikeclub.awardspace.co.uk/servicing.htm#Ethanol in Petrol Warning

If you use supermarket fuel like I do, try something else.

My fuel injected ybr has a similar prob, sometimes it stalls when idling or at low revs.

Also, if I snap the throttle on it'll die, gonna fill up next time with quailty fuel and hope that helps.

BTW, did you change the spark plug?