A forum for owners of Yamaha TTR250 trail and enduro bikes!

bolt250 · Newbie

I think I've ruined my bike... Help!

TTRfan · Super Guru

Hi there and welcome to the forum!

There a few basic requirements for the TTR to start and run which include a supply of petrol/air mixture, a decent spark at the plug and some compression in the cylinder.

It sounds as though your problems are carb related and it is worth checking you have a proper flow of petrol by undoing the drain screw at the bottom of the float bowl and let it run out for a short while (don't smoke during this operation!) which will also clear out any water or debris that may have gathered at the bottom of the bowl.

If that all looks OK then you may have a blocked pilot jet which is quite common in which case you will need to take off the carb and get it properly cleaned out.

I am a bit confused as to why it won't start with the "aerostart" which makes me think maybe the plug is fouled? It may be worth getting a new plug and sticking it in just to rule out any problems on that front.

Lots more info here http://ttr250.activeboard.com/t45670479/help-ttr-250-wont-start/

Good luck and let us know how you get on!

Brian

bolt250 · Newbie

Cheers Brian,

I've taken it al apart ow and stripped the carby, the jets all seemed fine, but the check valve which sits in the float bowl was stuck, have left all the parts soaking overnight in the Yamaha "specially formlated" soaking fluid (which i'm pretty sure is just degreaser and penetrene...) and hoping everything goes back together and works tomorrow... A promising sign is that the engine will run if i just spray aerostart straight down the manifold while i crank it over, hopefully meaning my ignition is all good! I'll let you know how it goes tomorrow...