Thanks yoda, that certainly sounds possible but what could the cause of the carbs overheating be? and what could i look at to try and solve the problem?
The bike is totaly standard set up and no aftermarket cans and no re-jetting to my knowlage although i cant speak for it's history. Ive owned it for a year and to be honest it has done this after the first couple of months of having it. There was a slight concern over the coolant pump when i was buying it, it seemed to be rattling a bit, but problems never materialised with engine overheating. the rattling was put down to the bike being sat for a while and stopped soon after i used it.
Im quite sure The choke mechanism is closing fully , and all the brass pins move in and out the front of the carbs fine, but can the mech inside the carb still be broke or stuck open if those pins move OK on the outside?
I dont think any fuel drips out the overflow pipe, but will check on saturday. And i replaced the air filter last week with standard Yamaha part, this sadly does not solve my problem although the engine breathes noticeably better.
I did notice however when the air filter was out, inside the airbox there was a splatter of petrol behind no 2 carb and a small puddle. also when changing the spark plugs no 2 was slightly wet on the thread. the rest were dry - does this ring any alarm bells ???
Cheers,
Mike.