VERY High Idle Speed

My Townmate has not run much at all since 2006 now I am getting it ready for the MOT. Horn works now but there is a much more serious problem.

The bike at the moment does not tick over at a sane speed but seems to be revving away like a mad thing. Nobody in their right mind would want to ride it like this.

Where are the screws in the carb on the Townmate? I tried what I thought was the enrichment and another covered up by a rubber grommet. Made no difference. This cannot be much and all I need to fix it to ride down to the test centre.

Please help me tame my T-80!

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Here is diagram of carb showing Idle & mixture screws. Also make sure that throttle cable is not sticking & has free play

get it warm before you tinker with the carb also check the air filter is clean,you may have to change the plug and petrol

My mistake was to fit a sports-style, high-flow air filter to the bike which threw everything out. When I took that off and put the stock airbox back on, I could tame it down to a sensible idle speed. Some people must have tried high flow air filters in the past and I have had one on my Yamaha QT50. Wonder how they work on some machines but not others?

fender wrote:My mistake was to fit a sports-style, high-flow air filter to the bike which threw everything out. When I took that off and put the stock airbox back on, I could tame it down to a sensible idle speed. Some people must have tried high flow air filters in the past and I have had one on my Yamaha QT50. Wonder how they work on some machines but not others?

Seems a bit odd that an air fiter would make that difference especially at idle speeds when airflow is low. Are you sure it was not caused by the throttle cable being snagged up? Another cause of high idle speed that cannot be slowed with the throttle stop screw, is if there is an air leak between carb & cylinder head, or if the small vaccum pipe between inlet manifold & petrol tap is perished/split. A split diaphram in petrol tap would also cause this, although also causing fuel starvation as well. Diaphram cannot be replaced, you need a new tap or use it manually in the PRIME position & blank off the vaccum pipe connection at manifold.

In all honesty, the high flow air filter did not really fit so it may have acted as if there was an air leak.