Thanks for that Grumpy, I had the engine fully rebuilt by a lawnmower shop a few years ago. Can't quite remember now but I think it may have been running a bit faster at idle ever since I had the engine rebuilt. I have cleaned and rebuilt the carby a few times over the years and it's still pretty much got all the original factory rubbers and springs in it from factory. When I got the engine back from the shop I bought new rubber seals for the intake parts of the carby to make sure that it seals properly.
How would I check to see if these crankcase seals are leaking?
I thought that maybe the fuel float and main jet may have been the problem with the fast idle, but after replacing all those bits with new parts it hasn't changed the idle speed at all. So it's definately something else that's causing the fast idle.
The air snorkle is in really good condition with no cracks or leaks, so I don't think it's got a leak anywhere from the air filter all the way into the carby, it might be the crankcase seals as you mentioned, or maybe something inside the carby where this governer and the idle adjustment parts are located.
Thanks again for all the help mate!
