My bike had been running fine, then I noticed the odd surge now and again, next time I came to start it it was difficult but eventually fired up. A mile down the road it died as if it had run out of fuel. I suspected dirt in the fuel possibly blocking a jet. Drained the float bowl and managed after a little while to get it started and returned home.
Now I've removed the carb twice, blown out everything that has a hole replaced the carb with an in-line filter and now it starts without choke doesn't respond to where I set the slide it is running a little fast and when I blip the throttle it is not crisp as it was and doesn't settle down straight away.
The slide seems to work as it should, so I'm befuddled as to what's wrong.
Sounds like an air leak.
If your head is a twin carb type and has a balance pipe, give it a tug and make sure it isn't loose.
Other than that, start the engine and spray around the carb mounting with WD40, WD40 won't ignite and the engine will bog down if there is a leak. You can spray easy start and this will increase revs if there is a leak, but it could also risk a fire. Most people also have WD40 In their garage also.
After that, check ignition timing and ensure the engine isn't running lean.
I think the problem is head gasket.
Could be but head gaskets don't usually cause crank case compression problems. Unless the oil is leaking down onto that spot and giving you the impression you have a base gasket leak?