I have a troy bilt 18.5HP Bronco riding lawn mower. This spring, I started it up and it ran good for about 10 minutes. Then it began to smoke pretty bad, I turned the power down, it stopped smoking. I ran it for a about another 10 minutes and it did it again. It then ran well for a lawn mow. It is now doing it every time I start it up. It continues to do it intermitently. Any ideas? Thanks

The problem of smoking at start up is usual. Now when you say it continues to do so, do you mean while running at the same rpm, or when you go from low rpm to full throttle?

Thanks for the reply and follow up. The mower actually does not smoke till about 10 minutes of operation. When it begins to smoke, I stop the blades from turning, turn down the power and it eventually clears up again. It then later returns about 10 minutes later while running.

What color is the smoke, I'm thinking you might be flooding out due to a bad needle valve.

The smoke is white and is very thick.

Clean the carb and the powl paying particular attention to the seat and needle valve.

I took the carburator apart and replaced the fuel solenoid.It is still smoking. I noticed it only smokes intermitently when I am at high RPM's and the blades are engaged.