Ask the Editors: Smokey 250X
Go with your gut on this one – the air cooled Honda TRX250X is a relatively simple design. It is possible, however, to get smoke from such factors is worn valve guides or a blown head gasket but you can generally rule these issues out just by starting the machine up and studying the smoke.
Does it produce smoke all of the time or only when revved? Is the smoke blueish or gray/ white? Does it smell oily? And lastly is it coming only from the muffler or seeping from the engine itself?
If you suspect the head gasket, a simple compression test will let you know for sure but our educated guess would point to worn rings like you suspect.
The good news is a top-end rebuild is quite affordable on this model (use the opportunity to set your valve tolerances (.004), install a fresh piston in with those rings and of course replace those gaskets). Once you’ve freshened these things up, the bulletproof nature of the Honda mill should have you running strong for years to come.
