the bike is a 1980 xl250s. single cylinder 4 stroke. the reason i think i might have a blown head gasket is because the oil doesnt sell normal. it almost has a slight smell of gas. it doesnt look milky and there is no cloud of white smoke out of the back. the engine sounds normal and it idles and revs with no issues.

am i just imagining things? or is there another way to check if it is really blown?

 

Id say your just imagining things. Oil will smell a little gas like. After all, gas is made from oil. Plus, the only thing seperating the oil and the combustion chamber is the piston rings. Any amount of blow by will go directly to the oil. This is especially noticable on older design engines that had more blow by than modern day engines.

If the smell is really strong, you may have an issue with the petcock not shutting off. If it is, gas can overflow from the carbs into the cylinders, then if it sits there long enough, it can go past the rings and into the oil.

Having said this, in your oil is not increasing in level, does not look funny, I wouldn't worry about it. More times than not, a blown headgasket will result in coolant in the oil, or oil in the coollant.

It sounds perfectly normal for used oil to have a little gas odor. I think your bike is probably fine.

 

thanks. yeah the bike is air cooled so i think your right. plus i can see the gasket where the top end and bottom end meet and it looks fine. im just needed some reassuring lol.