Does this make sense? (compression)

[Joshwuh]

I was having some fun on some dirt roads when I had a little too much fun and the bike slid out from under me ('77 XS400). I was going maybe 10mph and I caught the bike for the most part as it was slipping but it still pretty much got laid down albeit gently. When I stood it back up I noticed the engine sounded different and also that I had slightly less power. I could hear the difference in the left side so I felt the exhaust and it was coming out noticeably weaker than the right.

Does anyone have any idea what could have happened? I'm assuming that it was a pre-existing problem and the 'lay down' was the straw that broke the camel's back. But what kind of things affect compression and what are solutions?

I'm going to try and find someone with a compression test kit tomorrow so I can see how big the difference is. Based on my highly accurate 'Hand at the exhaust pipes' test it seems substantial.

 

[drewpy]

maybe check wiring connections first, then give it some gas, maybe the carb float bowl dislodged some muck towards the main jet!

 

[Travis]

Yeah I doubt it's anything with your compression.. probably a fuel issue. Stuck float maybe from the extreme angle. Try tapping on the float bowls with the back of a screwdriver.

 

[drewpy]

Yeah I doubt it's anything with your compression.. probably a fuel issue. Stuck float maybe from the extreme angle. Try tapping on the float bowls with the back of a screwdriver.

and if you get a tap back, somethings trapped in there!

 

[Travis]

If that happens you got bigger problems than your bike not running right!

 

[Joshwuh]

Haha thanks guys I'll try it out when I go home on break. I wish I would have thought of that earlier

 

[Daddio]

One other possibility is to slug the motor, with oil on the top end. It usually fixes itself, if not you fix it the same way as if you get water in the engine, take the plugs out and flip it upside down.

 

[TiZiK]

and if you get a tap back, somethings trapped in there!

Ha haaaa. I actually lol on the train when I read that!

 

[bcware]

My '78 has been laid down a few times. Each time it wouldn't run for a few hours. For me I believe the engine simply became flooded with gas. After the excess evaporated it ran fine.

Did you give up right away and put it away or did you try running it again after a few hours?