top end engine knock

[gspower]

looks like i will be fully rebuilding this bike after all ....

79 gs425e ... upgraded the r/r unit only to find that the stator is shot. stator in the mail. rebuilt the carbs. ran my tank almost to empty and think i might've sucked some **** back into them and i am having a problem bogging down now. feels like i am running on one cylinder. i will have to fix that.

Additionally, I am now hearing a knock -- definitely coming from the top end, possibly around the cylinder head, left side, generally at lower rpm's though it may be persisting up into the higher ranges too and I'm just too deaf to hear it. I am thankful it isn't coming from the crankcase, but what gives?

I have not adjusted the valves yet (waiting for the end of season) and already noticed my head gasket seeping EXTREMELY slowly onto the outside of the engine. Don't know if this is related but I'm including as much information as I can. I am running without the battery right now until I can get the stator fixed.

Gah. Thoughts?

 

[Sentinel]

The first thing I'd do is pull the valve cover and see how it all looks in there, including checking the clearances. That right there may tell you something, at least enough to konw what to look at next.

 

[gspower]

The first thing I'd do is pull the valve cover and see how it all looks in there, including checking the clearances. That right there may tell you something, at least enough to konw what to look at next.

Mmm. I guess I'll have to at some point. I've also read that carb issues can cause the same symptoms and I'm sure I've got a clogged jet, so ill clean em out and sync em up before I pull it apart. Its time for some maintenance though.

 

[Guest]

Mmm. I guess I'll have to at some point. I've also read that carb issues can cause the same symptoms and I'm sure I've got a clogged jet, so ill clean em out and sync em up before I pull it apart. Its time for some maintenance though.

True statement
Probably need a good sync.

 

[Sentinel]

Mmm. I guess I'll have to at some point. I've also read that carb issues can cause the same symptoms and I'm sure I've got a clogged jet, so ill clean em out and sync em up before I pull it apart. Its time for some maintenance though.

Man, with a knock like that I would not even start that engine until I at least pulled the cover off and checked the valves all I could from there.

 

[gspower]

Man, with a knock like that I would not even start that engine until I at least pulled the cover off and checked the valves all I could from there.

The motorcycle is only firing on one cylinder. My right pipe is cold. I took the carbs off today and cleaned them out. The pilot jets were a little gunked but nothing terrible. When I put it back together nothing has changed. I switched spark plugs and still, nothing. No firing on the right cylinder. At certain RPM's it would seem that the right fires, around the 5-6k range, but it is sporadic at best.

Assuming the carbs and plugs are good, where should I look next? Getting over my head...

 

[Guest]

I'd be checking your points and condensors for spark...

As for the knock, if it's only at idle it could be cam walk where the move slightly left/right, and goes away once you rev it.

If that's what it is, it is of no consequence at all.

 

[gspower]

I'd be checking your points and condensors for spark...

As for the knock, if it's only at idle it could be cam walk where the move slightly left/right, and goes away once you rev it.

If that's what it is, it is of no consequence at all.

I found a loose wire on my ignition coil. Started right up. I still have some concerns but it seems to be running full power again. No knocking. Will definitely keep an eye on it.

 

[Guest]

Nice one, glad to hear it!

 

[Sentinel]

That's great, I hope you have no more issues with it!

 

[tkent02]

Its time for some maintenance though.

It still is.