rough running

[Scudder]

Now that the 78 runs, I've got to work at getting the roughness out. The bike runs very rough and can't hold an idle. It will run, but only when the choke is nearly all the way open, and then of course is blowing rich exhaust. I need to changes some shims because the gaps are not appropriate. I don't have the tool yet, so I'm left too contemplate what else could be wrong. The carbs are at stock setting and the old air box is reinstalled. The mixture is 1 turn and the air is 1/1/2 turns open. The carbs were cleaned before this long process began, months ago. When I got the bike, over a year ago it was not in good shape. The first time I rode it on the highway I barried the throttle and it would only reach 50 mph, and of course it was not running very well, however better than it is now.

My questions are...

Can valve clearance problems cause...
1. no ability to idle?
2. slow starting?
3. when I twist the trottle, the bike bogs down and dies

Or could this be a combination of valve clearance problems and other things.

thanks

Scudder

 

[tom203]

Now that the 78 runs, I've got to work at getting the roughness out.

My questions are...

Can valve clearance problems cause...
1. no ability to idle?
2. slow starting?
3. when I twist the trottle, the bike bogs down and dies

Or could this be a combination of valve clearance problems and other things.

thanks

Scudder

Well sure! You been here long enough to know the drill- get the mechanical things in order ( esp. valve clearances) before you go fiddling with carb issues. Check compression to make sure it's reasonable, move on to potential electrical problems ( poor charging, etc ) and then turn your attention to the fuel delivery system ( petcock, fuel bowl levels, etc.). You said the carbs were cleaned- as dictated by the fussy folks here?
Do the long overdo maintenance and you'll have a reliable ride.

 

[Guest]

what tool are you waiting for to do the valve shims??

 

[Steve]

You don't need no stinkin' tool to do the valve shims.

Use the zip-tie method and get it done.

The only other "tool" you might find useful would be the one in my sig.

.

 

[Scudder]

Thanks again. The tool is a tappet depressor. Going to get started on it tomorrow.

Scudder