Bike not running right 750 twin

Got this bike a couple weeks back and it never ran right. 83 750 LTD twin

no power past 4500 rpm and not enough before. All stock aside from uni filter

New plugs
Coil mod done
Advancer checked (moving freely but how do I check proper function?)
Carbs synced
rejet to 119, no change
rejet to 133, no change
Left side float is in spec at 5.5mm Right side is too high at 0
Plugs look lean, no carbon

So after all that I haven't made any progress. Any tips? I'm getting pissed lol

Thanks

Are all valve clearances within specs?
Too tight valve clearances often cause loss of compression as the engine attains operating temperatures.

Check advancer with a strobe type timing light while engine's running without the points cover by watching timing marks through the inspection window and seeing them move quickly back and forth as they're supposed to when rpm is varied by blipping the throttle.

Good Fortune!

And would suggest not worrying too much about "float height," which isn't the critical factor, and is notoriously unreliable when used alone as a means toward achieving the correct fuel level.

The critical factor is FUEL LEVEL inside the float bowls.
And the most reliable method of assuring correct fuel is via the clear tube test.

Stated another way, proper float height is whatever it takes to result in the correct fuel level.

Good Fortune!

I used the tube test to determine what I did, just haven't adjusted them yet.

Compression was within spec at full running temp but I haven't had the cover off yet to check clearances

Also My bike is an 83 with electronic ignition so the timing check you described won't work I believe

Tony208 wrote: I used the tube test to determine what I did, just haven't adjusted them yet.

Compression was within spec at full running temp but I haven't had the cover off yet to check clearances

Also My bike is an 83 with electronic ignition so the timing check you described won't work I believe

used the tube test to determine what I did, just haven't adjusted them yet -- It's adjustment time.

Compression was within spec at full running temp -- pretty neat trick doing that test. :woohoo:

haven't had the cover off yet to check clearances -- It's adjustment time.

bike is an 83 with electronic ignition so the timing check you described won't work I believe -- the idea here is not checking the timing, but to assure functioning of the automatic advancer.
Could be mistaken, but thinking the bike at hand has a typical timing inspection window through which function of the advancer may be observed under a strobe type timing light while the engine is running.
Must remove the "points cover" to see through the timing window.

These images are different from the bike at hand, but should be similar enough to illustrate viewing marks on the advancer through the inspection window.








Good Fortune!

Lots of good info on kawasaki.com, including parts diagrams, part numbers, models sharing same part, availability, etc.

Here's a link for help with navigating the site and finding information.

kzrider.com/index.php?option=com_kunena&...w&catid=13&id=376734

Good Fortune!

Tony208 wrote: I used the tube test to determine what I did, just haven't adjusted them yet.

You are probably flooding on the high one. These carbs are very sensitive to getting the fuel levels just right.

Definately not flooding, both plugs are showing lean. Guess its time to tear in to it instead of riding it

Are you using pods or the stock airbox?

Tony208 wrote: ...Plugs look lean, no carbon....

bountyhunter wrote: ...probably flooding on the high one. These carbs are very sensitive to getting the fuel levels just right.

Tony208 wrote: Definitely not flooding, both plugs are showing lean. Guess its time to tear in to it instead of riding it

Flooded plugs won't show carbon.
Might be failure for whatever reason of fuel mixture to reach the combustion chamber.
Could be a carb issue or a fuel supply issue.

time to tear in to it -- perhaps, but imo not yet warranted from the information and history furnished to date. But would at least be educational.

In any event, should perform a leak-down test, especially before removing the head.
Otherwise risk later adding "top end overhaul" to the "already done" list and still having the same problems of "not running right" and becoming even more frustrated.

Good Fortune!

By tear in to it I meant check valve clearances. Need to fix the valve cover leak anyway. Guess I'll adjust the float level and see what happens. In my experience the plugs are wet when its flooding and it won't idle without dying

Tony208 wrote: Definately not flooding, both plugs are showing lean. Guess its time to tear in to it instead of riding it

By floding, I meant the fuel level in the "0" bowl is way too high and maybe even high enough to send some gas out the overflow pipe. Believe me when I say, that fuel level is CRITICAL. On BS-38 Mikuni, it's spec is 4.5 - 6.5 mm from the upper edge of the float bowl. On mine, one carb was maybe one mm too high and it ran like crap, wouldn't idle right. Set them both at 5mm and see if some of your problems go away. Regardless, setting the fuel levels right is ALWAYS the first step in adjusting or syncing carbs because it affects all the other adjustments.