82 750 maxim lean rev

This has been driving me nuts,

Some history on the bike, I bought it last July, with just under 8000 miles. The guy said it was sitting in a barn before he bought it for who knows how long. The tank was rusted out, he put new one on. The carbs were also in need of a cleaning. He only put 800 miles or so on it.

It always had a lean rev when i bought it. I found the intake manifold gaskets were bad, replaced those. This helped a little, but didn't cure it. I then found that the throttle shaft seals were leaking/missing. Put new V seals in, helped more but didn't cure it. At this point, when cold the bike would run fine. Once it warmed up it would act like its suppose if you kept the revs under 3000 rpm, once it got over 3000 rpm, it would do a lean rev to 6000 rpm.

Fast forward to now, I got the bike out for the spring. had a weird miss at idle. Also once you touched the throttle it would rev to 6000 rpm. Just taking the slack out of the cable and a hair more is all it would take to rev. I decided to take the carbs off, took them apart and the bowls were grungy and the choke port it the bowl was completely plugged (now the choke work properly). I cleaned every nook, cranny, and port in the carbs. Diaphragms look very good, went through everything on the carb, i couldn't find anything wrong with them. I put them back on, it no longer has the weird miss. It went back to the over 3000 rpm rev. I sprayed carb cleaner everywhere around all carbs, intake, everywhere, no vacuum leak at idle. I pulled the cam cover, all the valve clearances are in spec.

I don't know what else to check.

 

if valve clearances are good and there are no intake leaks then the next steps would be bench sync your butterflies, wet set your fuel levels to get it to run long enough to vacuum sync it.

 

When you pull the throttle, does the cable get hung up anywhere?

 

Before I put the carbs back on the bike the last time, I did bench sync them. I need to get a YICS block off tool yet to vacuum sync them.

The throttle cable is good, does not hang anywhere. No kinks, smooth operation.

 

No you don't need the YICS block-off tool to sync. You'll be darn close enough without it.

Are you SURE jets are all in their correct spots?? Mixing some of the up can do that too, but it seems you still have a leak.

Carb to manifold boots each end
Manifold nipples
Throttle shaft seals
Wrong placement of jets
Wrong size jets
Unbalanced carbs
Too lean on the mixture screws
Missing airbox
Missing filter
Pods?

All things to double check