Emgine running away

Hello. 82 Yamaha xj750. Just rebuilt carbs, been synced and set needle valves for a generic setting

 

And, what? It's idling too high? Or hanging high when you let off the throttle?

Have you checked basic things, like the throttle cable is correctly routed, lubricated, and moves freely?

Did you replace throttle shaft seals while overhauling the carbs?

What effect does the idle adjustment screw have?

 

it seems to stick even though i check to make sure the throttles are closed.
ok thanks for the advice.
New shaft seals, cable is like new and properly adjusted, butterflies snap closed. I was just wondering if anyone else came across this issue with carburetors that are not 100% synchronized. I have the gauges coming in a few days. I just started it up today and figured I would ask around.
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Hanging high not sticking sorry

 

Oops I was talking about. air fuel mixture needle valves. set to 2.5 turns out each. But like I said I won't properly adjust them until I get my vacuum gauges. Thanks

 

What condition are your intake boots ? Are you running the stock airbox or PODS? A hanging idle can be a vacuum leak . The other possibility if you di the butterfly seals your plate may not be perfectly centered .

 

Synch issues will normally make the idle lumpy, not make anything hang high.

Did you remember to put the vacuum caps back on and connect the vacuum line to the petcock?

Hanging high could also be too lean, which shouldn't be the case with 2.5 turns out. You could try giving it a bit of choke (enrichment) and see whether that helps.

 

thank you

 

thanks