billet flywheel and timming on engine


New member
A completly noob question.

I instaled and billet flywheel and sparks plug get really dry dark after some laps engine bogs at low rpm until it fails.

What is normal degree timming on a gx390? i have a 6 degree key installed.

my engine has stock crank, modified cam, 30 mm carb with big air filter, harder springs, rpms are prob 6000.

The flywheel already has 24 degree with stock key, should i change key to stock or just change carb low jet to a smaller one.

Thanks alot.

95 shaw

Site Supporter
What is actual timing?
Is cam timing correct?
Verify cam and ignition timing first.
Degree wheel.

Most have trouble getting enough fuel to get off idle to get on main circuit.

Too cold a plug on gas can be problematic, especially with idle times.

Just some thoughts.


New member
When i installed key the image on instructions said the notched part should be to the left, that means im changing the timming, from 26 .º to 20.º. Prob i should install the stock key and get 26.º.

Ill verify everything again. Thanks.


Dawg 89
Nope thats right .
the flywheel turn too the right if you move it forward to the right thats advancing it .
visualize the piston at the top tdc with out piston movment . then the flywheel turning forward or back.
ahead of the piston or behind the piston .