Advanced timing how much is too much

[olajoe808]

30-32, 32-34, etc..... at the key. Is there a correlation (inverse/direct) between hp/torque and the amount advanced?

 

[minidragbike]

Need more spec's
Cam, compression, alky, gas, etc

 

[olajoe808]

Need more spec's
Cam, compression, alky, gas, etc

Don't have specifics, just a general question for future planning. if the timing needs to be advanced in the future I might need to start practicing up on making my own keys.

 

[boogyman]

The most common I see done, with a built 6.5 is a 8 degree key. That means you have to file .048 off of it. And that is for a gas gx200/clone motor.

 

[minidragbike]

Like I said it all depends on what is done to the motor.

Most cams comes with a timing to start the motor at. The reading is usually for running methanol in the motor, so usually gas is about 4 degrees less then the alky recommendations.

If the motor is stock, or govenor removed, or pipe and re-jetted the #8 key will be to much timing for it. That will put you up in around 29-31 degrees area.

A briggs world formula race motor at 15hp only runs 28 degrees on 93 octane gas.

 

[HomerB]

How much timing advance is too much when Propane is being used as a fuel and the head has been milled down?

I just ordered a #9 timing offset key for my 3.5HP vertical shaft Briggs & Stratton.

Homer

 

[Richard Trotter]

Doesn't altitude figure into the timing, too?

 

[65ShelbyClone]

You have too much timing when power starts dropping off. You definitely have too much timing if the engine is pinging.

Like MDB said, it depends very much on the parts combination, fuel, air:fuel ratio, etc. Vague questions get vague answers.

Doesn't altitude figure into the timing, too?

Yes it does. Higher altitude means thinner air, lower cylinder pressures, and more ignition advance.