another dumb propane question

[wanabecruisen]

OK - I got my propane set-up installed and running but have one more question. On the Impco 425 mixer, where do you get your vacuum advance for the distributor? All the available ports are on the Q-jet base and I thought it needed to be above that??? Any suggestions? Thanks.

[peesalot]

IIRC the ones on the Q JET are usable. Just put the meter on and see what they pull.

[freds40]

I've always used the base plate on gas motors. I am using a 450 x mixer for my LPG and I am using the baseplate. When the engines running, pull a plug off each port 1 by 1 and just feel which has no vacuum @ idle. You can stick your finger over it or just listen to the motor. Full time vacuum will cause the motor to lug down or stall and no vacuum @ idle will not change the sound of the motor. You want a port that has no vacuum @ idle as the advance will increase with the increase of engine rpm/vacuum.

[wanabecruisen]

Thanks guys. I tried a baseplate port that had no vacuum at idle and some (don't know how much as I have no gauge) at rpm but it didn't seem to give much advance. I may need to check this distributor for correct function. Any helpful hints? Thanks again.