Delay due to computer crash.
The problem with the engine turned out to be crud in anti-siphon valve. Running fine now, but will look for an in-tank pickup with good screen.
Runs 5 min @ 3300 then quits as if key turned off. Restarts but only runs at idle. No water in fuel, new pickup tube and antisiphon valve, no pump whine.
Engine runs at 3300 for five minutes or so, then quits as if key turned off. It then restarts but will run only at idle, and quits now and then at idle. Next day does the same.
By the time we got it running correctly at the dock, time ran out to winterize the boat. So, although we're confident it's fixed, we haven't yet gotten a cruise or top end test. In the Spring, I'll post results.
Scott & Bondo:
Thanks a lot for your help. With better understanding what we are dealing with, I think it's fixed. My basic misunderstanding was how early the advance mode comes in. It adds 10 degrees in the idle range starting at 500 RPM. In about 60 years of messing with advance, I'd always...
I am not ignoring what you posted, but I agree that I don't understand how base mode works. I appreciate your help. My probably incorrect understanding was that base mode inactivated the advance program built in to the module, thus letting the initial zero-advance timing be set. I expected that...
Will be getting a battery, but when it is 12 degrees at base mode, and then max of 32 in run mode, the advance at idle is 24-26 degrees. despite base having been set at 12.
We have a 1985 Tiara 31 with dual 454 carbureted Crusaders. Most history is unknown. Starboard engine has a United GM EST Distributor kit. (Port ignition is different system.) We have been unable to get spark advance to behave properly. The United instructions prescribe base timing setting at 12...
