Port Engine Power Loss

[Big D]

If everything ran fine once you hooked up the portable tank, why would you replace the carb?

[prowlersfish]

If everything ran fine once you hooked up the portable tank, why would you replace the carb?

I agree ( of course this is from the guy said check the filter in the carb ) (post without seeing that )

[ready123]

Ask them to bring timing lights to check your advance as you throttle up....

[ready123]

If everything ran fine once you hooked up the portable tank, why would you replace the carb?

I know, certainly sounds like it is a fuel supply problem..... Maybe he just wants to renew/fix everything else first

[djmair]

Okay, just an update:
Swapped out the carbs and electronic ignitions, put new pickup tube in tank Timing was checked and went out for a run.
Got up to 3200 revs for about 15 mins and port engine again started to fall off. When you tried to throttle back up she started to back fire. She finally stalled and came back in on trusty starboard. Plenty of fuel in the carb so I think the gas and carb are not at issue. Could this be an exhaust issue, or something overheating electric system?

[Big D]

What did the two mechanics say??

[djmair]

Only one mech on board. Scratching head, nothing seems out of order, no idea what is wrong.

[dfg4240]

Timing chain

[djmair]

Checked this last year but will give it another look as the symptoms seem to be getting
worse

[dfg4240]

Sorry-I didn't see where it ran ok with a portable tank.
Timing chain has other symtoms also like rough idle and intermittent stopping, power loss and valve noise.
I know this has nothing to do with it but my daughter had a hyundai which ran great and then lost power and slow down and she would have to pull over off the road and shut it off for awhile-it would run again for a short while and then do the same thing again.It turned out to be a resistor in the electrical circuit of the fuel pump after going to a mechanic three times (Towed).
The resister would open up when hot.
dfg4240

[ready123]

Okay, just an update:
Swapped out the carbs and electronic ignitions, put new pickup tube in tank Timing was checked and went out for a run.
Got up to 3200 revs for about 15 mins and port engine again started to fall off. When you tried to throttle back up she started to back fire. She finally stalled and came back in on trusty starboard. Plenty of fuel in the carb so I think the gas and carb are not at issue. Could this be an exhaust issue, or something overheating electric system?

New pickup tubes... was anti-siphon valve in bend opened and cleaned?
When you ran on the portable tank did you run it as long as the above? If YES then we need to look closer at fuel pickup/anti siphon valve IMO.
If you did not run as long on the portable then one cannot use that as a pass for the close to engine items as we have been doing..... so have you used a timing light to see if the adv/retard may be failing at that time? Sticky weights on the distributor?

I still lean to the fuel supply symptom side of things..... pickup or carb float? If the portable tank run was long then I will have to back off that idea.
I had blocked anti siphon that caused me the same angst till I found it.

[larryeddington]

What was the result of sea trials?

[Cmount]

I did have a similar problem last year. My hunch was a carb issue. I changed it out and am back to full RPMS. I felt it had something to do with the secondaries as I was good to about 3000 and then it dropped as I tried to go higher. Now with my gas flow meters I am confident that right around the 3000-3100, the secondaries open as I go from 22 GPH to 33+++GPH... Hope the carb is the fix. It was for me. Purchased fully recon'ed units from AllState in Long Island.

[dfg4240]

I apologize to you for some of the things I said to look for.
I read your whole post and realize now that you said everything ran fine with a separate fuel supply so forget the engine and it is from the tank to the carb intake.
For me it would mean that if they both run on the same tank then it means where the line splits and goes to the port engine and the other to the starboard engine is where the problem is.
Thats what I would think and I know it sounds crazy but I would take from where it splits and connect the starboard side line to the port engine carb and run it .
If it runs right then replace as needed.sounds like she is getting fuel ok at idling but starving as the rpm goes up
almost like vapor locking. Funny how it ran ok with a separate fuel supply and that would tell me the engine is ok.
If I am wasting your time I apologize to you and wish you good luck on this expensive problem.
dfg4240

[Scorpion07]

I had the identical symptoms with my F32. As time went on I realized it always happened at a certain time interval. About 20 minutes. I Repaired/replaced the carb, distributor, fuel line, anti siphon valve, fuel filters...... To no avail. All along looking for fuel starvation problems because that's what it seemed like.
Long story short, It turned out to be my blowers. I replaced them with Rule low amperage inlines because they were squealing and definitely had noticibly less draw on my motor when they were turned off. It hasn't done it since.
Now this all happened with my starboard engine, but on my F32 the starboard battery is also the house. Perhaps yours is different.
Talked to my salty neighbors over the months and they were stumped. One, an electrical engineer, didn't know why that would eliminate the problem. He said if it solved the problem there's no denying the solution though.
In any case, you should probably move onto an electrical diagnosis though. Especially since you have a new fuel system now. Chase your wiring and electrical components before you buy a new carb.
Hope this helps.