"I have twin Gen. IV 454 carbu
"I have twin Gen. IV 454 carburated Crusaders in a 1984 33 Egg Harbor convertable. The starboard engine won't turn up past 3200 RPMS; the port motor spins up past 4000 while dragging the starboard side along. Both props are 3-blade 19x20 in good condition. Problem has persisted since I took ownership 3 years ago. Compression check revealed cylinders 1 & 3 sharing compression (bad head gasket). Did head gasket job with Felpro marine gaskets; thought she was fixed but still won't turn up to rated RPM.
Noticed an occasional backfire through carb. around 2500 rpms. Found a bad lobe on camshaft; replaced camshaft with marine grind cam, lifters, and pushrods. No backfire now, thought she was good but still won't spin up. Replaced 20 year old distributor and coil with integrated unit from Davis Unified Ignition (DUI). Changed all plugs and wires. Set timing at 12 deg. BTDC and verified advance with timing light, all looked good but alas, no joy. This was last year so I think maybe I will check to make sure the advance is stil working (had a problem with the advance not working on a new DUI on port motor-sent it back to factory for repair-is good now but makes me wonder if the starboard side advance is hung up).
Floscan reports that the affected engine burns 25-40% more fuel than good engine, even when the good engine is turning faster! Fuel tank gauges confirm flowscan measurement. Fuel is fresh and stabilized and Fuel/Water filters were changed though they show no water and almost no particulates after a long run in heavy seas. Filter on engine changed and carb. filter cleaned. No change.
Compression was 124-127-119-122 for cylinders 1-3-5-7. This was after the head gasket job. Sorry no numbers for the outboard side (hard to reach).
Engine starts very hard compared to good port motor. Once strated, runs smooth and quiet at low speeds with no noticable misses, etc. Fuel flow at carb looks good (as expected from the flowscan values). Don't think its a fuel-related problem because it uses more than the other side. Carbs were sent out for cleaning/overhaul with no change.
Again, engine runs smooth and quiet at low rpms but won't turn up based on analog tachs and digital synchro.
Things I can think of checking are ignition advance (again), repeat compression check (all around this time), stuck choke (wired it open last year, no change), stuck valve? Could have internal engine damage, but head job revealed good looking cylinder walls.
She's giving me the finger and I'm about to write a check for a new one...."
"I have twin Gen. IV 454 carburated Crusaders in a 1984 33 Egg Harbor convertable. The starboard engine won't turn up past 3200 RPMS; the port motor spins up past 4000 while dragging the starboard side along. Both props are 3-blade 19x20 in good condition. Problem has persisted since I took ownership 3 years ago. Compression check revealed cylinders 1 & 3 sharing compression (bad head gasket). Did head gasket job with Felpro marine gaskets; thought she was fixed but still won't turn up to rated RPM.
Noticed an occasional backfire through carb. around 2500 rpms. Found a bad lobe on camshaft; replaced camshaft with marine grind cam, lifters, and pushrods. No backfire now, thought she was good but still won't spin up. Replaced 20 year old distributor and coil with integrated unit from Davis Unified Ignition (DUI). Changed all plugs and wires. Set timing at 12 deg. BTDC and verified advance with timing light, all looked good but alas, no joy. This was last year so I think maybe I will check to make sure the advance is stil working (had a problem with the advance not working on a new DUI on port motor-sent it back to factory for repair-is good now but makes me wonder if the starboard side advance is hung up).
Floscan reports that the affected engine burns 25-40% more fuel than good engine, even when the good engine is turning faster! Fuel tank gauges confirm flowscan measurement. Fuel is fresh and stabilized and Fuel/Water filters were changed though they show no water and almost no particulates after a long run in heavy seas. Filter on engine changed and carb. filter cleaned. No change.
Compression was 124-127-119-122 for cylinders 1-3-5-7. This was after the head gasket job. Sorry no numbers for the outboard side (hard to reach).
Engine starts very hard compared to good port motor. Once strated, runs smooth and quiet at low speeds with no noticable misses, etc. Fuel flow at carb looks good (as expected from the flowscan values). Don't think its a fuel-related problem because it uses more than the other side. Carbs were sent out for cleaning/overhaul with no change.
Again, engine runs smooth and quiet at low rpms but won't turn up based on analog tachs and digital synchro.
Things I can think of checking are ignition advance (again), repeat compression check (all around this time), stuck choke (wired it open last year, no change), stuck valve? Could have internal engine damage, but head job revealed good looking cylinder walls.
She's giving me the finger and I'm about to write a check for a new one...."