I have a new to me boat with a 1984 OMC 3.8l V6 with a 2BBL carb and points ignition. I've never had any experience with boats, but have spent lots of time messing with Hondas and tractors. I've been lurking here for a month now and have read most of the "OMC won't start / Timing / fuel" threads.
When I got the boat, it had been sitting for 5 years uncovered, so everything inside was corroded and none of the electricals were working.
I've done the following.
I put the muffs on it last night and tried to get it to start. It turned over well enough (seems a bit slow, but never worked on this large an engine before), backfired once right away, but never really tried to run. I removed the flame arrestor and could not see any fuel coming in. I was on my own, so had no assistant to crank it while I watched (for the eyebrow singing backfire) in the throat, but it looked wet down below. I tried pouring a couple of tablespoons in the throat, but no difference.
A few questions
Is there any way to advance the throttle while trying to start? The interlocks only seem to allow the starter to work with the lever vertical.
Where do I turn next? Do I dig into the carb, or do I get a timing gun and dwell meter and verify the timing (as opposed to just the points gap)
I have not done a compression test on the engine. How crucial is that? I expect it should at least fire on some even if one or two cylinders are bad.
How do I verify that the fuel pump is doing its job and getting the fuel to the carb? This is a mechanical pump that appears to be driven off the engine.
Sorry about the long winded post. As I said - I'm new to boats and V6 engines, but my wife and kids are pressuring me to get out on the water before it gets too cool and we need to be winterizing it instead, so looking for some help. Getting it running is a higher priority than making it perfect. Unfortunately neighbourhood mechanic friend moved to North Carolina, so I can no longer rely on him to steer me in the right direction.
When I got the boat, it had been sitting for 5 years uncovered, so everything inside was corroded and none of the electricals were working.
I've done the following.
- Checked and cleaned all the contacts and wires, and now have all the trim motors, lights and switches working properly.
- Freed up engine by removing plugs and using oil in the cylinders. Engine now turns over easily with a breaker bar. Not freely, but not difficult either.
- Replaced old battery with brand new 1000amp marine battery, and keep it charged when not working on boat.
- Removed and rebuilt starter and solenoid, as initially it was just clicking.
- Removed and cleaned and regapped points. Verified firing order and spark plug wires, and verified nice strong spark at each plug. Changed plugs out.
- Freed up the throttle cable linkages and choke linkages and ensured that everything seems to be operating normally.
I put the muffs on it last night and tried to get it to start. It turned over well enough (seems a bit slow, but never worked on this large an engine before), backfired once right away, but never really tried to run. I removed the flame arrestor and could not see any fuel coming in. I was on my own, so had no assistant to crank it while I watched (for the eyebrow singing backfire) in the throat, but it looked wet down below. I tried pouring a couple of tablespoons in the throat, but no difference.
A few questions
Is there any way to advance the throttle while trying to start? The interlocks only seem to allow the starter to work with the lever vertical.
Where do I turn next? Do I dig into the carb, or do I get a timing gun and dwell meter and verify the timing (as opposed to just the points gap)
I have not done a compression test on the engine. How crucial is that? I expect it should at least fire on some even if one or two cylinders are bad.
How do I verify that the fuel pump is doing its job and getting the fuel to the carb? This is a mechanical pump that appears to be driven off the engine.
Sorry about the long winded post. As I said - I'm new to boats and V6 engines, but my wife and kids are pressuring me to get out on the water before it gets too cool and we need to be winterizing it instead, so looking for some help. Getting it running is a higher priority than making it perfect. Unfortunately neighbourhood mechanic friend moved to North Carolina, so I can no longer rely on him to steer me in the right direction.
