SeanMcl
Petty Officer 2nd Class
- Joined
- Apr 3, 2009
- Messages
- 187
Just a post for posterity. Hope this helps someone else out.
The boat: 1974 Gulfstream, OMC 190 I/O. Has not been run in 6 years. Kept in indoor storage.
The pregame warm up: Pulled the spark plugs, put some oil in there, turned motor over by hand to make sure it's moving OK. Pulled the distributor, spun the oil pump with a drill for a minute or so. Gas tank was full of 6 year old gas, put two bottles of octane boost and a bottle of Sea Foam in it, changed the fuel filter, crossed my fingers. Put in a new battery. Checked oil levels in intermediate, upper and lower gear cases, had milky oil in the upper, drained and refilled upper case. Tuned on blower and bilge pump, both run.
Initial issues: Engine will not start.
Fuel leaking from carburetors accelerator pump gasket. Carb is a Holley 2bbl, list number is 6317-1. I can find almost no info on this carb on the net. I order Holley rebuild kit 703-30, which turns out to be wrong, 3-888 is the correct one, but I don't know that yet.
The distributor is in bad shape, a Prestolite IBM 7007S-11G. The local marine shop has a new cap, rotor, points and condenser for it though.
Now the engine starts, and seems to run fine. Take a quick trip to the nearest lake.
Secondary Issues: It doesn't want to start on the lake. After a couple shots of starter fluid, it fires up and runs OK. There is a major hesitation when the throttle is punched, but other than that it's good. After about 3 hours the engine kills while cruising at about 1/2 throttle. Restarts fine, then kills every 2 minutes or less on the way back to dock. Putting in a spare fuel filter did not help.
Came home, drained old fuel. Filled up with 91 octane and a bottle of carb cleaner. Next trip to the lake I have the same issues. It will run for up to 1/2 hour OK, then back to stalling every 2 minutes.
Thinking I still have carb trouble, I call Holley tech support and find I have the wrong renew kit in it. My carb is a 300 CFM 2 bbl specifically for the marine Ford 302. Put in the correct renew kit (3-888), also find clogged accelerator pump nozzles that I missed the first rebuild. Run back to the lake, and now it is running really well... for about 2 hours.
Third Set of Issues: The stalling is back, same as before. No acceleration bog though, which is good. I unscrew the fuel level plug in the float bowl, and it's dry in there. Must be the fuel pump, I think. No fuel in the pump's sight bowl, though, which I would expect if the pump had failed. Puzzled.
Come back home, buy a new fuel pump ($165? Yikes!), start searching the iBoats forums for fuel pump issues, and find an excellent article on troubleshooting fuel delivery issues with a a vacuum/pressure gauge.
I build a setup like is pictured in the article, place it between the fuel pump and the carb, and it slowly builds pressure to 3.5 lbs. Too low, looks like a bad fuel pump, I think. Then I put the gauge between the fuel pump and the gas tank to measure vacuum and it pulls over 21 inches of Hg! Wow, that's a bit high. I remove the pickup tube in the gas tank, and the screen is clogged so bad I can barely blow through it. When I try cleaning the screen it disintegrates, so I cut off what is left. I soldered some brass screen from a hose fitting back on the tube. I also put an additional fuel filter inline between the tank and the fuel pump because now I'm paranoid about gunk in my tank. I also replace all the fuel line from the tank to the carb. It was only about 6 feet, so not a big deal.
So I hook everything back up, and even with the additional fuel filter the vacuum gauge is pulling 2 inches of Hg. Fuel pressure is reading 5 psi. Fuel float level on the carb is proper. A quick trip out to the lake and all is running fine. Throttle response is improved as well. Knock on wood, I am calling the stalling and acceleration bog fixed.
4th Issue: Water in the upper gearcase oil. I took the boat to a mechanic for a new upper gearcase seal kit. Turns out that it's possible for water to get trapped in the impeller even with the outdrive down. The trapped water froze blowing out a couple seals in the impeller housing and buckling the plate the water pump impeller sits on. He replaced the impeller and plate, and put in the seal kit. Pressure tested it and everything held. He told me to unplug the ignition coil and then to spin the motor once with the outdrive down before storage and that would clear any trapped water out of the impeller housing preventing this kind of thing in the future.
I also found out that a bilge pump can run, but still not be able to pump any water. I replaced that too.
The boat: 1974 Gulfstream, OMC 190 I/O. Has not been run in 6 years. Kept in indoor storage.
The pregame warm up: Pulled the spark plugs, put some oil in there, turned motor over by hand to make sure it's moving OK. Pulled the distributor, spun the oil pump with a drill for a minute or so. Gas tank was full of 6 year old gas, put two bottles of octane boost and a bottle of Sea Foam in it, changed the fuel filter, crossed my fingers. Put in a new battery. Checked oil levels in intermediate, upper and lower gear cases, had milky oil in the upper, drained and refilled upper case. Tuned on blower and bilge pump, both run.
Initial issues: Engine will not start.
Fuel leaking from carburetors accelerator pump gasket. Carb is a Holley 2bbl, list number is 6317-1. I can find almost no info on this carb on the net. I order Holley rebuild kit 703-30, which turns out to be wrong, 3-888 is the correct one, but I don't know that yet.
The distributor is in bad shape, a Prestolite IBM 7007S-11G. The local marine shop has a new cap, rotor, points and condenser for it though.
Now the engine starts, and seems to run fine. Take a quick trip to the nearest lake.
Secondary Issues: It doesn't want to start on the lake. After a couple shots of starter fluid, it fires up and runs OK. There is a major hesitation when the throttle is punched, but other than that it's good. After about 3 hours the engine kills while cruising at about 1/2 throttle. Restarts fine, then kills every 2 minutes or less on the way back to dock. Putting in a spare fuel filter did not help.
Came home, drained old fuel. Filled up with 91 octane and a bottle of carb cleaner. Next trip to the lake I have the same issues. It will run for up to 1/2 hour OK, then back to stalling every 2 minutes.
Thinking I still have carb trouble, I call Holley tech support and find I have the wrong renew kit in it. My carb is a 300 CFM 2 bbl specifically for the marine Ford 302. Put in the correct renew kit (3-888), also find clogged accelerator pump nozzles that I missed the first rebuild. Run back to the lake, and now it is running really well... for about 2 hours.
Third Set of Issues: The stalling is back, same as before. No acceleration bog though, which is good. I unscrew the fuel level plug in the float bowl, and it's dry in there. Must be the fuel pump, I think. No fuel in the pump's sight bowl, though, which I would expect if the pump had failed. Puzzled.
Come back home, buy a new fuel pump ($165? Yikes!), start searching the iBoats forums for fuel pump issues, and find an excellent article on troubleshooting fuel delivery issues with a a vacuum/pressure gauge.
I build a setup like is pictured in the article, place it between the fuel pump and the carb, and it slowly builds pressure to 3.5 lbs. Too low, looks like a bad fuel pump, I think. Then I put the gauge between the fuel pump and the gas tank to measure vacuum and it pulls over 21 inches of Hg! Wow, that's a bit high. I remove the pickup tube in the gas tank, and the screen is clogged so bad I can barely blow through it. When I try cleaning the screen it disintegrates, so I cut off what is left. I soldered some brass screen from a hose fitting back on the tube. I also put an additional fuel filter inline between the tank and the fuel pump because now I'm paranoid about gunk in my tank. I also replace all the fuel line from the tank to the carb. It was only about 6 feet, so not a big deal.
So I hook everything back up, and even with the additional fuel filter the vacuum gauge is pulling 2 inches of Hg. Fuel pressure is reading 5 psi. Fuel float level on the carb is proper. A quick trip out to the lake and all is running fine. Throttle response is improved as well. Knock on wood, I am calling the stalling and acceleration bog fixed.
4th Issue: Water in the upper gearcase oil. I took the boat to a mechanic for a new upper gearcase seal kit. Turns out that it's possible for water to get trapped in the impeller even with the outdrive down. The trapped water froze blowing out a couple seals in the impeller housing and buckling the plate the water pump impeller sits on. He replaced the impeller and plate, and put in the seal kit. Pressure tested it and everything held. He told me to unplug the ignition coil and then to spin the motor once with the outdrive down before storage and that would clear any trapped water out of the impeller housing preventing this kind of thing in the future.
I also found out that a bilge pump can run, but still not be able to pump any water. I replaced that too.
