1984 merc 150 problems after warming up

" I have been trying for 2 sea

" I have been trying for 2 seasons to correct a problem that the motor is having. It runs perfectly for aprox 15 minutes until it is up to full temperature. Then it acts as if the fuel system and/or ignition is failing. I have rebuilt the carbs and fuel pump. I also replaced one of the ignition power packs after finding intermittent firing on 1 bank of cylinders. I have a fuel/water separator installed and have replaced all of the fuel supply lines and fittings. I tested the stator and trigger using an ohm meter and the service manual data and all seems fine with the engine cold. Even when it is warm and running very poorly (dies at idle, stalls when accelerating, seems to be flooded but if I tap the choke and work the throttle I can usually keep it running) it will still run good at wot if I can work it enough to get on plane. Fuel bulb is full and pumping it makes no difference. Is it possible that the stator or trigger (or even coils) are having problems only after reaching higher temperatures? If so, is there a way to test this without purchasing additional test equipment?
I checked compression and all cylinders are between 104 and 110 lbs cold.
Any advice would be greatly appreciated.
Thanks "

If you can choke it and keep

If you can choke it and keep it running then flooding isnt the problem..I would bet on ignition problems or in worse case a vacuum leak carb gasket or crankseals or case leak..

" Thanks for the reply, I feel

" Thanks for the reply, I feel that I have some type of heat dependent ignition problem. The motor seems to run great for a limited time until it reaches full temperature. I have checked fire on all cylinders at home while the motor is relatively cold (running on muffs, no load), and I did find that I had a suspect power pack that was intermittently losing fire to cyl 1 and 5. I swapped packs and the problem followed to cyls 1 and 6 so I replaced the pack. This did not correct the on the water problem after warming up. Is there any specific ignition component that would be suspect after reaching temperature? I have read that a bad rectifier could cause this type of problem. I do not have a way to test the system while at the lake. As I mentioned earlier, all ohm tests were within specs at home. Maybe it is a coil problem as well.
Any suggestions or similar experiences/resolutions would be appreciated.
Thanks "

" I was having a similar probl

" I was having a similar problem with an 82 model 150 merc. My motor would run perfect until it had a chance to warm up real good, maybe 10 or 15 minutes. Then it would fall on its face and not do anything above an idle. My mechanic found the stator was bad causing damage to my power packs. This would only show up when the motor was hot. I replaced the stator and power packs and it ran fine after that. It was expensive but that fixed my problem. I'm not an expert but your problem sounds similar. Good Luck "

" I appreciate the info, I tal

" I appreciate the info, I talked to a mechanic yesterday and he suggested the same possibility. He said that even though the stator is testing fine on the ohm test, he suspects that the low speed windings are failing after getting warm. He indicated that since my problem was a low speed one (mine will still run great on top end if I can work it enough to get the rpm's up past 3000 or so), he felt that the stator is failing once warm. I am considering replacing it myself instead of having the shop do it. It has been a very frustrating thing to try to track down. Hope fully this will take care of the problem. Thanks again for the advice and I will post if it cures the problems (may help someone else in the same situation).
Kip "