25hp chrysler - cough, smoke, no idle

[simpsonian]

I bought a used boat and with a 1976 25 hp Chrysler electric start and was told it hadn't been run in a few years but was running fine before. I'm a novice at outboards so I appreciate any help you guys can give.

I bought a manual and replaced the fuel line and tested the fuel pump and that's all working fine. Was getting no spark so 2 nights ago I cleaned the breaker points and got ignition! The motor fired up and ran but would cough at regular intervals (about once every 3 seconds). This caused it to stall at neutral but at full idle it would recover and run for awhile. I have it in my large bin with water and the tail is pushing water out but it seems to be running overly hot to me.

Last night went out to tinker some more but it would not even run for more than 10 seconds. Lots of smoke and the engine would start but die pretty quickly and occasionally jerk / stall and exhaust a bunch of smoke and water. Would it run differently in the lake or would that be a better place to see if I could get it running? Can I try and put it in gear in a tub of water? It didn't seem like a good idea to me.

Thanks for your help. I'm gearing up to really work on it this weekend.

 

[MikDee]

Re: 25hp chrysler - cough, smoke, no idle

First thing you better do, is put a new water pump impeller in the lower unit, and check the thermostat, if it's running hot like you say,,, then don't run it without water. Next, make sure to set your points to the right gap. The carbs are probably gunked up with old bad gas, you might want to spray some deep creep into the carbs if you can keep it running long enough.

Here you go, read this it'll help you out: http://forums.iboats.com/showthread.php?t=158086

 

[Frank Acampora]

Re: 25hp chrysler - cough, smoke, no idle

Get it right in the driveway first! If it doesn't run correctly at home, it will only be worse on the lake and you will be kicking yourself for wasting the time to drive to the water. Plus, you will be under the gun to get it to run and will make misteaks (mis-spelled on purpose)

 

[simpsonian]

Re: 25hp chrysler - cough, smoke, no idle

Thanks - I took the flywheel back off and cleaned and reset the breaker points. Ended up working fine - very little smoke and a good idle. I replaced the impeller after that since it was running so hot the other day but now that I've put it back together it seems I have changed the neutral point so I'll be trying to adjust that tonight.

Before replacing the impeller it was running really well, although hot, so hopefully she should be good after tonight.

 

[simpsonian]

Re: 25hp chrysler - cough, smoke, no idle

So I have a new problem. I got it running great the other day on the lake but it was running hot. I brought it home and replaced the impeller (the old one was obliterated) and when I put it back together I had trouble keeping it alive. It would roar to life for about 2-5 seconds and then die out. After 30 minutes of messing with the idle screw and fuel connections / pump I realized that I had not opened the gas tank vent (yes - I'm a moron).

I opened the gas tank vent but the engine would not even start. I tested the spark plugs (great spark), the gas pump (great pressure) and everything seems to be working fine but still no start. the spark plugs have some gas residue on them so gas is getting into the cylinders and they spark but the engine will not start. the only other thing i noticed is that gas is dripping out of 2 small holes in the upper gearcase.

What is going on and how do I fix this? (should this be a new post?)

 

[eurolarva]

Re: 25hp chrysler - cough, smoke, no idle

Re check your timing. If you did not torque the flywheel enough you probably sheared the key. Torque should be 80 ft lbs.

Running with the vent closed can cause the diaphram to burst in the fuel pump. You might want to open it up and see if it is intact. Also check the check valves in the pump.

If motor overheated and shut down last time you ran it do a compression test. My guess is the key is fried though.