1978 Evinrude 140

[tmcallister]

I am in the middle of doing a complete restoration of a 1978 Glastron SSV-176. Last night it was time to fire up the engine...for the first time. The engine started...but runs really rough and sputters. It will only idle with lever fully up position. The previous owner replaced one of the power packs..with one for a lot newer engine. I really dont know where to start with this. Whether it might be timing issue or carb...or the power packs.

 

[crb478]

Re: 1978 Evinrude 140

I would start with the basics and get compression numbers for all four cylinders, keep them or write them on the heads for future reference.You are looking for over 100psi and within 10% for all cylinders. Then Verify that you have a strong blue spark tha will jump a 7/16 inch gap on all four cylinders. This would be a good time to replace the impeller or the whole water pump kit as long as the motor seems mechinically sound from the above test. Once you have that done then verify that you have good fuel and see how it will run either on the hose or in the water. You will probably need to rebuild the carbs if it has sat for long. It sounds like your low speed jets may be clogged. I would not start putting money into the motor until you know it is solid though. If it ran good not to long ago I suspect that a good carb cleaning will make it run good again.

 

[Sandhammaren05]

Re: 1978 Evinrude 140

If the motor's 20-30 years old I'd overhaul it, but then I'm a mechanics. If not that, rebuild carbs, replace fuel lines, and check ignition components. Older power packs were superceded by newer ones, so the old and new ones may look different. You need an OMC service manual for that motor, but you can't check the power packs without special equipment.

I am in the middle of doing a complete restoration of a 1978 Glastron SSV-176. Last night it was time to fire up the engine...for the first time. The engine started...but runs really rough and sputters. It will only idle with lever fully up position. The previous owner replaced one of the power packs..with one for a lot newer engine. I really dont know where to start with this. Whether it might be timing issue or carb...or the power packs.

 

[tmcallister]

Re: 1978 Evinrude 140

Thanks.. I will check these out

 

[kenmyfam]

Re: 1978 Evinrude 140

Compression check and spark test will tell you a lot about the health of the motor. Without doubt a carb rebuild if the other 2 checks are good. New gas and make sure the tank is vented.
Let's go from there.

 

[tmcallister]

Re: 1978 Evinrude 140

I finally took the boat out for it's first test drive tonite. The motor started right up and boat ran really great.. got up on plane and had great power. I continued to drive around at various speeds for a few minutes and noticed power had decreased about 50% during acceleration. Beached the boat and took a short break... and then attempted to start up and head back to the boat ramp... the motor was hard to start... ran very rough... and had very little power. Upon acceleration it seemed like prop was also slipping... engine would rev high and boat speed would not increase. Made it back to the boat ramp... and engine idled just fine while I went to get the truck/trailer.
The motor is currently running one coil that is not the correct model. I am thinking to replace this one first with correct one. Could this be causing the power loss? Also thinking about getting a rebuilt prop. What am I missing here? What should I try next?

 

[crb478]

Re: 1978 Evinrude 140

It sounds like there is more than one thing going on. Check for a spun prop if it seemed to be slipping. What is the compression on the motor? Have you verified good spark? How old is the gas? When were the carbs last cleaned?

 

[kenmyfam]

Re: 1978 Evinrude 140

I finally took the boat out for it's first test drive tonite. The motor started right up and boat ran really great.. got up on plane and had great power. I continued to drive around at various speeds for a few minutes and noticed power had decreased about 50% during acceleration. Beached the boat and took a short break... and then attempted to start up and head back to the boat ramp... the motor was hard to start... ran very rough... and had very little power. Upon acceleration it seemed like prop was also slipping... engine would rev high and boat speed would not increase. Made it back to the boat ramp... and engine idled just fine while I went to get the truck/trailer.
The motor is currently running one coil that is not the correct model. I am thinking to replace this one first with correct one. Could this be causing the power loss? Also thinking about getting a rebuilt prop. What am I missing here? What should I try next?

Start with what I posted 3 posts above back in April but add "check for spun prop" to it.