1980 85 hp evinrude starting problems

[neilly boy]

I have 1980 85 hp V4 evinrude. will not start unless its primed by spraying fuel into the cylinders. Once it starts it seems to run ok. It simply will not start unless its primed. Carbs are good, I took them apart and cleaned them thoroughly. new gaskets etc. electric choke is working . Fuel pump seems to work ok. Carb bowls were full when I opened them . Fresh gas . and good spark. I did a cold compression test that showed all cylinders were hitting around 90. Starts right up with priming. though it seems to run a bit rough at low idle. I looked at cylinders with an endoscope . there is some scoring evident on cylinder walls.

 

[racerone]

Are you pushing the key in while cranking it over ?----Are you advancing throttle while cranking ?-----And load test your battery.----Inspect starter brushes.

 

[neilly boy]

Are you pushing the key in while cranking it over ?----Are you advancing throttle while cranking ?-----And load test your battery.----Inspect starter brushes.

Yes I do push key in. and advance throttle. Tried numerous throttle positions. It cranks over ok.

 

[racerone]

So with the 4 sparkplugs left in , does the spark jump a gap of 3/8" ( 1 cm ) on a testing device.----I would like to see compression of 120 PSI on those.----But perhaps remove the bypass covers on the cylinders that is showing some scoring.----The trouble shooting has to be done by you.

 

[ahicks]

My bet is your choke (or "enrichening device") isn't working. That would be where I would start....

 

[neilly boy]

My bet is your choke (or "enrichening device") isn't working. That would be where I would start....

its an electric choke and it is working. I hear the click and can see the butterfly close. thanx

 

[neilly boy]

So with the 4 sparkplugs left in , does the spark jump a gap of 3/8" ( 1 cm ) on a testing device.----I would like to see compression of 120 PSI on those.----But perhaps remove the bypass covers on the cylinders that is showing some scoring.----The trouble shooting has to be done by you.

ok will check it out thanx

 

[ahicks]

its an electric choke and it is working. I hear the click and can see the butterfly close. thanx

Is the choke closing completely, or is there a chance it may only be closing partially?

Is it running OK once started, with a smooth idle?

 

[neilly boy]

Is the choke closing completely, or is there a chance it may only be closing partially?

Is it running OK once started, with a smooth idle?

I think the choke is closing completely. there is a small gap at the bottom of the butterfly but I think its good. It runs pretty good once it starts but is a bit rough at idle.

 

[racerone]

What is the model # of your 1980 ?--85 HP.----I thought those had the electric primer.----If in fact yours does have choke flappers then adjusting the solenoid might help.

 

[neilly boy]

So with the 4 sparkplugs left in , does the spark jump a gap of 3/8" ( 1 cm ) on a testing device.----I would like to see compression of 120 PSI on those.----But perhaps remove the bypass covers on the cylinders that is showing some scoring.----The trouble shooting has to be done by you.

What is the model # of your 1980 ?--85 HP.----I thought those had the electric primer.----If in fact yours does have choke flappers then adjusting the solenoid might help.

e85stlcsa. It definitely has choke flappers. and no it does not have electric primer. I will take a look at the solenoid adjustment

 

[ahicks]

Racerone and I are on the same page here. The choke, to be most effective, needs to be closed completley to work properly/be most effective.

One other thought, is a chipped or broken reed valve can cause these kind of headache as well. They need to seal in order to cause the kind of suction required to get the motor started. After that, they need to seal for a good idle. Once rpm's rise above idle, a small reed valve issue isn't nearly as noticeable.

That said, the valves DON'T need to be completely closed when idle. The pistons will blow them closed if open slightly. It's when they are actually broken or chipped that you have an issue.

 

[neilly boy]

Racerone and I are on the same page here. The choke, to be most effective, needs to be closed completley to work properly/be most effective.

One other thought, is a chipped or broken reed valve can cause these kind of headache as well. They need to seal in order to cause the kind of suction required to get the motor started. After that, they need to seal for a good idle. Once rpm's rise above idle, a small reed valve issue isn't nearly as noticeable.

That said, the valves DON'T need to be completely closed when idle. The pistons will blow them closed if open slightly. It's when they are actually broken or chipped that you have an issue.

thanks for your input. I adjusted the choke solenoid to close the flappers completely. I started it and it ran but very rough idle then stalled when I tried to idle it down. I will have to check the reeds. Something I suspected from the get go. FYI I bought this boat recently for a cheaper than cheaper price. Again thanx

 

[racerone]

Some will argue.----Remove bypass covers for inspection of pistons and rings.----No point wasting time and effort if motor needs rebuilding.

 

[ahicks]

Some will argue.----Remove bypass covers for inspection of pistons and rings.----No point wasting time and effort if motor needs rebuilding.

Going through the carbs may not be a bad plan either....

 

[neilly boy]

Going through the carbs may not be a bad plan either....

I took the carbs apart. They were very clean The only blockage was in the small jets at the base. they were thoroughly cleaned and looking good now. but it made no difference in startup.

 

[neilly boy]

Some will argue.----Remove bypass covers for inspection of pistons and rings.----No point wasting time and effort if motor needs rebuilding.

i removed the cover. can't see a lot. but the pistons don't look too bad. i will get a closer look tomorrow. What indicates a rebuild is needed.?

 

[oldboat1]

If it's a primer system, as based on the model number, hold the key in while cranking. Once it starts, you may have to bump the key in to keep it running while it warms up. The red lever should be parallel to the primer body for normal starting and running. (may be time to rebuild the primer).

If there is a choke flapper (front of carb throat, with throttle flap in the rear), physically make sure it is closing tightly in the full choke position for starting. Use your finger to make sure it is sealing shut. Also a good idea to try the manual choke system if auto choke issues.

 

[neilly boy]

If it's a primer system, as based on the model number, hold the key in while cranking. Once it starts, you may have to bump the key in to keep it running while it warms up. The red lever should be parallel to the primer body for normal starting and running. (may be time to rebuild the primer).

If there is a choke flapper (front of carb throat, with throttle flap in the rear), physically make sure it is closing tightly in the full choke position for starting. Use your finger to make sure it is sealing shut. Also a good idea to try the manual choke system if auto choke issues.

it is not a primer system. Its a flapper. I adjusted the choke solenoid so the flapper is shut tightly.It works and closes when the key is depressed. Still doesn't want to start unless its primed with a squirt of fuel down the throat of the carb with the throttle wide open. Then it starts at high revs and will keep running until the throttle is backed off to idle., then starts getting rough and conks out .

 

[racerone]

Need to address the scored cylinders that you observed / reported.-----Perhaps power head or carburetors have been replaced on this motor.