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Please, any help would be amazing. 1978 Evinrude 140 - Failed Cylinder

Jmccaig

New member
Hi guys,

I’m hoping there’s someone out there who is able to help a poor bugger with not much engine experience and 2 very disappointed fishing loving boys sitting in the living room right now. I called every mechanic shop and marina within 70km’s of Montreal and none are able to take any new clients pretty much until snow falls.

I've owned the boat for several years now and it has always purred like a kitten. Always winterized and we’ll unkept. Put it in the water on the weekend and it wouldn’t plane as it had no power. After getting turned down everywhere for service, I spent 20 hours reading and watching videos. Here is what I did:

All my explanations are with me standing behind the motor facing the bow.

1- With engine running, unplugged all plug caps. Top 2 and bottom left all wanted to choke engine when unplugged. Bottom right made no change to idle.
2- Verified and swapped all of the plugs (new from last year). All had a bright blue spark. Despite swapping them around, bottom right still was the culprit.
3- Swapped the plug caps and bottom right still the culprit.
4- Borrowed a compression tester and top two read out at 110-115. Bottom left was 115 and bottom right read 25.

So the bottom right cylinder seems to have a problem. I don’t want anyone wasting a ton of time on our problem but I know there’s a heck of a lot of smart people on this forum after reading so much. If there’s any quick trick I am unaware of that may produce a quick fix to this I’d really appreciate it. Summer holidays are here for the boys and we’re stuck on land. Used to fishing several times a week together. Otherwise is there anyone within a few hours of Montreal that has the time and is willing to take on the contract?

I really appreciate any thoughts anyone may have which would allow us to not lose our family activity this summer.

Sincerely,

Jason
 
Hi guys,

I’m hoping there’s someone out there who is able to help a poor bugger with not much engine experience and 2 very disappointed fishing loving boys sitting in the living room right now. I called every mechanic shop and marina within 70km’s of Montreal and none are able to take any new clients pretty much until snow falls.

I've owned the boat for several years now and it has always purred like a kitten. Always winterized and we’ll unkept. Put it in the water on the weekend and it wouldn’t plane as it had no power. After getting turned down everywhere for service, I spent 20 hours reading and watching videos. Here is what I did:

All my explanations are with me standing behind the motor facing the bow.

1- With engine running, unplugged all plug caps. Top 2 and bottom left all wanted to choke engine when unplugged. Bottom right made no change to idle.
2- Verified and swapped all of the plugs (new from last year). All had a bright blue spark. Despite swapping them around, bottom right still was the culprit.
3- Swapped the plug caps and bottom right still the culprit.
4- Borrowed a compression tester and top two read out at 110-115. Bottom left was 115 and bottom right read 25.

So the bottom right cylinder seems to have a problem. I don’t want anyone wasting a ton of time on our problem but I know there’s a heck of a lot of smart people on this forum after reading so much. If there’s any quick trick I am unaware of that may produce a quick fix to this I’d really appreciate it. Summer holidays are here for the boys and we’re stuck on land. Used to fishing several times a week together. Otherwise is there anyone within a few hours of Montreal that has the time and is willing to take on the contract?

I really appreciate any thoughts anyone may have which would allow us to not lose our family activity this summer.

Sincerely,

Jason

You are 99.9% going to find a broken ring. Pull the head off and have a look.
 
Blown head gasket is possible.------Broken piston ring is most likely.----Complete overhaul with 4 new O/S pistons might be in your future.----Shocking amount of money if you have to pay a shop.-----Then you also need to pay attention to inspecting the gears , resealing gearcase and new water pump impeller.
 
You are 99.9% going to find a broken ring. Pull the head off and have a look.


Thank you so much for the response. You’re awesome.

So when you say head, I’m assuming you are referring to only the face plate held on by 14 bolts?

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