Look at this engine

[magialatina]

I'm a totally newbie. I have a Johnson 85 hp 1976 gift. You can hear the sound of the engine, any sugestion where to start [/B]to rebuilt or what is wrong with it. I changed the spark plugs, I'm thinking to replace all 4 coils, Tune-up and seafoam the pistons and new 2 carbs kit. The compression is: 115, 120, 90, 105.

Look and hear the engine here:
http://eduardosphotography.com/Galleries/Boating/myBoat/videos.html

(there's 2 - 30 sec. movies, click the icons at the bottom of the movie)
pls help...

 

[jay_merrill]

Re: Look at this engine

Decarb the motor and do another compression test. Hopefully, the numbers will get a little more even. The 30 psi difference between he lowest and highest cylinder is pretty well beyond the usually accepted norm of 10 - 15% differential.



???

 

[5150abf]

Re: Look at this engine

Agree, if you can't get the compression up in that one cylinder you are certianly looking at a rebuild.

From the video it sounds like you have at least 1 dead cylinder too, there is a pretty regular dead thump.

I would start with a good decarb before I dropped any money into it, you can replace alot of parts and still not correct the compression problem.

If it doesn't come up you need to think about whether you want to drop that kind of money into it to od a rebuild.

 

[F_R]

Re: Look at this engine

There are two schools of thought on that. One school says you have nothing to lose by trying the conservative method (de-carb). The other school says yes you do have something to lose. If it has a busted ring or something, it will get worse very rapidly if you continue to run it, and you may wind up with total junk.

Choose your own school.

BUT if you choose #1 at least first inspect the motor by removing the cylinder head and intake & exhaust covers to see what is causing the compression loss. If you find damage don't run it any more.

 

[ezeke]

Re: Look at this engine

Agree with F_R. Plus, you may just have a bad cylinder head gasket.

 

[tashasdaddy]

Re: Look at this engine

good advice, i could not get any audio.

 

[ezeke]

Re: Look at this engine

BTW, you might want to check the seal between the inner exhaust housing and the gearcase (part #0314937).

 

[magialatina]

Re: Look at this engine

Thanks for all your help, I'll keep you posted after I decarb the engine this week. If u know about any "cheap" working engine +- 100 hp, let me know, I'm in CT. thanks

 

[boobie]

Re: Look at this engine

My ears are probably going bad but if the audio is correct I picked up an ignition miss in the mtr. Also a lean sneeze.

 

[magialatina]

Re: Look at this engine

This is a 85esl73, I thought it was 76.
My engine compression are: 115, 90, 120, 118.
I'm thinking to repair the piston #2 (my bottom left). When I inspected this engine, (a gift), I noticed rusted screws head at the bottom of the Exhaust outer cover and many other places. I tried to take out the cylinder head cover and 2 screws broke inside. This boat/engine was "abandoned" on salt water for 7 years. My question is: How can I remove these rusted screws from the engine?
pls help

I have another question on the back of my head.... it is worth it?
or maybe it could be a learning experience...
(I have worked with car engines but not with boat engines..)

pics:
http://eduardosphotography.com/Galleries/Boating/Pics/RustyScrews.html

video:
http://eduardosphotography.com/Galleries/Boating/myBoat/videos.html
See pictures and video...
ed

 

[HighTrim]

Re: Look at this engine

I have had luck with a good dousing of lubricant and a left hand drill bit. Im not a real big fan of EZ Outs.

 

[steelespike]

Re: Look at this engine

I have no personal experience with salt water motors only anicdotal:
The salt makes them nearly impossible to get apart,internal corrosion
can cause total distruction creating stories of even with careful flushing and
preperation corrosion leads to throwing away motors.
I think its pretty obvious your unlikely to get inside without extreme patience
and some luck.I'm sure those with experience may be able to help or be more specific.