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'94 J40TLERE doesnt sound right

P

ProStreet83C10

New member
Hey guys. My 1994 Johnson 40 hp 2 stroke does not sound right to me at all. Hopefully something simple - also believe it needs a thermostat as engine never gets warm to touch and water exiting engine is BARELY warmer than water temp in run tub.

Will try and unload video of engine running and see what you guys think.

https://youtu.be/yRaOmCM-uDQ
 
Sounds bad.-----Start with a compression test.----Was this a sudden event when it starting running like that.----Oil injection in service ?----Good spark on both leads ?----Flywheel key checked.-----Gearcase oil checked ?
 
racerone said:
Sounds bad.-----

Start with a compression test.- both cylinders known low. 50 and 75.
---Was this a sudden event when it starting running like that. Not sure. Bought boat in off season. Couldnt run it.
----Oil injection in service ? Oil is premixed until i can verify its working.
----Good spark on both leads? Appears to be yes.
----Flywheel key checked. No.
-----Gearcase oil checked ? Changed lower unit oil prior to storing it.
Click to expand...

I also used a stethoscope. Noise coming from around cyl head and water inlet on side of engine. Bottom end quiet.
 
Compression should be 120 + PSI.--------So take the cylinder head off as the next step in your trouble shooting.----It sounds like an EXPENSIVE problem to me.
 
racerone said:
Compression should be 120 + PSI.--------So take the cylinder head off as the next step in your trouble shooting.----It sounds like an EXPENSIVE problem to me.
Click to expand...

Im kinda thinking the same. Not sure what noise would be. Also noticed the engine isnt warming up. After 10 minutes of cold idle the water was still barely above tank temp coming back out of the engine.

Good thing is there is plenty of my era of 40-50hp engine power heads for sale at around 400 bucks shipped.
 
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