Johnson gasket replacement

[nyrick]

I am looking to possibly buy a mid 80's Johnson 100HP. (I think) Owner says it runs strong w good compression but it needs a gasket replaced between the power head and the lower unit. This was told to her by a marine mechanic. She knows nothing more. I am not a mechanic and am wondering if anyone knows how big a job is this and what is a realistic price I am going to pay to have it done. OR should I walk away from a 30 year old engine. Boat is in north Jersey if anyone wants the job to repair. Thanks

 

[racerone]

Post model # or picture of this motor.

 

[Vic.S]

I am looking to possibly buy a mid 80's Johnson 100HP. (I think) Owner says it runs strong w good compression but it needs a gasket replaced between the power head and the lower unit. This was told to her by a marine mechanic. She knows nothing more. I am not a mechanic and am wondering if anyone knows how big a job is this and what is a realistic price I am going to pay to have it done. OR should I walk away from a 30 year old engine. Boat is in north Jersey if anyone wants the job to repair. Thanks

Part #37 in the diagram below presumably.

Same gasket used in a wide range of engine hps and years

Obviously the power head has to come off to change it

 

[nyrick]

Thanks Vic. I assume I am looking at everything under the power head in that diagram. Do you have a ball park idea what that would cost to have replaced. Anything else that should be done while the mechanic is in there. Thx in advance.

 

[racerone]

Thermostats and poppit valves..----On a fresh water motor the job would take about 2 to 3 hrs.----Salt water motor it can get much more involved.

 

[emdsapmgr]

A common failure on the crossflows. Just a messy problem, but not any indication of future catstrophic failure. Bombardier flat rate for a powerhead R&R is 3.0 hours. Other than lifting the powerhead up to clean the gasket surfaces, it just normal labor. The gasket is about $ 24.00. The factory makes two different base gaskets. A plain paper one, and an upgraded one, with paper sandwiched between two aluminum sheets. You'll want the upgraded one, or you'll be changing the cheap one out in the near future.

 

[nyrick]

Thanks a lot. I am handy and don't mind trying to replace this myself. Does anyone know what That particular gasket as pointed out in the above diagram is called and if there are any tutorial videos on removing the power head and replacing the gasket etc? Does not look all that complicated. Thanks

 

[Vic.S]

In the BRP parts list ( which is where the diagram comes from It' called "Gasket, adaptor to power head"

The packaging may however be labelled " GASKET, Plate to cylinder and crankcase"

It is listed as part number 0321727 but i do not know which of the alternatives mentioned above that is. That appears to have been superseded by 0342513

 

[racerone]

Make sure you get the latest revision as the gasket is much improved with metal core !!