1973 Johnson 85 HP Compression and other questions

[joshua27]

I recently acquired a 73 Johnson 85 HP motor on a pontoon boat I picked up. The motor currently will not start. I changed the starter due to the motor turning over slowly and now I think the solenoid is bad because I can't hear it click when I turn the key. I "jumped" the starter out with some jumper cables and cranked the motor over to check compression. The readings are:

1: 123 psi
2: 120 psi
3: 115 psi
4: 111 psi

Are these readings okay considering the motor is not warmed up and it's 40 degrees outside?

Also the motor is not getting any spark, it appears that both of the coils on the stator have melted down as I can see evidence of the goo inside them from under the flywheel. Would this cause the motor to produce no spark at all or is their something else I should look for?

I'm also curious if the motor is even worth dumping money into to get going as it appears it might be a basket case. If I end up having to buy a new stator, coils, powerpack, etc. the cost could add up very quickly.

 

[F_R]

I see several problems.
1. Turning over slowly. It has to be cranking 200 RPM or more to produce a spark.
2. Coils leaking goo. That was a big problem with the 1973 model year. Are you sure it isn't goo from coil leakage sometime in the past? Whatever, it certainly willl cause a no spark condition if the present ones are leaking, especially when combined with slow cranking
4. #4 cylinder is a bit low, but probably not an issue concerning the current no-start problem. Might be some ring stickage.
5. Stop thinking about replacing the power pack unless it is proven to be bad.

 

[emdsapmgr]

A fresh engine from that vintage will have compression in the 125 range. We always figure that if the spread is within 10% between all cyls- that it's ok to run. I'd be inclined to run some Bombardier Engine Tuner through the engine in an attempt to clean out some of the carbon buildup around the piston rings. Esp concerning pistons 3 and 4. One or two applications and you may find the compression will some up somewhat. Maybe not a lot, but you will find the engine will live longer and idle better if the carbon is cleaned off the ringsets and piston skirts. You will find some excellent ignition troubleshooting info in the ignition guide at this website: cdielectronics.com

 

[oldboat1]

think I would pull the plugs for cranking, if you haven't done that. Test the spark with a spark tester while the plugs are out, and try the tuner treatment. Retest compression. Sounds like room for some basic troubleshooting on the starter circuit.

 

[joshua27]

Thanks for all the replies guys. Very helpful. I'm also stumped on something else. Currently the outboard has the wrong stator which I'm assuming is why it melted down. It has a stator from a 3 cyl outboard. The v4s came with a 6 or 12 amp stator, how do I tell which one my boat needs?

 

[racerone]

Some of these look the same , but are not.----Get a 4 cylinder stator first of all.

 

[emdsapmgr]

There was only one stator option for the 85 hp model that year, the 6 amp alternator. In later years an engine that had power trim used a 6/9 amp stator. But in your year, the 581046 stator was the only one called out for all V4 powerheads. Bombardier has superceded that part to the current part number 763772. The factory has a couple new ones in stock.