Johnson Outboard, no idea what is wrong!

[paynes79]

We bought a boat last year on a whim, a 1972 18ft outboard. It has a 100HP Johnson engine.

The first day we took it out it seemed to run fine.

Then the second time(3rd,4th,5th...) it will start up dry(guy at the marina did that one) or if we have the hose connected...but as soon as it goes into the water...it doesn't want to start...or if it does start, it is very short lived.

I have noticed that the back of the boat will occasionally take on some water, and that it even looked like there was gas/oil? in it!

Also when we had the hose connected and started it, the water coming out the hole at the top and the two at the bottom was really hot.

Any clues what could be causing this?
Is it an easy fix, or will it cost us a bunch of money?(we only paid $750 for the boat, trailer, skis...)

Not ready to give up hope just yet!

Any input would be great, we are having a really hard time finding a local service man to help us.

Thanks!
Sarah

 

[paynes79]

Re: Johnson Outboard, no idea what is wrong!

I should say that it does more of a stall out then just an out right not starting.

Also, I remembered that when we were working on it at home(ok just making sure it would start) we had the hose connected but it was spitting out oil too...the proof is all over my white garage door(I blame my husband)

Thanks again!

 

[crxess]

Re: Johnson Outboard, no idea what is wrong!

Ok, one or more of many things could be wrong.
First - how hot is really hot? Scalding hot?

If run Hot it could have blown a head gasket and bad thermostat.
Things to check:
Compression on all cylinders
Spark to all plugs and plug condition. Use a spark tester. verify spark can jump 7/16" gap.
Verify fuel flow. Bulb pumps up tight and doesn't leak down. Pull line at carb and squeeze bulb to check for any blockage.

Spitting out oil is normal on pre-mix motors. it will not use all the mix running on muffs/idling.

 

[krogie]

Re: Johnson Outboard, no idea what is wrong!

your motor is just water shy ( cranks up fine on land and will not run in the water ). there are several reasons this can happen and on is that there is not any backpresure on the motor. hate to sound redundent but compresion, fire , fuel , then i would go to a good carb cleaning and rebuild.