93? 150hp Johnson fail to run

[Mowens]

So I have this motor and after a lot of tinkering on the boat I attempted to start it.

Turns over wouldn't start. Sprayed some fuel in the carb throat and it sputtered wouldn't run. Put on small portable tank with fresh fuel and fuel line to engine. No change.

About this time I looked at the spark plugs and saw some milky white "water" assuming bad head gasket.

I did a compression test and got

100 - 90
90 - 90
100 - 95

Spec should be 100 so im not completely out of range.

Not sure the next step

 

[racerone]

On a 60 degree looper model there is an o-ring.----No traditional head gasket.----Model # is ??

 

[Mowens]

On a 60 degree looper model there is an o-ring.----No traditional head gasket.----Model # is ??

That's part of the problem. The powerhead was replaced at some point. The model number on the bracket is for a sea drive omc. I can find only a freeze plug but that number doesn't seem to correlate to anything.

 

[racerone]

That picture is no help at all.-----Post some pictures of the powerhead !!----I do not believe it is a 93 model at all !

 

[Mowens]

That picture is no help at all.-----Post some pictures of the powerhead !!----I do not believe it is a 93 model at all !

 

[racerone]

1990 is listed as the last production year for SEADRIVES.-----So you have a crossflow engine.----Those compression numbers are not encouraging.----Might be a blown head gasket.----Or broken rings as was common on those.----Water inside a 2 stroke is DEATH to bearings.------Myself I would be taking this engine apart for inspection !

 

[Mowens]

[No message]

 

[racerone]

Well that is a 60 degree looper style engine.-----Post pictures of the Seadrive set-up.

 

[Mowens]

Well that is a 60 degree looper style engine.-----Post pictures of the Seadrive set-up.

Thanks!

I'll get pics shortly of the seadrive

 

[Mowens]

[No message]

 

[racerone]

Interesting.----I do not believe that is a factory built unit.----Someone put this together.-----Do you have spark on all leads ?------Cleaned the carburetors ?----Are you pushing the key in while cranking it over ?------Do you know how to use the red lever on the electric primer ??----I do see a boat / motor shopping trip in your future.

 

[Mowens]

Right someone replaced the power head. I do have spark I replaced the coil packs. I cleaned and reassembled the carbs. Yes pushing key in. Can hear the choke when I do and yes tried manually

My assumption of 1993 model was based on carb parts and the manifold gasket.

I'll pull the covers tomorrow and check piston and get new gaskets coming.

Also seems to have a fuel leak on the manifold at the second carb. I'll pull that as well abd replace the o ring.

Maybe that will get somewhere.

 

[Mowens]

So I got the port side off. The o-rings weren't there. Someone had used rtv sealent to make a gasket. I didn't see or feel any damage on the piston walls.

Ran out if light. But I'm guessing new o-rings to start.

Curious thing. I wanted to retest spark. So I was getting no spark at the plug i moved the tester to the coil end and ran a line to ground and it lights up. Using my light at the coil end I'm getting spark and it looks like blue and jumps pretty far.
But using my light I couldn't get anything out of the spark plug wires. I replaced them 2 years ago when I bought the boat. Could they have gone bad? Mind I didn't test every wire like that just the top 2.

 

[oldboat1]

Test all wires individually for continuity, boot to boot.

 

[Mowens]

Test all wires individually for continuity, boot to boot.

Thanks Will do that in the am. Also get the stbd side off.

 

[Mowens]

Ok starboard side off.

Looks like the o-rings on this side a little better shape then on the port side they where in pieces held together with rtv.

Turned the flywheel everyhing looks good. No sign of damage inside.

All the little holes in the head are filled with rtv I'm assuming I need to clean that out. Is there a way to flush that with the covers off?

In the manual it doesn't mention using any but should I use any sealant anywhere when reassembling?

So last thing I noticed is black in the cups on the covers in only 3 and 5 all the rest looked new. I am guessing I was only getting combustion there. But I'm not sure if that was prior to me repalcing the coils.

Still need to test spark wires.

Getting there so slowly.

 

[racerone]

Does spark jump a gap of 7/16" on each lead , yes or no ?----

 

[Mowens]

Does spark jump a gap of 7/16" on each lead , yes or no ?----

So if I check at coil side yes. If I check at plug side nothing. Like the wires are bad. Need to pull them check continuity.

I assume they are going to the correct coil they are zip tied down in place

 

[Mowens]

Ok plug wires either read as 1 ie open on continuity or 17xx on the multimeter.

Coils all read right at 290 on each side.

 

[racerone]

Are the plug wires a metal core wire or something else ?----If you are not getting spark that will jump a gap of 7/16" at the plug boot, there is something wrong !!