1990 Force 120HP #2 Cyl zero compression and upon opening piston shows damage

[gica]

So I was on another thread and was asking about timing one person told me I might have engine issue to which I said no way. Well it turns out he was right this is a dual 120HP 2302 Trophy. Haven't taken it out since last year and I had the 2500 RMP discovered the plate was not adjusted right and the timing adjusting screw did not have a securing nut. So if anything happened it didn't happen on water it happened while I was messing with the screws to get the idle down. The boat was driving nice the last time.
So I will include pictures of the damage. if I trace on the cylinder wall I don't feel any damage but there are marks if you just look. I will clean it with some thinner tomorrow see if they are permanent and also measure the cylinder wall as far as I can with the piston in.
The marks you see on the wall of picture 3 are not palpable by touch. Of course that won't mean much

I basically want some guidance of the easiest way to approach this don't want to throw the engines away yet. I have the tools and the know how. Just never worked on a Force engine. Have done other 2 strokes but Yamaha JetSkis.

 

[jerryjerry05]

From my experience an outboard's just an outboard.
If you can rebuild one then the job won't be so bad.
Dismantle and do an inspection. Any doubt then replace the part.
New pistons and rings. Wiseco is my choice.
Good luck, keep us posted.

 

[gica]

Thanks.
Once I measure the #2 cylinder after cleaning it I can see if it needs to be bored. I can probably hone it. Any idea what size pistons these have I see .010 all the way to .040 but what is stock? This piston just started to get damaged.

 

[ErSa]

General question: I have seen so many "scratched" cylinders in this Chrysler forum! Do anyone have an idea what causes the scratches and how can we avoid them or it is a natural way for a Chrysler outbordmotor to die?

 

[racerone]

Lack of maintenance.----Many folks do not realize that most outboards require a new impeller about every 5 years.------Quality of the oil.-----Wrong pitch prop for the size of boat and load.-----Sorry , most folks think that if a motor starts , barks and roars that nothing can be wrong.

 

[gica]

Lack of maintenance.----Many folks do not realize that most outboards require a new impeller about every 5 years.------Quality of the oil.-----Wrong pitch prop for the size of boat and load.-----Sorry , most folks think that if a motor starts , barks and roars that nothing can be wrong.

I agree this boat is new to me and I did not check it properly when I got it, my bad, but I am in the habit of fixing everything I get. I already changed the dash gauges and actually resurfaced the whole area. he fishing season started. I was doing other things like a trailblazer rebuild, 12 BMW 328i full rebuild, my son literally charred the motor when he ran out of water and drove another 25 miles even with stops every 5. I rebuild a Yamaha 1200 jetski completely. Did not even take it out more than 3 times. It's a curse.
I am a little pissed that I didn't do this motor before the fishing season. Now I have to rush and am not sure if the parts are readily available.
I am going to measure and clean and start taking this thing apart.

 

[racerone]

A wise man would also look at the cylinders on the other motor.-----Order an extra head gasket is all it would take.----Don't forget new impellers and seal kits for the gearcases too !!

 

[racerone]

Be a shame to fix one motor and have the other one go phoofff a month later.-----Was involved in commissioning a 28' antique runabout.--Owner had just bought it.-----One of the Chrysler flathead 6 engines was bad.----We suggested why not do the other motor too.-----He did not argue , said --" brilliant send them both for rebuilding "-----Was in a position were money was not a problem I think.

 

[Nordin]

I agree with racerone, maintenance is prio 1.
Good two stroke oil, change LU oil every season, run the carbs out of fuel in the autumn and run it in fresh water.
Remember that these old engines are ........yes old.
Do not run the hell out of it and they will last for a very long time.
#ErSa, scratched cylinder walls are not common only for Chryslers.
Does not matter if it is a Merc, OMC , Yamaha, Suzuki or Chrysler, I have seen it at all brands.

 

[gica]

A wise man would also look at the cylinders on the other motor.-----Order an extra head gasket is all it would take.----Don't forget new impellers and seal kits for the gearcases too !!

opened it at the same time

 

[gica]

Ok I am stuck at the connecting rod bolt. What the heck size is that? Is it a 12 point
or special size? It's smaller than a 7 and bigger than a 1/4

 

[The Force power]

Ok I am stuck at the connecting rod bolt. What the heck size is that? Is it a 12 point
or special size? It's smaller than a 7 and bigger than a 1/4

6 mm 12point, a wrench will remove the bolts but.......
You'll need a socket (1/4 drive) for re-assembly torque

 

[gica]

Thanks

 

[The Force power]

Thanks

Be care full ! don't loose any of the needle bearing DON'T USE a magnet!!

 

[Nordin]

You need a 12 point 1/4 socket with thin walls.
I recommend you to buy a quality socket from Facom, Snap on, Bacho or other brands that they use at workshops.
When reassemble it you have to torque the connecting bolts to spec value and that will require quality tools.

 

[gica]

You don't think Gearwrench will cut it?

 

[The Force power]

You need a 12 point 1/4 socket with thin walls.

Yes!! I had it wrong (too many tools in my box)

 

[The Force power]

You don't think Gearwrench will cut it?

For removal; Yes
For re-assembly; No

 

[jerryjerry05]

1/4 12point Craftsman makes that socket.

 

[The Force power]

1/4 12point Craftsman makes that socket.

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