1990 Force 120HP carbs mix adjustment help

[gica]

Clean plugs maybe is a sign of water intrusion.
Check the head gasket, looks like it is okey from the compression numbers but there are also a chance it will have water intrusion from the exhaust side.
Leakage at the gaskets at the exhaust cover can also cause water intrusion to the cylinders.

Would that cause the dying in gear at normal idle issue?

 

[gica]

Clean plugs maybe is a sign of water intrusion.
Check the head gasket, looks like it is okey from the compression numbers but there are also a chance it will have water intrusion from the exhaust side.
Leakage at the gaskets at the exhaust cover can also cause water intrusion to the cylinders.

Ok took off the cover and I see milky stuff on the 3 and 4 exhaust chambers behinfld the cover. See pics. I need to buy that separation plate as it is too deformed.
Should I remove the head also?

 

[Nordin]

You do not need to buy a new separation cover plate.
It will be deformed too as the heat from the exhaust will make it to warp.
use the one you have.
Check if there is some leakage at the covers or damage.
You need new gaskets and yes pull the head too and check the head gasket.
BTW Another possibility of water intrusion in the bottom cylinder is a bad crank seal at the end of the crank shaft.

 

[gica]

The exhaust plate was pretty warped. I was 0 020in în the worse spots. I used a special stone and brought it at 0.002. I think that even with new gaskets and separation plate it would have still leaked.

 

[gica]

You do not need to buy a new separation cover plate.
It will be deformed too as the heat from the exhaust will make it to warp.
use the one you have.
Check if there is some leakage at the covers or damage.
You need new gaskets and yes pull the head too and check the head gasket.
BTW Another possibility of water intrusion in the bottom cylinder is a bad crank seal at the end of the crank shaft.

I already got the plate for 75 shipped, no biggie. I actually had to re-surface the exhaust cover, it was warped 0.020 which is bad. I used the sharpening stone in the picture and it is now at 0.002. That is acceptable. The crank seal at the bottom was replaced when I rebuilt the damn thing. I had the crankshaft out in pieces. Every seal on this engine is new.
The exhaust cover was way too warped was wondering why every time I torqued the bolts they were loose again in a few days. I will now brush some liquid gasket maker 500C on all the surfaces and use the recommended 750 industrial sealant on the bolts. I truely hope it is the end of the ordeal. I mean there is no part of this motor I haven't touched.
I am just sorry I didn't check the cover and use a straight edge to check the warping. It is weird that the boat was able to ride at all. But the water obviously affected the running at idle in gear. I guess water doesn't light up like gasoline and oil hahaha. I sure hope there is no other reason for the leak as you mentioned. Fingers crossed.

 

[gica]

You do not need to buy a new separation cover plate.
It will be deformed too as the heat from the exhaust will make it to warp.
use the one you have.
Check if there is some leakage at the covers or damage.
You need new gaskets and yes pull the head too and check the head gasket.
BTW Another possibility of water intrusion in the bottom cylinder is a bad crank seal at the end of the crank shaft.

Did you ever change the spark plug wires on a 120hp force. The are built in the coil so only the end of the part that goes onto the spark plug can be messed with?
Any suggestions on where to buy the ends and clips. I assume there is no soldering involved just crimp the new fitting to the wire and slide the boot back right? I am sure mime is corroded so new ends would be really helpfull. Thanks.

 

[Nordin]

As you says you can not change HT wires.
I am in Sweden Europe but here you can buy spark plug boots that you screw in to the wire.
Cut the end of the wire and change boot or clean the OEM boot spring and pierce it in to the wire.

 

[gica]

That's cool Sweden is great, all the compatriots I have that live there always travel. Life must be so laid back.
Anyways, thanks for all your input,
I really do want to change those ends. The screw on ones sound great they might have it here too. I will look onto it.

 

[gica]

So I got all the parts and put the exhaust cover back with the new separstionplate, straight enough cover, and gaskets plus sealant between it all. I even bought new stainless bolts and some washers. I also changed the power head with another one that is a little straighter and no damage inside. Mine was scored a bit from the bad piston in the past. I put it all back and I started it in my home made tank and it runs pretty good in the tank. I had it at 1050rpm. The water jet from the tale I installed seemed more powerful than before. I hope this does something to my issue of dying in gear. Number 4 piston
looks ok after half hour of running. I don't see water on the piston surface like before.
I am including the spark plugs oicture they have some oil on them and a halo light beige in the center.
If this is it and the water issue is solved
Will it fix the dying at idle in gear???

 

[gica]

Hi everyone, I hope you're all healthy and still around.
I have been offshore fishing with my oldie twin 120s Force, today I was testing it because there is a rattle from the shaking that happens only at idle on the starboard motor that has always had problems at idle. I rebuilt the lower drive a second time thinking that could cause the dying in gear at idle issue. I found out that the rattle is from the upper crank ball bearing and the shaking only happens at idle of course. You can also feel it by pulling on the flywheel back and force, it has some play. I did not change it when I rebuilt the damn motor, my bad. The second rebuilt engine is running perfect no rattle noise or issues. If and when I take it apart again, I want to make sure I deal with any future **** that can cause problems especially issues that require complete disassembly.
I have 2 questions can this free play cause the issue where the motor sometimes dies at idle?
Second question to change the bearing do I need to take the crank case apart at the half in other words do I need to disassemble the damn thing again?
Thanks in advance as always.

 

[jerryjerry05]

Yup the DAM thing needs to come apart.
Unless your REALLLLL lucky and the bearing slips off(not likely).
Most cases you'll need a bearing separator.