1990 Force 90hp NO compression cylinder 3

[Mackus84]

Well, finally got the head off to take a look. Definately ate a ring or something! Bore actually looks great, the piston on the other hand........

 

[Mackus84]

Just to clear it up, being a C-model, is this all that I need? When I put in my part numbers this comes uo as my replacement part. Seems super cheap. Just wanna make sure before i buy it.
https://www.offshoremarineparts.com/11-11-205.html

 

[jerryjerry05]

The off brand pistons aren't that costly.
Wiseco is what I usually buy, more expensive but worth the $ because I know I'm getting the right stuff.

You'll need a bearing set for the wrist pin.

You going to do the work yourself?
Some people remove the intake and replace the piston without removing the block from the mid-section.

I prefer taking it all apart and replacing the rings in all the pistons.

Remove the piston and measure it before you buy anything.

I'm over in Sebastian.

What ever you do.
DON'T remove the exhaust chest.
When you get the piston out you can inspect the exhaust and see if it needs new gaskets.
Usually they don't go bad unless you repeatedly overheat.

 

[Mackus84]

I'd prefer Wiseco as well. Thats who I use on my Atv/ATC's that I rebuild. But from what I saw they only have the "A" model pistons. 3.31

 

[Mackus84]

Also, the head has some "ding" marks in it similar to the piston. Not nearly as bad, but you can see them. Is it usable? Theyre plentiful and cheap on ebay so if I need to replace it, its no big deal

 

[Nordin]

Mackus84 ....Wiseco piston for your engine if 3,375 in bore is
3151PS standard bore size
3151P1 010 oversize
3151P2 020 oversize
3151P3 030 oversize
3151P4 040 oversize

BUT they are alot more expensive then your offshoremarine link.
They start at 122.00 dollar at Wiseco.

I also prefer Wiseco, but I maybe will try WSM or PRO-V because of better price.

What brand is your offshore link?


Have you checked outboardpartsdotcom?

They have Wiseco for 107.00 dollars.

Mastertechmarine has PRO-V or WSM about 88.00 dollars.

 

[Mackus84]

Im gonna get the piston out first. I have the carbs, manifold and reeds out, and have the 12 point 1/4" conrod bolts loosened, but trying to figure out the best way to make sure all the rollers dont fall out before i fully remove anything... also, the pistons all have a big B stamped on the top if that means anything

 

[Mackus84]

Ok, got everything safely apart through the reed opening. Not hard at all. Little nerve racking with the big end rollers but thats it. Piston is DESTROYED, only about 2/3 of the bottom ring left, too ring completely gone. Somehow by the grace of god, the bore looks absolutely fine. Not a scratch on it. A little worried about the missing pieces of ring though. Anyways, gonna get the parts ordered and get this baby back on the water. Cant wait!!

 

[jerryjerry05]

The dings in the head? They shouldn't be a problem.

The pieces probably went out the exhaust.

The roller bearings need "assembly grease" when you put them back in.
Regular grease won't melt as fast and can cause scorched bearings and crank.

Make sure you count the bearings.
If my memory's right??? 16

 

[Mackus84]

Yes, there is 16. All accounted for

 

[Mackus84]

Finally! After some broken head studs, and some frustrarion, she is back together and running great. Just gotta get her in the water to set the idle and we are ready to roll!!

 

[Mackus84]

Also, if anybody could tell me how to wire up this 20 pole Faria Tach, that would be great!

 

[kbh121956]

Markus84, Glad that you got her running! The purple wire is your signal terminal on your tach. Black is your ground. The battery you can hook to your I terminal on your key switch, that is the small light for night viewing. Make sure that you have your new tach switched on "20 pole" if the engine was a 20 pole. Happy boating!

 

[Mackus84]

Ok cool. Now this 1990 Capri did not have a factory tach. So do you think i will still have the purple wire under the dash or will i have to run one to the motor?

 

[jerryjerry05]

The harness from the motor should have the purple wire taped back somewhere under the dash or in the shifter??

But be careful as the purple lead isn't always the tach lead.
It's also used as a power lead to the instrument panel .on some applications.

If you find it? Check it for voltage. 12v?? not the tach lead.

 

[Mackus84]

Cant find any taped back wires, but ill also admit im hesitant to start tearing into factory wiring as this boat is virtually untouched and wiring isnt my specialty. Only purple wire I found was hooked to what looked like my overheat buzzer maybe?

 

[Mackus84]

Ok i take that back. I pulled the panel with the ignition switch, and there is a purple wire taped back, it had an extension on it that didnt match thats why i didnt see it. Gonna test for voltage. Is there a ground on the ignition switch?

 

[jerryjerry05]

The overheat can have a purple lead maybe an orange lead??
The orange should lead to the thermo switch on the head.

 

[Mackus84]

Ive got the Tach hooked up and working. Took the boat out yesterday, ran beautifully!! Got the idle set to around 750/800 rpm. Did some varying speed passes on the water followed by a cool down period. Re-torqued the head . Everything went great. Running a 15p prop, i got about 5300 rpm at WOT @ 36mph on my gps app on my phone... Got up on plane quickly and easily.... very happy overall. Had a new issue come up tho, the speedo was previously no working, but yesterday it was actually filling up with water! And leaking from under the panel as well. The faster i went, the more it leaked. Im assuming the speedo is probably toast. Can i use an aftermarket speedo or do i need to find the direct replacement?

 

[jerryjerry05]

What kind/size of boat is this on?
Heavy load? lots of people?

A 15p is usually for bigger boats or some pontoons

Yup the speedo's done.
Any speedo will fit in the hole and work.
The holes are a standard size on most boats.