1990 Force 90Hp Over heated

[scudrunner]

I have recently purchased a 1990 Force 90 (906x90a) from a close friend who had some problems on the last trip out. Hence, the transfer of ownership! Basically I need to know how to approach this motor. The motor seems to be in fairly good condition (no corrosion or beat parts) It has been stored most of it's life and has went long periods of time between runnings (2-4 years). This spring he had a new power pack installed and has ran the boat approx. 6 times this year. The last trip out, it had overheated and quit running. I believe he shut it off when the overheating alarm went off. He tried several times to restart the motor with no success. He had to be towed in. 48 hours later it is sitting in my drive way. After lifting the hood, I see that it was marked that it was rebuilt in 11/1993 and bored .030 over. I purchased the boat knowing that the motor may be junk, but if I can resurrect this motor, I would sure love to. I have some mechanical experience, though not on outboards. I feel that I am semi-handy with a wrench and would like to try to repair this myself. (And I have very limited funds). I admit that I am somewhat intimidated, but with a little help, I may be able. I wonder if someone could give me a plan of what to look at first, second.....etc. Any help would be greatly appreciated. I have been reading various posts and I am impressed with the level of skill all of you seem to possess. Thanks in advance!!!

 

[wayne h]

Re: 1990 Force 90Hp Over heated

first thing is a compression test of course after you get a manual that will walk u though everything u need to know

 

[scudrunner]

Re: 1990 Force 90Hp Over heated

Does anyone have a manual for sale or a good source for a factory manual? How far should one go into repairs before drawing the line in the sand? Subjective, I know, but.........Thanks

 

[wayne h]

Re: 1990 Force 90Hp Over heated

good place for manuals is here or ebay .. as far as where to draw the line will be up to you and your skills but first you need to check compression and go from there

 

[scudrunner]

Re: 1990 Force 90Hp Over heated

OK, tried checking compression......it cranked a few times, like 5 or 6 times and then locked up solid. Couldn't bump it with the starter or with a rope in the slot on top of the flywheel. I guess any minor type solutions may be out of the question? Any suggestions? Thanks!

 

[wayne h]

Re: 1990 Force 90Hp Over heated

u cant turn the fly wheel either way by hand ? both plugs out ? its hard to say without being there but its the same steps as any other engine look at the basics first and go from there .. pull the head and look at the cylinders .. find out why its locked up .rust in the cylinders , broken rod , there are lots of things it can be . from here you have nothing to lose .. u might learn a thing or 2 in the proses .not to sound like a jerk but from what u are writing in i think that your skill level might be minimal. i would not have winged the motor over without lubing the cylinders first and checking it by hand before i hit the key . if all else fails u can always sell the parts on ebay or local and make a few buxs for your new engine ..

 

[scudrunner]

Re: 1990 Force 90Hp Over heated

You are absolutely right, I have minimal experience with outboards. Of course, I have talked to everyone I know about this senario, but I am a little light in the practical experience catagory. I think I will do exactly what you suggested....systematically tear into it and if nothing else, I may learn a thing or two. Thanks, I will post more as I discover more.

 

[wayne h]

Re: 1990 Force 90Hp Over heated

tear into it with the mind set that you are gonna find out whats wrong and fix it .. let us know what u do find . most of the time over heating a force engine is not good BUT i would really like to see what u discover .. do a search for your engine you might find some more ideas on what to look for and where to start tearing into it .. but i think that the head is a good safe place to start .. but before that i would spray up the cylinders with some good penetrating oil and let it sit for a day or so .. work the engine by hand back and forth from the fly wheel and see what happends .. it might have rusted cylinders. again its a good teaching aid and is worth more in parts if u cant fix it then it is as a whole .. the lower units fetch pretty good money .. i have bought engines whole for less then what the lower units sell for when taken off .. SO if all else fails u learn alot and have a pile of parts to sell ..

 

[Frank Acampora]

Re: 1990 Force 90Hp Over heated

That is a three cylinder engine. As long as it has not thrown a rod and scored the crankpins, a complete rebuild with three oversized pistons (assuming you do all the work except boring the cylinders) will cost around 700 bucks. Used engines sell for that, but if you enjoy it, rebuilding can be very satisfying--and, you know exactly what you have as opposed to an unknown used engine. So: tear into it and see exactly what is wrong and take it from there.

And, if you do end up doing a complete rebuild, while you have the block apart and before you bore it, why not do some port work and gain a few more horsepower? It's easy and only takes about an hour per cylinder with a Dremel and a carbide bit.

 

[scudrunner]

Re: 1990 Force 90Hp Over heated

Thanks for the advice, I am actually looking forward to tearing apart this motor and gaining the knowlege from this. I have always been intrigued with outboards and now I believe it's time to find out why. What's the worst that can happen......have some parts to sell on ebay? Sounds kinda like a win win proposition! I plan to start this weekend, so I will let you guys know soon.