50hp blown head gasket/wrist pin

Hello members. So I buy this boat, motor and trailer knowing there was a issue with the motor. A very clean looking 1989 Force 50 hp. The price didn't include any cost for the motor. The previous owner said he was told the something about a piston pin. I didn't care or even look at the motor per say. Even if it ran perfect I wouldn't want it due to 25 hp restricted lake. I get it home and pull the cowl. The head was attached by one bolt. I pull it and see two things. I tried posting pics but can't figure it out because I can't put a wrench on it. First thing that caught my eye was the bottom piston and head chamber were clean. Espically in one specific area. My thought was a blown head gasket. Then I see two perfect gouges on the very bottom of the cylinder. Right between the two ports. Possibly matching his explantion of the piston pin . So then I emailed him some questions. He said the motor started running rough with no power. Dosen't remember any noise. I think there may have been a issue going on with the piston pin he didn't know about. Then the head gasket blows. He takes it in and is told about the piston pin. Question! What would cause the pin to drop and cut into the cylinder. Unless it was made that way. The motor turns over by hand fine and feels fine on the strokes. I ordered a new gasket to put it back togeather and see what happens.

The original piston and wrist pin were pressed in.
I'd never seen one loosen enough to slide back and forth.

IF???? the piston was changed somewhere along the line, they could have used an aftermarket piston and pin.
Most all aftermarkets use a floating pin and spring pin locks.
Possible the locks weren't installed right or bent when installed and they fell out?????
Or????? the pin and bushings failed??

Check the top of the piston for ID marks and if it is removed,look at the rings and grooves and see if they match the other piston.

The grooves will cause serious loss of compression.
The gouges look like that because the pin cut a really good groove.
Don't ruin a new gasket trying to get this to run.
Goop up the old if you really want to try.

Depending on how deep the cuts?? You might be able to get it bored and install an over-sized piston.
Or you might have a great parts motor

These 50's actually run on 1 cyl. Not very good but they will run.

Thanks for your reply Jerryjerry05. When I first looked at it I saw the obvious gasket issue. So in my haste I ordered a new gasket from ebay for like $19 shipped. Hoping it would be here before the weekend. Afterwards I looked again and saw the grooves. They are deep enough to catch a fingernail. By looking at a parts diagram, it appears the wrist pin would be vertical with a piston pin spacer on the bottom. Then another spacer on top with the retainer clip on top of that. I think I'll put the new gasket on and see what the compression is. Anybody know what the head bolt torque spec and pattern is for this. I'll look and see if there are any markings on top of the piston and report back.
As i said before I have no interest in using this motor. It wouldn't matter if it was brand new because I can't go above 25 hp on the lake. Now lets just say IF the compression is within 5-10 psi and it appears to run ok in a test barrel. With disclosure of the grooves. What would be the value of this complete motor with PT&T and the remote control. I ask this because I looked up all the main part numbers. Then looked them up on ebay. With only about 75% of them found. I came up with a total of over 2k. That was using the very lowest price for each part. I know it could take some time to sell off the parts, but considering what I paid for the boat, motor and trailer. If I low balled the parts prices I still could get my purchase price back and then some. What say you. Thanks.

The parts are where the $$$$$ is.
The T@T for a 50 is used for the 35-50hp.
It can be sold 200 and up.
The electric motor and pump is where the $ is.That part can be used on all Forces up to 1992/3
If it's a fresh water motor?? They sell better.
Once in salt water, they get real hard to take apart.
Some try to sell them for 4-500 I have bought them for as little as 100$.

The ignition system and lower unit sell real well.
I sold 4 complete units for 120- 150 That's trigger,stator, pack and coils and harness.
Look on ebay, they have a bunch of parts for that motor.
Get an idea what they sell for and list yours cheaper.
But someone might pay more, I just sold them to get rid of them and I knew at that price they'd go quick. They did!!

A gouge that can catch your nail: that's deep enough to warrant a re-bore.

I see on the parts diagram that the 50 used a floating pin(not pressed in like I thought) the clips could have came loose??


I bought a 125 complete for 125$ I made about 800$ for the parts.

Props I sold for 60$ free shipping. The 50 prop isn't worth that but someone might need it real bad??

Had another look at the pistons. No manufactures mark. Just a bullseye looking mark which looks like something from the manufacturing process. Jerry. I figured as much. Since I had already ordered a gasket I'm going to install it. Curious about the compression. Looks like I get to learn how to disassemble a Force 50. It is a fresh water engine. Fairly clean one with few scratches. Should I sell the T&T as a unit or seperate the motor and pump? Thanks.

Sell as a unit.
The actual trim unit won't sell without the pump.
Let me know how the new gasket works?
Compression #s ??
There were thousands sold without the T@T and it should sell easily.
Unless your one of those guys who want a ton O money??
I saw a salt water unit on e-bay for $900
It was on ebay for a LONG time.

Got the head gasket in yesterday afternoon. I cleaned the gasket surfaces, chased the threads, installed the gasket and torqued it down. Just got done checking the compression. Top cyl is right at 130psi. Checked the bottom cyl with the grooves cut in it. Ist try was about 125, 2nd and 3rd trys were about 121. Only at most 10psi differance. Thats with some what of dry cylinders also. Had my homemade spark test on while testing. Had really good spark. I would say this thing would run.
As I said before. I think the grooves were there and he was running it unknowingly. Then it starts to run rough and low on power. So he takes it in and they point out the grooves. Either they didn't notice the blown gasket or they didn't tell him. Either way, he walked away considering the motor junk.
I don't know if I want to spend the time to try to start it. I need to get it off the boat. I'm also having some health problems so my energy is limited.

If it's still on the boat and everything's hooked up, start it.

Take a tea spoon of oil and put it in the cyl. and then do the test again.

The new gasket just might do the trick.

One thing, selling the power head like it is??
I know that I wouldn't buy it.
But the parts are worth a bunch.

It is still on the boat and hooked up. Don't really want to deal with trying to run it. No way to hook up water because boat is in the garage for floor and transom repair. Fuel line is hardened up and don't have a spare line to use. I'd rather spend my energy disassembling it. As I said I'm not doing to well. I'm actually hooked up to a infusion for nutrition. Lost to much weight from colon issues. I probably shouldn't be working on it. Told the wife it's my therapy. So I'm just putzing along. As far as the power head. Would it be better to sell it complete as is or break it down into parts. I'm not looking to make every dime I can on it. Just want to compromise between the effort and the return. Thank you so much for your input.

Being fair: sell the power head as is, just make sure they know there is damage.
Explain the issues and give them the new comp results.
The individual pieces will set on your shelf for years.

Now the BIG question???? is the wrist pin still loose?? and making the groove deeper???
To find that, I think a disassembly is needed?

But get the parts listed on e-bay and where ever you want to list.

Summers coming soon and people are working on the big jobs and your T@T unit will sell quickly.

Good luck.

let me know about the comp #s

Thanks. Going to start disassembly today. Been trying to strip the boat down also. Got the sole/deck out so it can be drying out. Got lucky in that only a little bit of the poured in foam near the transom had to come out.

If the foam is water soaked i would go ahead and pull all the old foam out and pour in some good closed cell foam once you get the new deck in.

The worst of it was from the stern to the first rib on both sides. I cut it out, then cut into it to see how far it was wet. It was wet for about 1/4" or so on the bottom in that section. About the height of the bottom of the drain plug. I have a fan blowing on the rest of it to help dry what little else is left. I may even pull it out into the sun and let it cook off. Proves that when stored outside that if you at least keep the boat covered, remove the drain plug, and jack the boat up to tilt it. You can minimise the water intrusion. Ripping all this out gives me the chance to put the boat on a diet and do a layout that I want. One reason I wanted a different boat was because my current 14" 2" alum runabout doesn't have any rod storage or a live well. This boat I can put in a infloor rod locker and has a live well.

I cut up a 21ft. Bayliner center console.
The transom was bad along with the built in tank.
I used the good parts on an identical 21 I'd bought to replace it.(the one in my avatar)

The flotation was so wet it must have weighed another 500#
Some foam was 6-8" thick and it was completely soaked.

This boat is a 1984 Smokercraft Big Fisherman 15. When they built it they put the sole down, then drilled 2" holes spaced out in the plywood and then poured the expanding foam in the holes. But they never sealed the holes, just put the carpet over it. I pulled the carpet out I thought, oh no it's going to be soaked. All I had to do was cut a cone shaped plug out where each hole was. I was so happy I didn't have to dig all that foam out. I did have to trim the foam back cause it bulged out every where. Got it nice and square now. Putting the boat on a diet. So I'm gonna uses use Nidacore glassed on both sides for the sole. No carpet either. Took out the side console and going to tiller steer. That opened up the deck space a lot for fishing. Now the wife and I can sleep in it it we want also.
Back to the subject some. When I tilt the motor up, it will leak back down after awhile. Is this normal or is the cylinder leaking?

That leak down is usually the pump.
In the bottom of the pump, there are 2 very tiny rubber seals.
They go bad and allow the oil to leak past. Thus the drop.

If you try to fix it?? the only thing that you can service is the seals.
DO NOT TOUCH THE PUMP ITSELF!!!! You'll be buying a replacement.

Here's a couple links to the repair.
You can also look on u-tube, there might be video's to help.
Just be VERY careful as you can ruin the valves easily.
They can be hard to take apart

I repair the valves $50 and free shipping.

http://forums.iboats.com/forum/engi...e-hints-on-the-t-t-repairing-the-relief-valve
http://forums.iboats.com/forum/engi...outboards/659768-88-force-85hp-trim-drop-help



I might know someone who'd buy the unit.
Any idea how much $$ you want??
Send me a PM with the details and I'll get you his info.
We shouldn't buy/sell on the site.

PM sent. I hope. I not going to try to fix it. To much going on for that.

Pics of the 3 jaw.

Make sure you leave the top nut on or the wheel can go flying and hurt you.
Heavy gloves and glasses.
Like I said an acetylene torch on the top of the crank will help.

Install the 3 jaw and use an impact wrench and tighten the crap out of it.
Then hit the top of the screw with a 3-4# hammer, it should pop off.

The wheel in the pics, it never did come loose.
I ended up cutting it off in pieces.
That's the only one I didn't get off.
The others all came off, some not easy some real easy.

Got it off. Just needed better bolts. I used what I had on hand and one popped. Got better bolts and put more pressure on it with a few wacks from 1/4 pounder did the trick.