My turn to rebuild a Force (with some pics)

[foxtrotboss]

After reading some threads here and some advice from Frank, I decided it was time to rebuild my 23 year Force 125 four cylinder. #2 cylinder is scored really bad about a 1 inch wide section top to bottom scored bad but has compression of 120 go figure. #3 cylinder has a ring that has broken loose and is coming out the top of the piston with a compression of 75 and lightly grooved wall. I also think by observation so far that the 3 cylinder operates the fuel pump by vacuum.
So after much mental debate I began the tear down of the powerhead. I am almost ready to lift the powerhead off. I need to get a flywheel puller first and finish taking all that under it off. And remove the bolts holding it on.
Then when it is on the ground I'll strip the block and send it to the machine shop.
There really isnt much to one of these motors I am really amazed how simple of a motor they are. Once the block is at the machine shop I will begin removing all the old gasket that is stuck tight. Also going to locktite the reed valve screws, I have enlisted my 12 year old son in the rebuild also, so I will have him chase screws with the tap to clean the threads.
I have read the threads on the three cylinders and I hope this will go as well as theirs. I had my son label all the wired with electricians number tape so we can get them back where they were.
So once I find out what the cyclinders are bored out to I am going to order a rebuild kit. I found one kit online that includes all the pistons and bearings and gaskets. Is there a reason why I shouldn't replace everything possible?

Here is the link to the kit does anyone see why I shouldn't get it?

http://www.powerheadkit.com/images/reman kitforce4-800.jpg

Sorry I don't have any pictures yet but tommorrow I should be able to have some.


Scott

 

[Frank Acampora]

Re: My turn to rebuild a Force

Re: My turn to rebuild a Force

Factory recommends replacing bearings however, I have not yet replaced bearings on an engine I have rebuilt. See: bearings are "dead hard" when new and unless they show signs of damage (spalling,pitting, corrosion, etc) then they are like new and do not need to be replaced. While bearings do have a shelf life AND a service life, in an outboard that has been kept properly oiled it will NEVER approach the running time needed to reach the service life limit. The chances of a used bearing lasting the life of the engine are reasonably good.

Logic tells me "Why should I replace the bearings when I am not replacing the races they ride upon?"--crankpin, rod ends, center crank journals, and bottom journal. AND, because of the necessity of a really big press, I will be willing to bet that the rebuild kit does not contain an upper crank ball bearing. Additionally, used rollers in good condition usually have "work hardened" just a bit more and should actually be superior to new. However: Yer pays yer money, Yer takes yer choice!

However: As far as pistons, you already need to bore two cylinders so for a couple of bucks more, (OK, about 150-175) you may as well do all three. gaskets? can't go wrong installing new ones. Top crank seal? may as well install a new on for the 20 bucks it costs. Beats needing to remove the flywheel and electrical to replace it at a later date. Same for the lower crank seal. Who wants to remove the block from the leg just to replace a seal?

 

[foxtrotboss]

Re: My turn to rebuild a Force

Re: My turn to rebuild a Force

Well tonight the fly wheel did not come off. The bolts in the puller gave out, I was using grade 5 bolts but tommorrow I will use grade 8 bolts and heat LOL. Also going to let the flywheel soak with penetrating oil. Then maybe I can get the flywheel off. Just going easy so as not to damage any parts

 

[Frank Acampora]

Re: My turn to rebuild a Force

Re: My turn to rebuild a Force

Probably not the bolts, probably your method. I use stainless with no problems breaking bolts.

Run the bolts all the way in so you don't strip the flywheel holes. If you have an actual pointed center bolt, run the center bolt into the depression in the crankshaft snout and tighten grunt tight. If you don't have a pointed center bolt, put a steel cushioniing plate between the bolt abd the crankshaft so you don't **** up the threads. Then either heat the center of the flywheel or smack the S**t out of the top of the bolt with a heavy hammer. 16 ounce toy will not work as well. If it doesn't work the first time, tighten some more and do it again.

All but the most stubborn flywheels will come off.

Friens of mine uses a steerong wheel puller or harmonic balancer puller with an impact gun. Vibration of the gun pops it right off--no heat, no smacking. I need to try that but I am too lazy to turn on the compressor.

 

[foxtrotboss]

Re: My turn to rebuild a Force

Re: My turn to rebuild a Force

Thanks tomorrow I will have the torch and compressor ready, and what the heck I have a 24 oz dead blow hammer too. I am just taking my time, I plan on this to take two weeks or so. That could be because I going to have surgery friday. So I was hoping to have the block to the machinist by friday, then after recovery put it back together.

 

[foxtrotboss]

Re: My turn to rebuild a Force

Re: My turn to rebuild a Force

Well tonight the flywheel came off with one little tap. I took the block apartand removed the pistons. well two pistons are shot and the other two have seized bottom rings. That will be four new pistons and rings for me. I need to remove the exhaust valve and the covers on the fuel pump side of the motor then it will be ready to go. I guess.

 

[foxtrotboss]

Re: My turn to rebuild a Force

Re: My turn to rebuild a Force

ok problem here there are three flat metal ring type crankcase seals around the crank inbetween each cylinder. Well my helpful 12 year old son just damaged them where can I get more? will the motor run without them? and why is it the little parts that hurts so much.

Scott

 

[pnwboat]

Re: My turn to rebuild a Force

Re: My turn to rebuild a Force

Those are the crankcase seals. Each section of the crankcase for each individual cylinder is supposed to be sealed from each other. Very common and easy to break. Done it myself. Item # 11 below. I usually keep a couple of extra just in case I break one. Without them, motor probably won't run as well as it should. The crankcase area gets pressurized on the down stroke of the piston to pump the next load of fuel/air into the cylinder. The seal is used to maintain pressure within that section of the crankcase.


http://www.crowleymarine.com/mercury_parts/1227/8.cfm

 

[foxtrotboss]

Re: My turn to rebuild a Force

Re: My turn to rebuild a Force

Assement time all I have now in the motor is time:

all the pistons have a 1 stamped on the top does that mean they are already 10 over?

One piston has groves up and down on one side and the cylinder wall matches. What does that mean?

All the pistons had at least one ring seized.

The water pump and tube had reastricted flow from silt, previos owner I guess I never was in water less than 10 feet and it was a lake. River running I guess from previous owner. I have ran in a lake for the three times I had it out since 7-4.

The motor has fresh gaskets almost everywhere.

At least to hole need bored.

Opinions please


Thanks Scott

 

[ezez]

Re: My turn to rebuild a Force

Re: My turn to rebuild a Force

I believe you are correct in that the pistons are already over sized 10 thousandths. The fact that it has been rebuilt once before isn't a deal breaker IMO. In fact, I don't really think it matters at all.

The grooves are probably from grit invading the cylinder.

As far as reboring the holes a machine shop will give you more info on what need to be done. It cost me $50/hole to rebore but I got quotes as high as $85/hole. Not every machine shop will mess with these motors so, make sure you are clear with them what it is and the fact that they have blind holes.

For Wiseco pistons/rings you are looking at $100ish for each.

You have the engine apart at this point so, cleaning it up shouldn't be too difficult.

You'll just need to decide if throwing $$$ into rebuilding is worth it. I contemplated parting mine out on Ebay. I figured I could have generated around $500 by parting it out to apply to repowering with another motor. I eventually just decided to rebuild mine. Good Luck.

 

[foxtrotboss]

Re: My turn to rebuild a Force

Re: My turn to rebuild a Force

Ok found a machine shop 42.50 a hole.

They offered to sell me J&E or LA sleeve pistons never heard of them are they any good? What bearings do they use?

Wiseco seems to be the prefered choice are they that much better?

 

[ezez]

Re: My turn to rebuild a Force

Re: My turn to rebuild a Force

I really don't know about aftermarket pistons but I think the reason Wiseco get recomended is that you don't need to use a press for the wrist pins. This makes it easier for the weekend mechanic to use them. In addition, the pistons are forged and the rings are good quality.

$42.50 a hole sounds real reasonable.

 

[pnwboat]

Re: My turn to rebuild a Force

Re: My turn to rebuild a Force

J&E pistons make high quality forged replacement pistons for automotive and jet ski motors. I do not see any listings for outboard motors though. I've used forged J&E pistons with floating wrist pins for automotive applications and the quality is excellent. Never heard of LA Sleeve. No listings on-line for outboard motor pistons. Can't comment on LA Sleeve.

I would ask the following questions about the two makes of pistons.

1. How much?
2. Are they forged or cast?
3. Do they use floating wrist pins and are they included w/piston?
4. Do they require different wrist pin bearings from stock?
5. Do they include rings and are they file fit or just standard end gap.

 

[foxtrotboss]

Re: My turn to rebuild a Force

Re: My turn to rebuild a Force

Wow I didn't realize they were forged but again forged vs cast. Wiseco makes both 25 dollar difference.

This motor looks like it is going back together to live another day LOL

 

[foxtrotboss]

Re: My turn to rebuild a Force

Re: My turn to rebuild a Force

I say I would post some pictures so here what I could do.

sorry about the quality of the pictures it was taken with my phone.

 

[foxtrotboss]

Re: My turn to rebuild a Force (with some pics)

Can anyone explain what the thin peice of metal in the exhaust valve does?

 

[pnwboat]

Re: My turn to rebuild a Force (with some pics)

Are you referring to the sheet of stainless steel inside the exhaust cavity that is sandwiched between the exhaust cover and block? If so it forms the water jacket so that water can circulate behind it to cool the exhaust gases down. I would imagine that without it, the outer exhaust cover would get extremely hot. I guess they use stainless steel to minimize corrosion.

 

[foxtrotboss]

Re: My turn to rebuild a Force (with some pics)

yes thats the onw mine is warped but I think it will still work as a water jacket. Didnt realize that was a water path.

 

[yfz450guy]

Re: My turn to rebuild a Force (with some pics)

hey, when you get the final number on the rebuild let us know. i have an 1988 125 and i am debating about a rebuild this winter.
thanks and keep up the good work.

 

[pnwboat]

Re: My turn to rebuild a Force (with some pics)

They usually are warped from the heat of the exhaust. I replaced mine with a piece of slightly thicker stainless steel. Had to cut and drill it. That stainless steel is some tough stuff. Last time I had my exhaust cover off it did not show any signs of warping though.