125hp Force cylinder #3 repair

[Sandy-man]

The older flywheels: the magnet is a long strip about 1 1/2" by 20"???
It's far enough away the heat from the center won't affect it.
When I rebuild, I remove the magnet and clean the old glue off both pieces.
Super glue, Gorilla glue on the broken piece.
GG expands when used so very little is needed. SG works good.
The center of the magnet has 2-3 pieces of magnet in it. Getting them hot doesn't seem to affect them.
But then I never got them so hot they melted???
Harbor Freight has a big 3 jaw puller and a 3-4 puller set. Get the one with the biggest jaws.8" works good.
ebay

352997554501 or 233245475047 both about 20$ both have an 8"​

Since I already bought the 3-4 bolt puller I will try with it later today. If I still can't get it I guess I will make another trip to Harbor Freight and get the 8" 3 jaw puller.

Have you had to glue a piece back on a flywheel before?

 

[Sandy-man]

Use the hardest bolts you can find and make sure you clean out the threads and get full engagement of the bolts.
I have used an impact wrench to drive the puller, but a nice long handle and flywheel holder with an extension might be necessary.
I have had to put thread inserts in to replace the buggered up threads when I used the bolts with a Chinese puller making a hard job harder.
Also make sure you grease the puller bolt as well to make turning it as easy as possible.
I haven't seen an aluminum flywheel my self, but it one exists then heating the center to 200F might loosen up the grip between the flywheel and crank. Not so much if cast iron flywheel and steel crank as the coefficient of expansion is too close to the same.
Try to not hit anything with a hammer as if cast iron you can crack the flywheel and have it fly apart to endanger the people nearby. Also there are the bearings that will dent the races (very slightly, but still damage) especially if you hammer down on the engine.

This flywheel is most definitely cast aluminum. The only place I hit with my 4 pound hammer was the top of the puller bolt and the bottom of the flywheel on the steel ring gear, being careful not to hit any of the teeth. I believe my impact wrench will be plenty powerful enough to put more than enough torque on any puller bolt. Grease on the puller bolt is a good idea, thanks.

 

[racerone]

??----Do not use a 3 arm puller !!

 

[Redbarron%%]

When you hit the bolt on the puller you drive the crankshaft down, ramming the inner race against the balls and those balls against the outer race, basically and probably damaging the bearing. point contact hard steel against hard steel. This bearing is the thrust bearing for the crank.
The flywheel should not be repaired as it is a hazard when rotating at high speed.
Do not use a three arm puller. There are threaded holes in most flywheels for the puller.

 

[Sandy-man]

Done, it's completely torn down. The 3-4 bolt puller and impact wrench did the trick in about 2 seconds flat.

Cylinders 1 and 2 also have some very mild scratches as well as a spot on both pistons. Looks like the rings are scratched a bit too. Will need to hone those cylinders and replace the rings, I believe. Cylinder 4 looks unscathed.

Next up, take the block into the shop to see if boring to .040 OS will clean up cylinder 3. If it does then I'm pretty sure I can make this motor whole again.

Since I got no alarm of any sort when it overheated or temp gauge, how can I prevent overheat if the pump key dislodges again? Is there supposed to be an alarm, indicator light or something? Seems like there would be since it has a temp sending unit. My book shows nothing about it except in the wiring diagram it shows temp indicator.

 

[racerone]

The alarm buzzer is shown in the control box.-------But it is an optional item.------Imagine that.----Perhaps the kit is available somewhere.

 

[Sandy-man]

The alarm buzzer is shown in the control box.-------But it is an optional item.------Imagine that.----Perhaps the kit is available somewhere.

Thanks, racerone. I'm going to see if I can get my hands on a owners manual for the boat. Perhaps it can lead me to what I need for an alarm, or maybe a parts supplier like iboats, Marine engines, or some other. Do you have a favorite parts supplier?

 

[racerone]

Any buzzer will do.---+ wires are easy to find.------The sensor from a Mercury / Johnson / Evinrude / Yamaha may also work.

 

[Nordin]

You can use any kind of buzzer/horn that need 12VDC supply.
A motorcycle horn would be good and give a loud sound.
If you connect a light parallel with the horn/buzzer you have two indicators for overheat.
The sender in the head (orange wire) is only a switch (off/on).
Connect +12VDC from keyswitch (if you want to turn the power off for the horn/light) at one post of the horn/light and connect the sender wire (orange) to the other.
The sender grounds when overheat occurs.

 

[jerryjerry05]

Most older Forces and even Mercury the buzzer wasn't in the shifter box.
It was added to the harness under the dash by the ignition key.

I used a motorcycle horn and a car horn to replace the small ineffective one installed from the dealer.
Make sure it's wired right or it won't work.
ALL the harnesses has a lead for the horn it connects direct through the temp sensor on the block.
Like Nordin said, Orange is the lead.

 

[Sandy-man]

Thanks, everyone. I think I will go with a car horn, they are much louder than a motorcycle horn. My hearing isn't nearly as good as it used to be, too many years of questionable hearing protection running chainsaw and lots of target shooting. Not to mention that motor isn't very quiet when on plane.

 

[Sandy-man]

Well I just got word from my machinist who was going to bore cylinder 3. My block is no good. I found several on eBay, one that the owner claims all 4 cylinders look very good and still at standard bore size. Once I get it will have my machinist look it over do whatever is necessary, hone and/or bore. So I know I will need to replace all of the pistons and rings. Is there a parts supplier that sells a complete engine gasket/seal kit or will I need to order all separately. I don't see where Marineengines.com have a kit and pistons are $100 each.

What's your favorite go-to force parts supplier?

 

[The Force power]

first get the block ready, bore to whatever then shop for pistons.
you can here on Iboats if they have, otherwise Ebay sell complete sets including all gaskets/pistons/rings

 

[jerryjerry05]

What I use is Wiseco pistons.
More expensive but way easier to use.
The OEM pistons need a special tool to be able to use them.

With Wiseco you'll need to buy their rings and wristpin kits.
Way easier to assemble.

Take the block and see what work it needs?
If it needs a bore job? ask the machine shop what size they are boring it out?
010 over? .020????
Ten buy the parts and take them to the shop and let them do the bore job.

Don't know WHY your old motor took a dump but EVERYTHING needs to be gone through.
The recirc system and the exhaust ports, carbs, etc.

The exhaust ports the new gaskets will need special attention.They don't always seal right.

Let us know what's going on??

 

[Sandy-man]

What I use is Wiseco pistons.
More expensive but way easier to use.
The OEM pistons need a special tool to be able to use them.

With Wiseco you'll need to buy their rings and wristpin kits.
Way easier to assemble.

Take the block and see what work it needs?
If it needs a bore job? ask the machine shop what size they are boring it out?
010 over? .020????
Ten buy the parts and take them to the shop and let them do the bore job.

Don't know WHY your old motor took a dump but EVERYTHING needs to be gone through.
The recirc system and the exhaust ports, carbs, etc.

The exhaust ports the new gaskets will need special attention.They don't always seal right.

Let us know what's going on??

The water pump key slipped out of the keyway somehow and jammed up the pump, while on plane in the middle of Lake Erie. Overheated and shut down. My machinist said he got some weird measurements in a few of the cylinders that were supposed to be only bored to .030 OS but in many spots measured in at up to +.039. Therefore not leaving enough to bore to max OS of +.040.

My biggest concern is why/how the key did that and what's to prevent it from doing it again. I already installed a new pump kit and didn't see any damage to the key or keyway. ??? Is this something that should be done on a fairly regular basis?

The used block I bought is coming with both halves, I will check them both thoroughly and use it as opposed to only the cylinder block.

 

[healey8390]

I personally think the Chrysler/Force impellers are flimsy and wouldn’t run them more than a year in my opinion. I had one spin on me on my 83’ 4cyl 90. KeY was in place, rubber spun off metal. The bottom line is you need to make sure the overheat sensor and buzzer works. Trust me I blew out a 2nd engine (86’ Johnson 110)a couple years ago because the alarm didn’t sound so I’m not taking any chances this time.

 

[jerryjerry05]

Glue the key in place, Gorilla glue.
Make sure it cures before the impeller goes in.
Over the years the used 2 different impellers, the new will fit into the old housing, fits loosely but fits.
The old won't fit into the new housing with the steel insert.
Since 1986 I have never seen an impeller have a key slip or the hub let loose.

The best thing I suggest is get a car or motorcycle horn to upgrade the alarm system.
The OEM buzzer is too weak and can't be heard when running fast.
Get a fancy horn and install it next to the boat horn, some install a light that flashes when hot.
Myself, I get sick if I spend too much time looking at the dash

 

[Sandy-man]

It's too late for any gluing of the impeller key, I rebuilt the lower unit last fall. Since I bought and installed a complete pump kit, I would think the impeller is the correct fit for the pump housing. I will make sure the alarm, car horn, and temp sending unit is working when the rebuild is completed.

 

[Sandy-man]

What I use is Wiseco pistons.
More expensive but way easier to use.
The OEM pistons need a special tool to be able to use them.

With Wiseco you'll need to buy their rings and wristpin kits.
Way easier to assemble.

Take the block and see what work it needs?
If it needs a bore job? ask the machine shop what size they are boring it out?
010 over? .020????
Ten buy the parts and take them to the shop and let them do the bore job.

Don't know WHY your old motor took a dump but EVERYTHING needs to be gone through.
The recirc system and the exhaust ports, carbs, etc.

The exhaust ports the new gaskets will need special attention.They don't always seal right.

Let us know what's going on??

Just curious. Why is it so important that the exhaust port gaskets get changed?

 

[Sandy-man]

Oh, and I found an excellent parts source, which includes wiseco piston kits. boatpartstore.com

If I wasn't so hell bent on rebuilding this motor myself I would send the powerhead to them for rebuild. Cost for complete rebuild is $1995. That sounds pretty reasonable to me.