125hp Force cylinder #3 repair

[jerryjerry05]

Remove the plenum on the lower cowl.
4 tiny screws and LOTS of room.

 

[Sandy-man]

Well, with all the spare time I have on my hands right now I finally got around to tackling this job. I currently have the head, carbs and all mounting hardware and #3 piston removed. The number .030 is stamped into the crown of all 4 pistons. I'm assuming this means all 4 cylinders have already been bored out to .030 OS in a previous rebuild. The gouges in #3 cylinder wall don't feel like they are too awfully deep, but if they are more than .005 deep can I safely assume I will need to find a replacement cylinder block?

 

[Sandy-man]

Once you get up to .040 over then you get into rejetting the carbs.
The block removal, the exhaust pipe, held on with 4 bolts.
One of them usually breaks. I just don't take them off and remove the adaptor plate and pipe as an assembly.

I have a tree I use to lift the motors.
Or make a lift out of 4x4's
The blocks not heavy, just awkward.

A small fine rat tail file can do the job of beveling the edges.
You don't need to remove much at all.

Do I need to remove all 4 pistons in order to separate the cylinder block from the crank case? I can see where putting all them needle bearings back in place through the carb ports will be challenging.

 

[The Force power]

Do I need to remove all 4 pistons in order to separate the cylinder block from the crank case? I can see where putting all them needle bearings back in place through the carb ports will be challenging.

Jiggs You have the skills / hands of a surgeon to do that, :hail:Man I would not even attempt

I did a 90 HP 3 cyl. this winter But I pulled & split the block for the necessary reasons.

 

[jerryjerry05]

The best way is to split the block.
Use needle bearing assembly grease when you reinstall.
Any other grease won't release/melt as quickly as needed.

IF??? you can hook a nail in the grooves??? Then it needs another bore job.

Once you get past .030 and up to .040 and above you need to start rejetting the carbs.

Look for a new block or even a complete motor.

Saw one on FB in Fl. complete 200$ Look around.

 

[Sandy-man]

The best way is to split the block.
Use needle bearing assembly grease when you reinstall.
Any other grease won't release/melt as quickly as needed.

IF??? you can hook a nail in the grooves??? Then it needs another bore job.

Once you get past .030 and up to .040 and above you need to start rejetting the carbs.

Look for a new block or even a complete motor.

Saw one on FB in Fl. complete 200$ Look around.

I'm assuming you mean I must remove all 4 pistons before splitting the block. I was hoping to be able to leave them intact and slide the block back onto them once boring of cylinder is complete.

Another question: I cannot get the flywheel off, tried pulling it with my 3 jaw puller, applying some heat, but not a lot for fear of screwing up the stator, at the base of the crankshaft, no go. Will I be able to split the block with the flywheel still on?

I'm hoping the carbs were already rejetted when all 4 pistons were replaced with .030 OS ones. I can probably pull one of the main jets jets to see if they are original size or larger. I'm assuming there will be a number stamped in the jet like there is for motorcycle carb jets.

I've been watching on Facebook marketplace for another 125 Force motor. I found one in Kentucky but it sold before I could get down there to get it. Is there a good sale listing source you can recommend I check out?

 

[Sandy-man]

I just read a bunch of other posts from several years ago regarding difficulty removing the flywheel and now know I will need to buy a harmonic balancer puller and don't be afraid of using more heat and a much bigger hammer on the puller center bolt. I am determined to get this done.

The grooves in #3 cylinder wall will require being bored out and I'm pretty sure going to .040 OS should do the trick.

Will pull the main jet out of one of the carbs over the next couple days to see if the previous rebuild included rejetting. Fingers crossed

 

[jerryjerry05]

The harmonic balance puller usually requires the 3 holes be drilled and tapped to the next size.
!/4 20 to 5/16-16???
Myself I never had much luck with that kind of puller, the 3 jaw almost always did the trick, one time it didn't work(nightmare).

You can split the cases without the pistons coming out.
It's just easier to handle when sending to a shop for boring.

Heat on the crank end shouldn't get hot enough to hurt the stator.
Don't get it so hot it turns red.
You should replace the seal under the stator sop.
A little heat where you see sillycone helps release the 2 half's.

Where do you live?

 

[racerone]

???------You have to remove the power head.----Then split the crankcase and block.-----Then remove the pistons / rods and crankshaft.----Not sure why folks are always looking for a short cut.

 

[Sandy-man]

The harmonic balance puller usually requires the 3 holes be drilled and tapped to the next size.
!/4 20 to 5/16-16???
Myself I never had much luck with that kind of puller, the 3 jaw almost always did the trick, one time it didn't work(nightmare).

You can split the cases without the pistons coming out.
It's just easier to handle when sending to a shop for boring.

Heat on the crank end shouldn't get hot enough to hurt the stator.
Don't get it so hot it turns red.
You should replace the seal under the stator sop.
A little heat where you see sillycone helps release the 2 half's.

Where do you live?

I live in southern Michigan. I will need to get a bigger 3 jaw puller than the one I have, it's not wide enough for the fingers to get under the flywheel gear. When I tried using it a couple days ago I actually broke a small piece off the aluminum casting of the top rim of the flywheel, I didn't realize it was aluminum until it broke. I will need to get it balanced, I might try to weld the piece back on using the new nonmagnetic welding rods I've been seeing advertised on FB.

Thank you, jerry05. I really appreciate your advice. After reading all the different posts on here from many years back I realize you have been doing this kind of work, and helping others, for quite a spell. That's very kind of you.

 

[racerone]

A 3 jaw puller may be totally the wrong puller to use.----Are there 3 threaded holes near the flywheel nut ??-----First I have heard of -----" non magnetic welding rods " ---tell me more.

 

[Sandy-man]

???------You have to remove the power head.----Then split the crankcase and block.-----Then remove the pistons / rods and crankshaft.----Not sure why folks are always looking for a short cut.

I have pulled the powerhead and still trying to split the crankcase and block, just having some problems removing the flywheel. I've never worked on a outboard motor before but have done enough to be dangerous on motorcycle motors. I am one to not take anything apart that doesn't have to be, some call it being lazy, so I was simply trying to save myself a bunch of time and headaches putting all 4 pistons and rods back in place. Apparently that's not going to work so well? Not even remotely close to a 2 cylinder motorcycle. I have a lot to learn here but willing and ready to do whatever is necessary.

My book, which is actually for 1984-1986, 85 & 125 hp, isn't real descriptive with this process so wondering how the much more experienced folks do it. I appreciate any helpful tips anyone can provide.
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[Sandy-man]

A 3 jaw puller may be totally the wrong puller to use.----Are there 3 threaded holes near the flywheel nut ??-----First I have heard of -----" non magnetic welding rods " ---tell me more.

https://www.facebook.com/SimpleSolutionNow/videos/736504303443620/

Hopefully I successfully copied and pasted the link to the welding rods I mentioned.

 

[Sandy-man]

A 3 jaw puller may be totally the wrong puller to use.----Are there 3 threaded holes near the flywheel nut ??-----First I have heard of -----" non magnetic welding rods " ---tell me more.

Here's another link, hopefully it works.

https://quietson.com/products/solution-welding-flux-cored-rods

 

[racerone]

?----I am going to blunt here.------Those rods are not ---" new " ----I started using that stuff back in about 1981 I believe !!----You have you be careful on a flywheel as there are magnets that could be damaged at 800 degrees F.

 

[Sandy-man]

?----I am going to blunt here.------Those rods are not ---" new " ----I started using that stuff back in about 1981 I believe !!----You have you be careful on a flywheel as there are magnets that could be damaged at 800 degrees F.

The flywheel does have 3 threaded holes around the flywheel nut. I just got back from shopping and bought a 3 bolt wheel puller instead of a vibration dampener puller.

I wasn't aware of these aluminum welding rods until about a year ago, never had any need for them until now. Watching and listening to the commercials it doesn't look like a lot of heat is needed for them. Also, the broken piece being way out on the edge of the wheel should lessen the possibility of getting it too hot where it counts, I think.

Here's a pic of the break

 

[jerryjerry05]

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"​

 

[The Force power]

The flywheel does have 3 threaded holes around the flywheel nut. I just got back from shopping and bought a 3 bolt wheel puller instead of a vibration dampener puller.
Here's a pic of the break

Was this caused by the puller?? or Hammer?

IF....using a 2-3 claw puller you need to put the claws at the bottom
IF.....using the threaded hole; make sure you buy the strongest grade-bolts possible (do NOT rely on the supplied in the kit)

 

[Redbarron%%]

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.

 

[Sandy-man]

Was this caused by the puller?? or Hammer?

IF....using a 2-3 claw puller you need to put the claws at the bottom
IF.....using the threaded hole; make sure you buy the strongest grade-bolts possible (do NOT rely on the supplied in the kit)

The puller broke it. I think I have some good quality bolts to use instead of the ones that came with the new puller kit. Thanks