Lucky new force 125 owner ;) first outboard 2 stroke jet engine for me.

[chestypuller]

well here i picked up a flat bottom fishing boat for rivers, it has allot of character to say the least... included in the character is the dreaded 125 force from 1989 ive been reading so much about... with a blown headgasket on #3 piston ive revealed.


ordered the new headgasket and used head bolts since one broke( still need to drill the remainder out of the block)

Im a newbie, but this sure seems like a simple engine.

one question i have is, is the waterpump impeller for the cooling in the jet unit itself? and is it a different part number then the propeller version? i wanted to get one on the way but want to make sure its the right one before i have it shipped to Alaska.

 

[MickLovin]

Make sure you find the reason for the blown head gasket on #3 first, Frank Acampora may be able to help with the Jet version, I haven't seen a Force with one on but others may have, I have seen the Johnson version.

 

[chestypuller]

compression tests revealed the blown head gasket. looks like it was just lack of maintance but ill check into it, #1 piston has some mechanical damage, but cylinders 1 2 4 all read in 120s for compression testing


#1 piston

#1 bore

failed head gasket

Head

what are these hoses for? and i think they look old enough i want to replace them peeling paint on them or something? maybe just falling apart
i know the large ones the fuel line. im talking the smaller looking ones

thanks

Skip

 

[chestypuller]

got all the headbolt holes threadchased and removing the broken bolt. almost there

 

[Frank Acampora]

First: #1 piston shows denting from most likely a broken ring. The semi-keystone top rings on these engines broke with more than occasional frequency. The head also shows damage from a broken ring banging around inside for a while. SO, you definitely want to check #1 piston before putting the engine together.

There is nothing wrong with the oil recirculation hoses. The factory decided to paint the engine after they were installed and we all know how well paint sticks to rubber--especially rubber that has not been specially primed.

I never worked on a jet drive Force but I suspect that water supply would be taken from the high pressure side of the jet pump. I doubt that a true water pump was installed in the jet pump. If by some chance it does have a true water pump, the impeller would very likely be the same as the prop drive---if the jet drive is stock.

 

[chestypuller]

No Title

Thermostat housing flat head screwdriver bolts are really being a bugger. im thinking about grinding the heads off them if i cant find my impact screwdriver soon!

all the bolt holes have their broken bolts extracted now in the block and head. threads are good.

I think this piston will be staying in there for the rest of this season then this winter it will be a total tear down and rebuild. may just leave the thermostat and the impeller for then also. lots of loose bolts or stripped on this lower unit, uncluding a crack in the jet housing that was repaired once before it looks like.

good to know on hoses.

the engine block is a pretty metal flake purple it looks like anyhow.

 

[chestypuller]

No Title

Thermostat housing flat head screwdriver bolts are really being a bugger. im thinking about grinding the heads off them if i cant find my impact screwdriver soon!

all the bolt holes have their broken bolts extracted now in the block and head. threads are good.

I think this piston will be staying in there for the rest of this season then this winter it will be a total tear down and rebuild. may just leave the thermostat and the impeller for then also. lots of loose bolts or stripped on this lower unit, uncluding a crack in the jet housing that was repaired once before it looks like.

good to know on hoses.

the engine block is a pretty metal flake purple it looks like anyhow.

 

[chestypuller]

No Title

heres the cracks in jet

 

[MickLovin]

From what I have seen of the jet drive, they have a pump and impeller not much different to normal, well thats what the Johnson's look like.

 

[MickLovin]

Personally I think you will be wasting a head gasket by not looking further into #1's problem

 

[jerryjerry05]

DON"T fix it half way.
That piston's gonna bite you in the butt.
The pump has an impeller.
The cracks in the pump housing if they are sealed aren't a problem.
Looks like you need to take the whole pump apart and see if there is any damage to the pumps impeller(not the water pump).

The thermo housing.
The screws can be worked out.
A propane torch a small hammer and PB Blaster or WD-40.
Spray, heat and tap on the head of the screw.
Don't hit so hard you deform the slot.
Hit with the right sized screwdriver in the slot.
Repeat the process a few times.
Tap on the side of the housing and spray and heat and tap and spray.
It took me about 2 hours to get 1 screw loose. But I did.

I might have a piston.


You say comp is 120 on 1 2 4 what about #3.

 

[chestypuller]

DON"T fix it half way.
That piston's gonna bite you in the butt.
The pump has an impeller.
The cracks in the pump housing if they are sealed aren't a problem.
Looks like you need to take the whole pump apart and see if there is any damage to the pumps impeller(not the water pump).

The thermo housing.
The screws can be worked out.
A propane torch a small hammer and PB Blaster or WD-40.
Spray, heat and tap on the head of the screw.
Don't hit so hard you deform the slot.
Hit with the right sized screwdriver in the slot.
Repeat the process a few times.
Tap on the side of the housing and spray and heat and tap and spray.
It took me about 2 hours to get 1 screw loose. But I did.

I might have a piston.


You say comp is 120 on 1 2 4 what about #3.

3 was the blown headgasket cyl it had zero compression

I got anothrt engine im trying to get working to use so I can just rebuild this ine for next year now

 

[chestypuller]

Woukd b nice to just r&r all rings and #1 piston then hone tge cly. They still have hone marks in them now so cant be that nany hours on it

 

[Frank Acampora]

Unless there is noticeable damage to them, it is useless to replace rings. Since the cylinder gets a fresh shot of oil each revolution rings--even on high hour engines almost NEVER wear beyond use. The top rings on these engines DO tend to catch in the exhaust ports and break. Often they will do very little damage to the cylinder but the piston is usually damaged.

I understand that money and time is always tight BUT: Why is there NEVER enough time to do it correctly and ALWAYS enough time to re-do it?

If you don't at least look at that number 1 and evaluate it, yes, it may run well for a while but sooner or later it will turn around an bite you in the A** Murphy says that this will happen at a time when you need full power. Take the advice of those on this board who have been there, done that, bought the tee shirt, wore it, washed it, and threw it out.

 

[chestypuller]

well pulled the motor off the boat, that was a task in itself..

pulled the jet unit off.. got a guy that has one for sale gonna see if its same bolt pattern.. he dont know what its off of.

gonna pull the engine off the lower unit next so i can pull it apart on the engine stand.

 

[chestypuller]

well the used unit is smaller, so im just gonna buy another welder thats aluminum capable and weld it up again. will need on anyhow as bad of shape this boats in, plus i can modify things then. might have to wait tell christmas to get it tho! lol