1989 Force 125 won't go above 3000rpm and doesn't have much power....

[Mellinghouse]

That's a good point. I was wondering whether I'd have to re-jet.

Can you clarify what you are talking about with the exhaust chest?

 

[jerryjerry05]

Port side of the motor.
Big flat cover over the exhaust side.
Look at the edges of the mating surfaces.
Over time they get rounded and need to be cleaned up to seal right.

 

[Mellinghouse]

UPDATE: Ran into my first snafu.

I've got the power head put back together, minus the exhaust port cover. I was very diligent about photographing and documenting parts during disassembly, however, apparently not while I pulled off the exhaust port cover. I do recall it being rather difficult to remove with thick gasket material and a metal plate in between. I assumed the metal plate was part of a two-piece paper/steel gasket when I was removing it, as it is presumably subject to high-heat on the exhaust port. Apparently, this was not the case.

I was rifling through the gasket kit getting ready to install the exhaust port cover and found 4 gaskets that appear to belong to it. This seemed odd, as I was expecting to have a two-piece paper/steel gasket. This caused me to look for a photo during disassembly, which is how I found out I didn't take any. Anywho, my heart sank when I remembered damaging and ultimately throwing away the metal plate that was sandwiched between the gaskets. The four gaskets still seems odd to me, as they cause the exhaust port cover to not mate properly on the block, but maybe the metal plate remedies that. Can anyone help me out with how the gaskets are to be installed, or where to find a reasonably priced exhaust port plate?

Also, it should be noted that I am doing this rebuild without aid of a service manual... (I know, I know... stupid).

 

[jerryjerry05]

OH NO!!!!

The plate can be bought new.
I wouldn't get used.

The reason you have 4 gaskets is they made a bolt pattern change between 87-89.
But according to the parts diagrams yours needs.

EXHAUST PORT PLATE 8197791 boatsdotnet 60$

Buying a used one?? you don't know for sure what your getting??​

 

[Jiggz]

Here's a pic of the power head. I do not have the parts list but it'll give you info on the exhaust plate on item 95, 96 and 97.

 

[Mellinghouse]

UPDATE:

The rebuild is done and it’s time to fire it up, but I ran into a problem. Last night it was acting like the battery was weak (would crank over very slowly and labored), so I put it on a slow charge overnight. Went out this morning and it said it was fully charged, but it still barely turned over. Took it to the battery store and the guy said it was fully charged, but might not be powerful enough, so I bought a brand new more powerful battery. Still barely turns over. I pull the plugs and it cranks over fine, so it doesn’t seem to be a major mechanical problem. But when the plugs are in and there’s compression, it barely turns over.

What could that be?

 

[Mellinghouse]

Well, I was troubleshooting some things and the starter quit spinning and now only clicks. Battery is still fully charged, so it looks like it died. I’m wondering if the starter was on its last leg and just didn’t have the oomph to crank the fresh/tight motor.

 

[Redbarron%%]

Pull the spark plugs and turn it over by hand to see how easily the motor turns over.
If it turns easily spin it with the starter.
If water is in a cylinder the engine won't turn

 

[Mellinghouse]

It's a fresh rebuild that hasn't been run, so there hasn't been water in the system yet.

The motor turns easily by hand when the plugs are out. The starter spins it easily when they're out too. But when the plugs are in and there's compression, it seems like the starter just doesn't have enough torque. Acts exactly like a very weak battery.

 

[Redbarron%%]

It could be a high resistance connection through the solenoid, loose connections, bad brushes, or a bad armature.
A meter check at various points in the circuit and the negative side of the battery will tell a lot.
For example if you measure 12 volts on the battery side of the solenoid and 6 volts on the starter side then there is a lot of drop.
If there is 6 on the starter and the battery side of the solenoid then the battery or a cable from the battery might be bad.
If you have 12 volts or nearly that on the starter then the brushes might not be making good connection.
If the voltage drops a great deal at the starter that would indicate that either the current draw is high or there is a resistance drop in the circuit

 

[jerryjerry05]

First check the ground on the block.
Then pull the starter and open it up.
The brushes could be stuck or the crud build up
is so bad it just don't work.

Is the lower unit on?
If it continues after the starter rebuild, drop the drive and see if that changes anything?
Sometimes a rusty bearing can cause problems.

Worst case: you might have missed a locating pin on the crank bearing??

 

[Mellinghouse]

UPDATE:

I’m happy to report that my new starter showed up and it spins the motor just fine. I hooked it up to water and it fired up as soon as fuel hit the cylinders. I richened the fuel mix and did some rough tuning in the driveway and took it to the lake Sunday.

I launched the boat and took it on a loop while my partner parked the trailer. I noticed the low rpms ran a little rough, but I chalked that up to only rough tuning the carb/timing. After picking up my partner I motored the boat around at 1/4-1/3 throttle for at least half hour. I did open it up to 3/4-full throttle after a while, but only held it for a few moments. I was pleased with the power when the boat hopped out of the water, and the motor ran very smooth at higher rpms.

We went on motoring around the lake lake for an hour and a half, or so, when the motor seemed to have a fuel issue. The primer bulb was soft, so I pumped it until it was firm and it ran normally for a period of time (5min), then the same fuel issues started again. It only acted up on the higher rpm range when it would be pulling more fuel. I could let off the throttle and it would run better.

We headed back to the ramp and it became a struggle to keep it running. Seemed like it was running out of fuel. I checked the primer bulb and it was soft again. This time I pumped for a minute or two and it never got firm. The fuel gauge read over 1/2 tank the whole time. We limped it in the trailer and went home.

I pulled the fuel level sender and it appeared to be fine, and there appeared to be at least 1/2 tank remaining. The fuel lines look original, so I’ll probably replace them. Seems like there might be a blockage (it hasn’t been really ran in 7-8yrs). I’m also wondering if there could be a problem in the fuel line pick-up.

 

[jerryjerry05]

The squeezie's only job is to draw fuel from the tank to fill the system(bowls) with fuel.
Once the ball is firm? then it's job is done.
Once the motor starts, the ball is supposed to go soft.

The having to pump the ball to keep it running sounds more like a bad fuel pump
diaphragm or a bad fuel line connector??
If the diaphragm is bad, it allows excess fuel into the cyl. operating the pump.
That can kill the motor and make it hard to start and run.

The tank pickup, some came with a screen on the end??
But, I've never seen that style used by Bayliner.
If the tank has a lot of crud?? It could block the pickup??

First thing I'd check is the pumps diaphragm.
Replace the ball when you change the lines.
If there are inline connectors? don't replace them.

 

[Redbarron%%]

It could easily be a bad pump or an air leak, clogging in a filter or ?