force 125 issues

joshzimm

Cadet
Joined
May 6, 2010
Messages
11
HELP.....

I?m new to boating and new to outboard engines.
I bought a 1986 by-liner with a force 125 on it. When I bought it at the repair shop they were selling it because owner bought a larger boat from there lot. They hooked up muffs and started and ran forward and backwards with no problem.

2 days later after buying the boat, i take it out and it starts to run hard. dock it and looked it over and the timing nut is missing? ok get a new one and time it correct. Took it back out and it seems like it is surging at wide open. docked it again checked it over and checked crabs and compression spark ,T-stat, heat sensor but the water flow is in question, unable to find anything wrong took it out again. This time when at full out around 5k and running for about 10 min the engine comes to a screaming halt and it is dead ... cranked it over a few times and will only start it only will start with throttle half open... Dock it again... Check compression and (cylinder 2 is gone) -NOTE- I didn't know anything about outboard engines at this time but I?m a quick learn -- rebuilt the engine... cylinder 2 rings were smeared on the wall and didn't leave any cuts... the way that it burned looked to be high compression on a early flame front running lean ? Or overheating -> guessing <- honed the cylinder out and new piston and rings later... checked and cleaned all gaskets water cooling looked clean but still replaced the water pump while I was working on the motor.

Started the motor this year and i had to adjust the crabs and timing again and the choke but started right up... water comes out the exhaust pipe and only lightly spays out the (power port holes). Ran this in a tub for 30 min increments and no prob... Forward and back nothing out of idle worked fine.. took it out on the water and ran just fine, because I?m in brake in I?m running double oil and kept the rpm around 1k-3500 k ,, it ran fine for 30-40 min +/- but then when docking the boat would bog out when switching from forward to backwards. ??? Also when on plain there is no water coming out of the upper (power port) holes. Is that normal?


Question 1: what would cause the bogging after 30-40 of running?

Question 2: why when on plain would the water stop coming out of the power port holes

Question 3: when coming off plain the water is poring out of the power port holes is that normal

Question 4: is there any con's to installing a (tall-tail) out of the engine before t-stat


Question 5: is there anyone that could give me a detailed description on how the water flow operation works?

Thank you in advance for any help... and suggestions
Josh
 

pnwboat

Rear Admiral
Joined
Oct 8, 2007
Messages
4,251
Re: force 125 issues

Sounds like you are gaining some detailed experience with your Force motor! LOL. Anyways, on to your problem. I'll give it a shot here. If I make any mistakes or am unclear, I'm sure some of the more experienced folks can help.

Question 1: what would cause the bogging after 30-40 of running?
When running 25:1 I would expect the plugs to foul quicker than normal. Try cleaning them up with a wire brush and see if that helps.

Question 2: why when on plain would the water stop coming out of the power port holes This is normal. The two holes serve as a pressure relief for the exhaust and water. When at low speeds and idle, the exhaust spout is deep in the water. The exhaust pressure builds up as it doesn't have enough force to push it out the exhaust spout just under the cavitation plate when it's deep in the water. Once you get on plane, the exhaust spout is not as deep in the water and I suspect that there is somewhat of a suction effect which helps pull the exhaust and water out the exhaust spout.

Question 3: when coming off plain the water is poring out of the power port holes is that normal. This is normal as pressure in the exhaust cavity increases at low speeds and idle.

Question 4: is there any con's to installing a (tall-tail) out of the engine before t-stat. PROS - Lets you get a visual indication of water flow. CONS - Can't really think of any, other than don't make it too big.

Question 5: is there anyone that could give me a detailed description on how the water flow operation works? Water is pumped up the water tube to the adapter plate on the bottom of the block. It is then routed over to the bottom of the block to the bottom of the exhaust cover. There it runs up the water passages in the exhaust cover to the top of the block. It then runs down the left side of the water jacket around the cylinders to the bottom of the block. Then it runs up the right side of the water jacket around the cylinders to the thermostat. From the thermostat, it runs downward through the water passage in the cylinder head to the bottom of the engine where it is dumped out into the exhaust tube. Note: the water pressure relief valve in the diagram may not be applicable to your particular motor.
 

Attachments

  • water flow.JPG
    water flow.JPG
    113.2 KB · Views: 0

joshzimm

Cadet
Joined
May 6, 2010
Messages
11
Re: force 125 issues

THANK YOU FOR YOUR QUICK RESPONSE

As for the tall-tail I?m going to come off the engine at the top just before the T-stat there is an already drilled hole from the factory that has a screw to close it off. I?m going to pipe in and reduce down and mount a port on the side of the engine below the cover.

Thanks again for the information on the operation of the motor and cooling operation
 

joshzimm

Cadet
Joined
May 6, 2010
Messages
11
Re: force 125 issues

THANK YOU FOR YOUR QUICK RESPONSE

As for the tall-tail I?m going to come off the engine at the top just before the T-stat there is an already drilled hole from the factory that has a screw to close it off. I?m going to pipe in and reduce down and mount a port on the side of the engine below the cover.

Thanks again for the information on the operation of the motor and cooling operation


:cool::cool::cool:
 
Top