force 90hp seizing

[THOMASTHETANKENGINEBOB]

Hi can anybody tell me when my engine was trying to seize, number 2 was the worst, but number 1 was not scored at all

 

[HotTommy]

Thomas,
Had the engine run well and recently before the problem? Did you have the correct oil/gas mixture? Did the engine sit for a prolonged period before it siezed? Is there any reason to suspect a dirty carburetor may not have been providing all the fuel it should? Was the telltale spouting water as it should? How long since the impeller was changed? .... We need more than a few photos to diagnose the situation.

 

[tommarvin]

1. Overheating? Impeller, what temp does the stat open in warming hot water, around 150F
2, Not sure if a leaking head gasket would cause this.
3. Would you bet your life, there was 50-1 two stroke oil in the gas? This is classic the oil injector stopped, and this is what happens.
4.Did this happen on the water,or in the driveway on muffs? Always get the muffs where water goes in both sides of lower unit Did a plastic bag wrap around the LU.
5.Do you have a overheat buzzer or alarm, or temp gauge, water pressure gauge.
6.Tell us everything you can think of?

 

[jerryjerry05]

There is NO oil injection on any Force.
Damage like this wouldn't happen in the driveway.
The amount of carbon on the rings, rings seized on the piston, takes a while for this to happen.
A "leaking" head gasket would have water intrusion.
Thermostat is 130d
​The damage could be from: the carbs being out of adjustment, crud in the plenum, the recirc system being clogged, the fuel pump sucking air,
overheating, cheap oil, bad oil, and a whole bunch of other stuff happening.

Pull the thermo. and see if it's clogged/broken.
What are the air screws set at?
What year and model# pics of the block.
The early Forces were US Marine the later were Mercury.

 

[THOMASTHETANKENGINEBOB]

Thanks for the input, basically it started last year, went out to sea and drove for 500 yards and engine stopped, sounded like it had run out of fuel, eventually got it started again but the same thing happened again. Bought boat back to shore pulled the carbs off and discovered no fuel was getting into number 2 carb, float needle was stuck I then checked the compression and there was none on number 2 cylinder. In winter stripped engine down and got new Pistons, bearings and had it re bored, tried to get it going this weekend, set the timing and set the air mixture screws to one full turn out, it took a lot of turning over but eventually started. When pulling 2 or 3 spark plug leads off engine dies but when I pull number 1 off it doesn't make much difference, I checked the spark and it was ok and checked the carb was full of fuel just wondered if this is normal and seems to run ok. It's a 1991 force 90 hp L drive and I am mixing 25 to 1 to break the engine in. I am concerned that this could happen all over again, any help with setting the engine up would be appreciated, thanks for the help so far

 

[tommarvin]

1 The pictures were before when there was no fuel getting into the # 2 carb, and it burned up, then you rebuilt # 2 cylinder bore, and new piston.

2. Now your scared it's going to do it again, I get it now,I would take it to a shop and let them set the engine up,carbs timing,etc...

3. So no fuel in #2 cylinder means no lube in # 2 cylinder, means burned up cylinder, I just learned something. Another reason to keep the carbs clean.

 

[jerryjerry05]

Clean the carbs with Dawn soap and water.
​Blow dry.
Use no WD or ANY sprays.
When reassembling make sure the floats are set right.
Even with the casing when upside down.
Install a filter between the carb and the pump.
G2 or G3 or G12 Fram can be had at WM.
What's the compression on the new motor?

 

[THOMASTHETANKENGINEBOB]

hi my compression on all 3 cylinders is about 125/135 .cleaned carburettors out tried starting engine again started no problem but is only running on 2 cylinders. tested spark ok pulled plugs out or were wet with oil on them . so it seems compression spark fuel but only running no3 no 2 cylinders and not no 1 cylinder .so any more help would be appreciated