Force 120 Outboard

[pdltfc]

After being started it sounds good for several minutes then sounds like it might need carburetor adjusting.
Carburetors were readjusted and still had the same problem. Further checking confirmed that cylinders were getting spark but after checking the spark plugs in cylinder 1 and 2 there was no trace of fuel on the plugs. It appeared that the fuel had been steamed away. Fuel deposits were present on cylinders 3 & 4.
I guess that would probably indicate that the head gasket was leaking between cylinders 1 & 2. Problem is that when checking compression all cylinders were 147 to 150 lbs. Question. Could this still be a head gasket even though there is no loss of compression. What else should I be looking at. I'm not sure where to start. Thanks Paul

 

[Frank Acampora]

Re: Force 120 Outboard

If I read correctly, the top two plugs are clean, but the cylinders are getting fuel and firing.

If this is correct, yes, it could still be a head gasket, but it is more likely that the exhaust cover gasket is leaking, squirting water into the exhaust ports, steam cleaning the plugs.

 

[MostlyHrmlss]

Re: Force 120 Outboard

Just pulling this out of my back pocket, but have you tried a compression test when it's hot? Have you checked the head bolts for proper torque? Maybe the head is warping under heat and load, just enough to create a minor water leak.

 

[pdltfc]

Re: Force 120 Outboard

Thank you for your replies. I know that I am getting spark to plugs 1 & 2 because I had them out when checking for spark in these 2 cylinder. As far as fuel I don't know for sure. I do know when the motor is running it makes no difference if plug wires 1 & 2 are connected or not the the motor sounds the same as it is running on only 2 cylinders.
I have not yet tried a compression test with the engine hot.
Admiral Do you feel that I should start with the exhaust cover?

Paul

 

[Frank Acampora]

Re: Force 120 Outboard

NO! My opinion has changed with the additional information.

Since there is a good chance that at least one bolt on the cover will snap and the gaskets always are destroyed in removing them, I would start by checking fuel delivery.

Since you say that it always seems to be running on two cylinders and pulling the plug wires off the top two causes no change in performance, it is logical to think that they are not getting fuel--that is why they are clean.

So, the top carb and the line from the bottom one need to be removed and cleaned. Be thorough and fussy. See my recent post on diagnosing online.

 

[pdltfc]

Re: Force 120 Outboard

Frank, If I misled you to think I wasn't getting fuel to the top carburetor I was wrong on how I said it. I believe I am getting fuel to the top carburetor because before I cleaned the needle and seat and readjusted the float it was flooding.
Thanks Paul

 

[MostlyHrmlss]

Re: Force 120 Outboard

I'm with Frank on this one...you need compression, fuel, and correctly timed spark in order to get fire. You say you have compression and spark, so either there's no fuel to burn or the spark is coming at the wrong time, as if the wires for 1&2 were crossed. Static time it and see if #1 fires near TDC.

 

[pdltfc]

Re: Force 120 Outboard

I will check the static timing next. I know I'm getting fuel to the carburetor but its dosen't seem to be making its way into cylinders 1 & 2. Thanks again

 

[Frank Acampora]

Re: Force 120 Outboard

Wait--Wait--Wait-- My head is hurting! I'm now officially confused.

As soon as the engine starts, does the problem with the top two cylinders appear or does it take time? If the engine starts well and runs well for a couple of minutes, then we can assume it is not a fuel problem. If the problem is immediate, remove the plugs and squirt fuel into the cylinders. Now try it. try squirting fuel into the carb to keep it running. We are trying to confirm that yes, it is getting fuel, or no, it is not. Just because you cleaned and reset the carb does not necessarily men it is delivering fuel correctly--mind you, it is not that I don't trust YOU, I don't trust anyone. LOL Go back and look at my post on diagnosing online.

You already have checked spark, so then we are back to water intrusion. Again, because the exhaust cover bolts are likely to give you trouble, I would first pull the head and look into the cylinders. If the head and combustion chambers look steam cleaned, and/or If the cylinder liners show mild rust after sitting a day or two, then yes, water is confirmed and if the head gasket appears OK, then yes, it is time to check the exhaust cover gaskets.

 

[pdltfc]

Re: Force 120 Outboard

Frank I removed the head and found that the gasket looked good. # 1 and #2 cylinder wall after 2 days showed a minute trace of rust in a very small area. I tried removing a few bolts from the exhaust plate and the first one I tried snapped as you predicated. Is there any thing special like heat that can be used to make these easier to come out? Whats my next move any suggestions. Thanks Paul

 

[Frank Acampora]

Re: Force 120 Outboard

Try soaking them for a couple of days with penetrant--I know, useless, but can't hurt. Also try wiggling out the bolts --back and fort about 1/8 turn then increase sometimes that works. After the cover is off, you will need to drill and retap the broken bolts: Replace the cover snugly with all the unbroken bolts. NOW, in each broken bolt hole (assuming the bolt broke flush with the block) tap in a 5/15 roll pin as a guide. Use a cobalt steel 3/16 drill bit to drill out the broken bolt, then drill deeper into the block, BUT carefully. Aluminum galls and you will snap the bit. Use plenty of oil and drill about 1/16 to 1/8 inch at a time. Re tap 1/4 X 20 and use longer bolts.

For those bolts that broke about 1/4 inch above the block: Soak with penetrant for several days. heat the block with a propane torch. Grab with a Vice Grip as tight as you can manage--BTW: the original brand, not a cheap knock off--and try wiggling out.

 

[sidenberg]

Re: Force 120 Outboard

If I may put my 2 cents in. I suspect a fuel delivery problem. I had a similar issue so I did a carb clean. Problem was I used carb cleaner everywhere that destroyed the rubber part of the needle and seat causing the needle to get stuck in the seat. After removing the carb a second time and replacing the seat the motor ran great.

 

[pdltfc]

Re: Force 120 Outboard

I'm still with it but not having much luck. I put penetrating oil on the exhaust bolts every other day for 2 weeks heating them with a propane torch and so far out of 5 bolts I haven't been able to remove one with out have it break off. I guess my question now is taken the lower cowl off to access the 2 lower bolts so that when they snap I can get to them with a drill or vice grips. Any other suggestions. Thanks Paul