1990 90hp Force L-Drive won't start

[SSJMaestro]

Hello,

I will try to make this as clear as possible.
I have recently come across a 1990 90hp Force L-Drive.
When I originally tried to start the motor, the starter wouldn?t kick out. I manually engaged and lubricated the shaft.

I attempted to start the engine again. This time the starter engaged but turned the flywheel very slowly. I trouble shot the starter and everything seemed fine. I removed it and bench tested it and there were no issues. I took it apart and cleaned the brushes and reinstalled everything.

When I started it this time it cranked better but still felt slow. After further troubleshooting I removed the flywheel to find some internal components (shims) to be damaged. I replaced the flywheel.

I tried starting it again, the cranking was better but still it wouldn?t start. I removed the spark plugs (which were corroded) and found water in my 3rd cylinder. I removed the head, cleaned the cylinder walls, removed as much water as possible, lubed the cylinders, cleaned mating surfaces, reinstalled gasket and head cover, torqued accordingly and installed new spark plugs.

The engine now turns over very quickly but will still not start.

This is where I stand now, I would like to get any ideas that anyone can offer. I am open to all advice.

 

[contractorguy]

Re: 1990 90hp Force L-Drive won't start

With the plugs out, it should spin freely...although not 'really fast'.

Is the lower in neutral? Sounds kinda like bearings

Get it spinning, then do a compression test.

 

[SSJMaestro]

Re: 1990 90hp Force L-Drive won't start

ok, I pulled the plugs out and cranked the motor. Apparently there is still water going to the 3 cylinder. I thought I put it back together correctly, but I must have done something wrong. Can anyone verify the torque on the Head Cover bolts. Maybe I didn't torque them down enough or over torqued it.

But as far as the engine turning over freely, it does.

I am also unaware of how to properly do a compression test.

Please provide details if you can help.

Thanks

 

[Frank Acampora]

Re: 1990 90hp Force L-Drive won't start

Cylinder head bolts should be torqued to 225 inch pounds in three steps, in a spiral pattern working out from the center two bolts. The pattern is important to prevent distorting the head.

Double check the mating surfaces on both the head and block for nicks and be certain that the gasket is in perfect condition also--especially the metal compression sealing ring. Check the head against a piece of plate glass to be certain it is not warped. If it is warped more than 1-2 thou, you can sand down 10 thousands to true it up.

Remove the exhaust cover and check the gaskets. They are VERY thin right at the forward bottom (where the dog-leg is) and if they have not been installed properly, they kink and break there. This allows water to spray into #3 cylinder. Try not to destroy those gaskets when pulling the exhaust cover to check.--there are two of them, one on each side of the stainless plate, and they cost about 12 bucks each.

 

[SSJMaestro]

Re: 1990 90hp Force L-Drive won't start

I just came accross what might be another complication.
I removed the head again, I noticed there are some knicks around the area in the 3rd cylinder where the metal part of the gasket would make contact. The knicks aren't too big but do you think they can keep the metal ring from compresing properly and making a good seal.

Let me know.

 

[Frank Acampora]

Re: 1990 90hp Force L-Drive won't start

nicks in the sealing area of the head gasket will affect compression and may also tend to admit water.

Clymers says factory recommendation is to mill off no more than .010. HOWEVER: There is plenty of clearance and it is possible to remove as much as .060. Try to bolt on the head without the head gasket. You will see that the engine will turn over without the pistons hitting the head. This much metal removed WILL affect compression though and may make the engine require a higher octane fuel. Alternatively, see if you can find a used one. While the 90 had higher compression, any head from any three cylinder Chrysler or Force will work-Except possibly the three cylinder Force 70.

Heads don't usually go bad so they are not usually in demand. I would think a used head should go for 10-20 bucks--no more.

You can dress either the head, the block, or both if necessary. If you work on the block, be as accurate as possible and be certain to clean it well. It is much preferable to disassemble the block to do any work.

If you do decide to disassemble the block, consider porting the bypass and exhaust while it is apart.--it yeilds significant increases in power.

Think long and hard before you decide to invest any significant money in that boat. While the block is standard Force, the drive train--for lack of a better word --Sucks. The idea was good, the execution was poor. The package has a bad reputation, parts for anything other than the block are difficult to get, and there is no resale value because of the rep.