1989 125 hp L drive problem

[dhargrover]

I'm having trouble starting my engine. It acts as if the battery does not have enough power to crank the engine, but if I remove the spark plug from the bottom cylinder, the engine turns over just fine and will even start and stay running without that spark plug being in there. There is also tons of I assume fuel, more than normal that discharges out the spark plug hole while it is running. Sometimes I can manage to get it started with the spark plug installed in the bottom cylinder. This allows me to test the ignition of the lower cylinder. I can feel the spark in my arm when I touch the cable, also the engine doesn't feel like it is missing any when I disconnect the spark plug cable. I've swapped spark plugs and it's always the same. It doesn't appear that the spark is firing inside the cylinder, but there is spark on that wire. I'm no mechanic, but the best way I can describe it is that it seems what is happening is that somewhere a large amount of fuel or fuel and water is getting into the lower cylinder and somehow not allowing the fuel to ignite in that cylinder. The large amount of fuel in that cylinder also seems to be really locking up the engine when it is trying to start, almost as if it is completely full of fuel and because of the compression on either side of the piston, it doesn't move at all.
Something else that happens is that after the engine is running for a while, the fuel line develops a vaccuum and essentially collapses so that there is no longer any fuel getting to the engine. The two may not be related.
Thanks in advance for any advice.

 

[roscoe]

Re: 1989 125 hp L drive problem

Welcome to iboats.

You need to determine if the fluid in the bottom cylinder is fuel, or water.
If it is fuel, the engine is flooding, likely from a worn out fuel pump that is leaking from the back side - into the crankcase and ending up in the bottom cylinder.

If it is water, you ned to determine how it is getting from the cooling system, into the cylinder.

You also need to check the spark strength. The spark needs to be a bright blue spark, that will jump a 7/16" gap. A $7 spark tester will help to test this.
From what you wrote, I suspect you have very little and/or intermittent spark.

As for the starter not being able to spin the motor; could be a weak battery, a loose or corroded connection, or an old dirty or worn out starter.

Fuel line "vacuum" problem. There is an obstruction in the fuel line, between the fuel tank and the fuel pump.
It may be in the fuel pick-up tube in the tank, in the line or primer bulb, or in the tank vent that allows air in, to replace the fuel being pumped out.

What you really need, is a manual (Clymer's) to help you understand the motor systems, and diagnostic test procedures, so we can help you with the repairs.

If you want to get familiar with your L-drive, use the search function and read what problems other members have had.

 

[steelespike]

Re: 1989 125 hp L drive problem

Be sure to do that Ldrive search.Even the Force fans stay away from the Ldrive.While some are successful there appears to be many problems.

 

[sari]

Re: 1989 125 hp L drive problem

check your startor motor

 

[newbie4life]

Re: 1989 125 hp L drive problem

Be sure to do that Ldrive search.Even the Force fans stay away from the Ldrive.While some are successful there appears to be many problems.

Not that the L-drive has anything to do with this current problem. This is an engine issue, not a drive issue. Remember that the L-drive is still just a regular force powerhead on a proprietary lower unit.... which many parts are interchangable with most of the other lower units from a force engine.

 

[Nate3172]

Re: 1989 125 hp L drive problem

I would bet that the slow to turn over issue is related to the fact that there is too much fuel in the cylinder that is overfilling. It is probably hydraulicing the piston and can cause substantial damage to the engine if you continue trying to start and run it with it being like this. It can bend the rod or even break the piston and rings. Remove your fuel line where it comes in from the tank to the fuel pump, remove your spark plugs and turn the engine over until the cylinders are no longer pushing any fuel out of the spark plug holes. Let it sit for a couple hours to let any remaining fuel in the cylinders to evaporate. Replace your spark plugs but leave the fuel line disconnected. Turn the engine over and you should be able to determine if the engine can turn over freely without all the fuel being pumped into it. If it does turn over ok, than start checking out your fuel system. I would check the fuel pump diaphram first and then move on to the carburetors and look for a sinking float or a bad seal on the float needle that would be allowing fuel to overfill the cylinder.

 

[dhargrover]

Re: 1989 125 hp L drive problem

Thanks for all the help.

I think I found the problem. The diaphram is cracked on the side where the fuel comes in from the tank. The backside of the diaphram has a tube which leads right into where the lower cylinder is. I will know more once I replace the diaphram.

 

[dhargrover]

Re: 1989 125 hp L drive problem

Yes!

Replacing the cracked diaphram solved every problem I was having. The engine turns over easily, starts easily, no problem with the spark, and the fuel line no longer collapses.

Thanks.

 

[roscoe]

Re: 1989 125 hp L drive problem

Wonderful.

Happy boating.