Engine struggles to turn over w/ lower unit on

[kabona]

Hi all.. I have a 1990 90hp force l-drive

I took my engine and lower unit off my boat to do some work.

Basically now...with my engine back in the boat...with the lower unit still not installed yet.. The engine fires up instantly, no troubles, almost too good.

But when I put my lower unit back on... The engine will struggle to turn over and I cannot start it.

I am pretty sure all the gear linkage is connected properly. Prop spins free when in nutural, so I can't see it being in gear somehow.

Any ideas?

 

[Frank Acampora]

Re: Engine struggles to turn over w/ lower unit on

The engine is always turning the pinion gear and thus the forward and reverse gears anytime it is turning over or running. THUS: If it starts with the lower unit off the problem is with the lower unit. Spinning the prop in neutral only spins the prop shaft and dog clutch. This only tells you that there is no binding of the prop shaft.

Try spinning the prop in each gear with the lower unit disconnected. If the only resistance you feel is the water pump, then the problem is in the alignment of the drive shaft. IF you have a lot of trouble spinning it with the water pump on, you may have excessive load on the impeller. IF you remove the water pump and the prop does not spin smoothly with little resistance, then the problem is in the gears. IF you removed the spool and reverse gear bearing carrier OR even the spool only and if you did not ensure the half circle clips were not in the groove of the case, it is possible that you are loading the reverse gear and it is binding with the pinion. If it is a Merc gearcase and you have the spool in incorrectly and the ring nut tightened, it is also possible to pre-load the reverse gear.

IF you did remove the reverse gear bearing carrier and did not grease the thrust washer (to hold it in place) it is quite possible that it is not seated in the recess and again, pre-loading the reverse gear.

 

[kabona]

Re: Engine struggles to turn over w/ lower unit on

Thanks for the quick response frank....... Very helpful.... Will update tomorrow after I rip the lower unit off again and check things out.

 

[kabona]

Re: Engine struggles to turn over w/ lower unit on

I took the gear case off again. Motor fires right up again.

Took the water pump off.

Driveshaft turns with a little resistance

Prop turns with some resistance in forward and reverse gear. A little more effort then i would have expected to spin..... but i am not a mechanic. Feels like everything is turning properly inside.

Does the little foam seal that goes around the driveshaft, go inside the pump housing or outside of it. I'm pretty sure the clear shows it on the outside of the housing.

Any precautions I should be taking that I could have missed when putting the gear are back on?

 

[Frank Acampora]

Re: Engine struggles to turn over w/ lower unit on

Here is where I can no longer help as I have never worked on an L-Drive. While some things are the same as outboards, others are not.