1987 force 50hp wot running problems

[John5421]

My engine seems to idle fine and run fine at low speeds but when I start opening it up. I get a stuttering feel (slight jerk) like it slips when running at higher speeds. It does it about every minute or so when running wot. And then at wot it revs real high like it popped out. I've had a spun prop about 2 months ago; replaced the prop, and it ran fine for about month and now its doing this could it be a spun prop again. Or its starting to be spun never did this too the old prop when it spun.

 

[roscoe]

Re: 1987 force 50hp wot running problems

Most likely a worn clutchdog, a large cog type gear that engages the forward or reverse gear.<br /><br />Not sure about your motor, but you may be able to turn the clutchdog around, or have it resurfaced at a machine shop. Or you can replace it.<br /><br />The more you run it in its current condition, the worse it will get, and possibly break it, leaving you stranded. It also puts a lot of stress on the motor.

 

[John5421]

Re: 1987 force 50hp wot running problems

roscoe where is the clutchdog located and how easy is it to take out and replace. And is it an expensive part. I tired of putting more money in this motor.

 

[eurolarva]

Re: 1987 force 50hp wot running problems

Here is a link for a 50 HP force lower unit. The part you need is item 24 however mercury is not showing a price for that item. You can call any mercury dealer with this part number and see if they still sell it. A word of caution is that when the clutch dog goes out your forward gear usually is bad as well. If you do this yourself you will need a service manual and a seal kit for this unit. Also post your model number because there are a bunch of differnt force 50 HP motors for that year.<br /> lower unit

 

[12Footer]

Re: 1987 force 50hp wot running problems

By all means, inspect the hub again.The prop hub could certainly have spun out again. This motor/prop/lower unit setup is notoriously hard on prop hubs. Hole shots with the Force 50HP are strictly out of the question because of this. You can't use it for pulling out skiers , that's for sure. The skipper of a pre-1992 Force 50HP should allways carry a spare prop for such situations.<br />The hub will hold forever if you nurse the throttle up thru the power band. They just can't handle hole shots at all.<br /><br /><br />IOW, been there, done that , got props all over the place (garage, boat bilge, truck box,ect)

 

[John5421]

Re: 1987 force 50hp wot running problems

What size of prop and pitch do I need when i go to buy a new one. The model number on my motor eurolarva is 507x7c. How much on an average does the prop on this motor run. The motor came with an extra one but maybe that ended up spun too. Thanks everyone for their advice.

 

[12Footer]

Re: 1987 force 50hp wot running problems

11.5" dia X 15 pitch. This prop is the only pitch/dia available, unless you have one custom made. Under most conditions, tho, the standard prop is fine. Check with the prop shop where you got the original re-hubbed for a spare. Ebay usually has a guy selling a used one.You might try iboats' "Marine Megamall" for a new one.

 

[eurolarva]

Re: 1987 force 50hp wot running problems

Here is the correct link to the lower unit for the model you posted.<br /> lower unit <br /><br />Draw a line on the prop to the prop nut with a magic marker to see if hub is spun. I hope that is the case because taking lower unit apart is a pain.