1980 Chrysler 6 horse - no power

[twocyclemania]

Went out today for the first time with my 14' Lowe Sea Nymph (the lighter 14' Lowe) using my 1980 Chrysler 6 horse. It seemed to have very little power. I've used a 7.5 Johnson on the boat before and it planes easily. I also have a 3 Evinrude mounted to the side and the Chrysler 6 doesn't have anywhere near twice the horsepower that you'd expect. This motor is pristine. I don't believe it was used more than a few times.

I checked the plugs and both were firing nice and clean. The motor responded to throttle and idled nicely. The throttle linkage indicates that it's running to the (stop) maximum. I tried the one carburetor adjustment and it didn't matter which way I turned it. I ran it for a couple hours with no problems but it had little power. Am I expecting too much from a Chrysler? Is there something I've missed? Or is this normal for a Chrysler?

The motor has a new impeller and actually runs cooler than most of my other motors. I've replaced one of the coils with an OMC and it has new condensers. Once again, the plugs were firing clean.

I did notice that it has a black plastic prop. Is this factory and could it possibly be the problem? I also noticed that it appeared the rpms picked up when I ran it dry which is usual for motors but it did seem to indicate that it can run at higher rpms. Any ideas? thanks!

 

[twocyclemania]

Re: 1980 Chrysler 6 horse - no power

I see there's no suggestions so I went over the motor again. I pulled the prop this time (it has to be the original and in nice shape) and found a small ball of monafiliment with some vegetation wrapped around the shaft behind the prop. Not a major amount like when you pick up seaweed or eel grass.; I know this can slow a motor up. All in all the ball I picked off would be a little less than the size of a golf ball. Anybody think this could be the problem as I didn't find anything beyond my original post?