force 50 possible spun prop?

[prcuffel]

The top speed is about 5mph. Everyone tells me it is a spun prop. It appears the prop is one solid piece with spline and pin attachment to shaft. Is there any other protection devices ie:shear pins, clutches? It's about an '85 motor. Where can I get a new prop? The boat it is pushing is an old heavy wooden 17' cuddy cabin. It was previously powered by a 45hp with no trouble.How can I tell for sure it's a spun prop?

 

[roscoe]

Re: force 50 possible spun prop?

If you take the prop off, you can scribe or paint a line from the inner most part of the hub, outward to the outside edge of the housing. Then you can test run it, doing several holeshots. Then remove the prop again and see if the line is still lined up, or if it has been broken. <br /><br />If it is spun, it can be repaired (rehubbed) for about $40. <br /><br />Replacement props are kind of hard to find for your engine. Perhaps a dealer will have some laying around, or you can watch ebay. But buyer beware on ebay, you may be buying a prop that needs to be rehubbed.<br /><br />You have a pin drive, which is not a shear pin. It is there to protect the shaft splines. <br />The "clutch" is the rubber hub, inside of your prop.

 

[prcuffel]

Re: force 50 possible spun prop?

Thanks for the help,Roscoe.

 

[roscoe]

Re: force 50 possible spun prop?

Let us know how you make you, or if you need further help.

 

[prcuffel]

Re: force 50 possible spun prop?

I had the prop rehubbed without testing it because of a flat on the trailer and it only cost $23.84.I'm still having the same problems.The boat does well through the first quarter of the RPM range and then starts slipping.The guy at the shop said it could be a problem with the lower unit and it wasn't worth fixing. The motor runs wonderfully,always starts.I just need to get that power to the water.I did test the prop today, no slippage.

 

[help_ma_boab]

Re: force 50 possible spun prop?

Good Boy, if your prop is OK, and you are experiencing 'slip' above quarter throttle, could it just be the motor suffering from cavitation, you know - sucking air and bubbles to the prop instead of water to bite on? You mentioned a previous 45hp motor was ok on this boat - you have'nt replaced a long shaft 45 with a standard shaft 50? Is the motor trimmed down fully? These questions are kinda obvious, so some of the experts on this forum will assume you have already considered them - but if you are anything like me - start at the bottom and work up - you might have missed one.<br />Hope its of some help....<br />Bill

 

[prcuffel]

Re: force 50 possible spun prop?

I looked at the exhaust on the boat and it appears that a peice is missing.It is a two part cover for the exhaust.The front piece is gone and the back piece is loose.Could this be causing my troubles?The exhaust is now coming out in front of the prop instead of towards the rear like it is supposed to.It doesn't appear to be sucking air from the surface.Where could I find this piece? I need to find this piece so I can take it out and adjust the trim to try that.Thanks for all your help.

 

[prcuffel]

Re: force 50 possible spun prop?

I looked at the exhaust on the boat and it appears that a peice is missing.It is a two part cover for the exhaust.The front piece is gone and the back piece is loose.Could this be causing my troubles?The exhaust is now coming out in front of the prop instead of towards the rear like it is supposed to.It doesn't appear to be sucking air from the surface.Where could I find this piece? I need to find this piece so I can take it out and adjust the trim to try that.Thanks for all your help.

 

[catfish1]

Re: force 50 possible spun prop?

seems to me the force 50's have alot of lower unit problems, hmb has some good ideas about it.<br />ps. if you lived closer to west virginia i could hook you up with a lower unit, i know a guy that has a couple he'd probably sell for $50-$75.

 

[prcuffel]

Re: force 50 possible spun prop?

I was looking at the lower unit to find an oil leak. I found that part of the exhaust was missing.It appears that this is a two part "cover". The front piece is gone and the rear part is loose.This would put the exhaust in front of the prop instead of behind it. Would this be enough to cause cavitation. The previous motor was a short shaft.Does anyone know where I could find the exhaust piece?Also the lower unit is leaking oil.Where can I get the gaskets for it?Any information would be appreciated.

 

[nadawes]

Re: force 50 possible spun prop?

Almost assuredly your problem is going to be a bad forward gear. They had a bunch of bad ones as I previously posted to another question recently. I have a good 30 years playing with these old motors and still lots of parts sitting in boxes just waiting.