1993 OMC 5.8 Alternator Witchcraft

[raquettelaker2]

Alright, boat is a 1993 Four Winns H210, with ~760 hours on it. A few weeks ago I put a new SS prop on it and took it out for some hole shots and top speed runs. Get down to the end of the lake and slow down to turn around and am assaulted by a burning rubber smell. Get back to the dock and see the alternator belt all glazed up and shiny, burning hot to the touch. This is July 3rd, beginning of our vacation week, so I overnighted an alternator from West Marine, which arrived July 5th. I installed it myself with really no issues; dash gauge lit up around 14v, hooray!

Couple days later, out horsing around in the boat, and the burning smell is back. Sure enough, brand new belt is all glazed up and burning hot, belt dust all over. Dash gauge was reading about 12v while cruising around 2500 rpm. Meanwhile, the powersteering v-belt, which shares the crank and waterpump pulleys, is cool to the touch. What is going on??

Old alternator was a 3-wire Prestolite, original to the boat, with orange, black, and purple excite wire.

The new alternator is a Sierra, purchased from West Marine. Didn't take a pic but it looks just like the one I uploaded. I've been reading something about adding a jumper wire between sense and B+? Any validation to this? Why wouldn't the original alternator have had that?

Our pulleys are a little rusty but I kind of think there's more going on here. Might also be worth noting since this issue has arisen, the boat is a complete DOG; it can't get out of its own way. It'll get up to top speed of about 49-50mph, but getting on plane takes a recklessly long time. (Could also be that the entire ignition system is original to boat too; just ordered all new wires, plugs, cap, rotor, coil to put in soon).

Any insights would be much appreciated!! Thank you in advance.

 

[kenny nunez]

The rusted pulleys are your problem. They will keep eating up the belt. So you either have to keep changing belts or get a new set of pulleys. The belt dust has clogged the flame arrestor. Remove it and try to blow it out from the inside out. Then wash it with soap and water . Since the alternator is a different style does it have the same wire connections or is it a 1 wire type that self energizeses.

 

[raquettelaker2]

The rusted pulleys are your problem. They will keep eating up the belt. So you either have to keep changing belts or get a new set of pulleys. The belt dust has clogged the flame arrestor. Remove it and try to blow it out from the inside out. Then wash it with soap and water . Since the alternator is a different style does it have the same wire connections or is it a 1 wire type that self energizeses.

Thanks, the flame arrestor was supremely dirty and I did give it a thorough cleaning with degreaser, water, compressed air. Was expecting a huge surge of power back, but not really.

As far as I know the new alternator is not a self-energizer. It has an excite terminal on the back of it. I'm having my mechanic shine up the pulleys next week and will see if that helps.

 

[alldodge]

Don't see rusty pulleys as being an issue, while they may cause some extra wear that won't be very much. Take the belt off the ALT and power steering pump, then spin and turn each one and see if anything is dragging like the water pump or PS pump

 

[raquettelaker2]

No Title

Don't see rusty pulleys as being an issue, while they may cause some extra wear that won't be very much. Take the belt off the ALT and power steering pump, then spin and turn each one and see if anything is dragging like the water pump or PS pump

Thanks for the reply. The PS pump is on a separate belt, but shares pulleys with the crankshaft and water pump. I don't think there's anything resisting within the PS or waterpump, as that belt stays nice and cool to the touch. It's just the alternator belt that's cooking.

 

[alldodge]

Yes, I understand, I want you to take all the belts off so you can turn the water pump. Then after checking the water pump you could also check the PS pump just for fun since nothing will be on it

 

[Jammer864]

Run it with the alternator belt off and see if performance picks up. Do it quick though, you are on battery power only!

 

[Jammer864]

Their may be a big load on the alternator if the battery is failing and taking a large charge. Maybe the battery is starting to short internally. Try a different battery and see if the load is eased on the alternator.

 

[raquettelaker2]

Thanks, guys. I took the alternator out again and put a jump wire between B+ and sense. Also replaced the battery which had a manufacture date of 2010, so I'm sure it was well due. All is well in the world again!

 

[Yoni]

Thanks, guys. I took the alternator out again and put a jump wire between B+ and sense. Also replaced the battery which had a manufacture date of 2010, so I'm sure it was well due. All is well in the world again!

HI
Have exactly the same problem
How did you fix it?
Tnx

 

[GA_Boater]

HI
Have exactly the same problem
How did you fix it?
Tnx

He fixed it by starting a new thread instead of reopening a 3 year old thread.

Closed.