Smell burning rubber after take-off - alternator pulley gets hot quick

[mtcarrier]

I can't figure out what is happening here. I have been noticing a burnt rubber smell washing back in the cockpit after taking off from idle. This happened a couple of times where I looked dwon in the engine compartment to make sure nothing fell down in there - couldn't find anything and the smell would go away. This time, we had just taken off from the dock. After maybe 30s seconds we started smelling it. I noticed that the alternator belt and pulley were both really hot. I was afraid that the bearings were failing, so we packed it in. I pulled the alternator, and it spins freely - not making any noise. So, i'm not sure what the problem could be.<br /><br />Any suggestions?

 

[hondon]

Re: Smell burning rubber after take-off - alternator pulley gets hot quick

Take the alternator to the auto electric shop .Tell them the same story you have just told us and have them test and listen to it .If it is broken replace it with a marine ignition protected unit.

 

[galaxy]

Re: Smell burning rubber after take-off - alternator pulley gets hot quick

Are you sure your belt was tight enough? Sounds like the belt might be spinning on the alternator pulley when you throttle up and put a load on the engine.

 

[Dunaruna]

Re: Smell burning rubber after take-off - alternator pulley gets hot quick

Is there a rubber trail on your engine cover?Misalignment or a loose belt can cause the belt to disintegrate & smell.

 

[Trent]

Re: Smell burning rubber after take-off - alternator pulley gets hot quick

Since you did not say make, model and year Im guessing? Make sure you look at the rear of the engine also for "rubber dust". Coupler could be going bad? But you said the belts were hot? Make sure they are tight as was said above.

 

[port jeff boater]

Re: Smell burning rubber after take-off - alternator pulley gets hot quick

i have a similiar problem too.. but along with mine i get a squealing noise , then after about 2 to 3 minutes the nose goes away. i have a 140 mercruiser. i also noticed that the alt bracket has a small crack in it. this is the fifth time i replaced it in 2 years do they make this in stainless steel. please advise thanks

 

[mtcarrier]

Re: Smell burning rubber after take-off - alternator pulley gets hot quick

Thanks for the replies - I tightened up the belt and I'm taking it out for a spin tonight to test...<br /><br />I do have another question. Are alternators supposed to get pretty hot after idling for five minutes or so? Also, I am noticing that the voltage at the battery post starts swinging from about 14.0 to 14.8 volts if I increase the RPM above 1200. Is this normal? I'm doing this in my driveway, so I'm not sure if it's a valid test not having back-pressure on the engine. Will check again tonight. <br /><br />A little more info, I have a 1994 OMC 5.0l carb.<br /><br />thanks.