Belt slipping????

[Tige22ityper]

Ok, so I get my starting issue figured out then I go to take a set last night, fire the boat and hear a belt squeaking under the motor cover.........kill the motor and restart...same squeaking..........pull the motor cover up and the belt is not turning but seems to be slipping on the pulleys.........the crank is turning just fine, motor sounds normal but the belt it starting to smoke a bit from rubbing and not turning.........I checked the tension.....seems pretty tight........Did I have a pump go bad or possibly the impeller is shot?

Where should I start? I was thinking of re-tightening the serpentine belt, then starting to see what happens. Obviously if the belt turns fine, belt tension was a bit loose...........if the same problem, where do I look next? Water pump shot? Alternator?

Man this is lame...lol.........

Thanks in advance! You guys are all top notch!!!

[hoopykat]

Check to see that all contact points/pulleys with the belt are not stuck. As far as tension, you should be able to deflect the belt down with your thumb about half an inch or so and no more. Overtensioning the belt can damage the bearings of every contact pulley with the belt. It sounds like one of the pulleys is seized and the belt is skidding along on it, hence the burnt rubber and smoke. Look for black rubber dust deposits and you will probably find the frozen pulley.

-Mike

[Tige22ityper]

The belt didn't seem overly loose...had a small bit of play......I am really thnking its not too loose, but you never know. There is a fair amount of belt dust all over the front of the motor.........not sure which pulley it might be. I don't have time to go check it out right now, but will go down to the dock a bit later in the afternoon and bring my sockets, etc and see what I can diagnose........will check all the pulleys and alignments then see if any of them are stuck........if problem still persists, maybe it is the seawater pump and/or the impeller......

[jchurch6713]

I had a similar problem but the only pulley that was not turning was my seawater pump. I changed my impeller (was due anyway and always makes me feel better to change it at the beginning of the season) and I tightened the belt and so far no more problems.

[dogbert]

Do you have a Merc? If so, there's a service bulletin on the pulley alignment. Read this thread on the issue. Look for TeamAllen's post about halfway down.

[Tige22ityper]

I read the service bulletin..........it does make sense but I have never really had a problem with the belt shredding or whining........

I got an impeller from my mechanic today and pulled the boat off the water.......will attempt the impeller change right now, and also am going to buy a new serp. belt too.........might as well while I am at it.......hopefully the impeller DIY goes well...........it seems pretty straight-forward......move the fuel filter, un do the lines, remove the bolts and switch it out..........lol.....I say that now........will have parts everyhwere in about an hour!!

[chpthril]

may have been mentioned but, sorry, i'm too lazy to read all the post, but sounds like the impeller has flopped over and causing the belt to slip on the pulley.

[Tige22ityper]

Ok, now I am thoroughly po'd! It took about 5 minutes to take the pump off and get to the impeller.........it looked like new!!! WTF?? I wound up cutting my belt since I was going to replace it anyways so maybe it just might be as simple as a worn belt that wasn't tight enough?

Tried autozone to get one to match up so I could water start it, but they didn't have one to match so I will just run by my mechanics tomorrow and pick one up, install it, and see what happens...........all the pulleys spin freely.......not sure what else it could be it this doesn't do the trick.....

[chpthril]

The impeller may have looked perfectly brand new, but where the vanes flopped over the wrong way? Sorry you cut the belt.

[Tige22ityper]

No, the vanes were the right way........I double checked them........

[dogbert]

Ok, now I am thoroughly po'd! It took about 5 minutes to take the pump off and get to the impeller.........it looked like new!!! WTF?? I wound up cutting my belt since I was going to replace it anyways so maybe it just might be as simple as a worn belt that wasn't tight enough?

Tried autozone to get one to match up so I could water start it, but they didn't have one to match so I will just run by my mechanics tomorrow and pick one up, install it, and see what happens...........all the pulleys spin freely.......not sure what else it could be it this doesn't do the trick.....

BTW, one thing we discovered on a buddy's '02 was that Mercruiser had the wrong belt part number listed for his engine. We bought a belt from the dealer after his broke and tried to put it on. It had the exact same issues as yours. We finally had to take the old belt in to O'Reilly's and they matched one up. We did have to tighten it a couple of times for it to not squeal, but we finally got it going.

[formandfunction]

My major complaint with the merc would be the crappy pully setup.I too have had the same problems you are having.It turned out to be the groves on the contact side of the belt worn out.I would start by spinning all your pullys to make sure there not locked,then listen for bearing wear on the two upper idler pullys.If there not locked go to the parts store and match the belt (buy the high end brand).Another problem with this setup is the bracket to adjust the idler pully can get worn and your belt will lossen.
Good luck.