belts

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dway

Member
Joined
Oct 14, 2018
Messages
9
Location
United States
Vessel Name
WAYfarer
Vessel Make
Beneteau 44 Swift Trawler
I have a Beneteau 44' Swift Trawler with twin 300hp Volvo D4s
I notice that I get a fair amount of black powder from the drive belts
Is this normal? The belt tension all seem good. I did lose the starboard belt a week ago after seeing a continuous accumulation of black powder, there were no actual pieces of belt rubber, just the fine powder. I had both belts replaced but am again seeing black powder accumulating

thanks
 
Is there corrosion on the pulleys? Are the pulley's aligned properly? Are the bearings good? The dust is from friction. I would suspect the thrown belt and the dust are related.
 
The belts are slipping. Are you using OEM belts? My boat came with Carquest belts, and I had black powder all over the front of the engines. Switched to Cat OEM belts, no more powder.
 
Are you running your batteries down between the times the engine are running? The only thing with a variable load is the alternator and if it's working hard, it will cause belt wear.
 
belt slippage

I had the same problem with my old Trojan. It was gas not diesel but that has nothing to do with it. I had changed out the OEM alternator for a 150 Amp Powerline with an separate 4 stage voltage regulator. I used 4 golf cart batteries as a house bank and had a 2000W inverter and no genny I used it often and typically started with fairly discharged batteries in the morning. I bought the big alternator to recharge them while running. At first I heard a bit of squeal when running 1000 to 1500 rpm. I reasoned the belt was slipping under the load. I tightened the belt to a very tight condition. That was not a good thing for alternator bearing life. but the squeeling went away. I was getting a lot of black dust on the front of the engine, still. The belt looked glazed quickly after replacing it. The black dust was actually rubber from the belt. I put up with it for a couple short seasons, and two replacement belts. There is a difference in belt quality. But not enough to make a bad situation better. On the beginning of third season I adapted to a double belt drive. All problems went away. And, I didn't have to over tighten the belts any more. Problem Solved.
 
thanks for the tip
still not sure what is going on, I like the alternator working hard thought since we did have a period where our aux battery charger failed and the house batteries would get low. They would charge up when running the engines. I just don't like the thought of loosing a belt when out in the middle of nowhere on a 60 mile run. When we lost a belt last week we were only 4 miles from the reef and marina. Thanks for all replies, I'll keep an eye on it and when I get back to Florida have it looked at.
 
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