Advice for maintaining belt tension

[Shaneesprit]

Assume this is a Ribbed belt and not a Vee belt?
Ribbed belts you should just about be able to twist at 90’ any more it’s too loose.
Put a new quality belt, from a quality store, so you know it’s real - Gates are a good brand.
Remove and polish the pulleys especially those that run on the back of the belt.
If you have an upgraded Alternator is the belt capable of the load?

[HarryVandermeer]

I found that the OEM Yanmar belts last much longer. Do not stretch and significantly reduce belt dust.

[MJH]

Originally Posted by ramron67

I have a Yanmar 3YM30 on my sailboat.
Lately I find that I need to readjust the belt tension more frequently than in the past.

Any advice on what I should look for?

Is there any role for something like loctite to keep the adjustment bolts in place?

Thanks for any guidance.

Switch to a serpentine belt and you will eliminate all your problems. I did and have not had to adjust the belt since installed a few years ago. Balmar has some options to consider but there are others out there. Can be a job installing but depends on how tied you are doing what you are doing now.

Good Luck.

[Bluechart]

Caution: over tightening the belt can damage the water pump bearing.

After adjusting the belt to your engine specs, tighten the adjustment bolt AND the alternator pivot bolt. On my engine the deflection for a new belt is 6-8mm, used belt is 8-10mm.

I have marked the bracket with a line as a reference.

[Plumbean]

Originally Posted by MJH

Switch to a serpentine belt and you will eliminate all your problems. I did and have not had to adjust the belt since installed a few years ago. Balmar has some options to consider but there are others out there. Can be a job installing but depends on how tied you are doing what you are doing now.

Good Luck.

Agreed. I went with the Balmar conversion on my 3YM30. Pretty easy install and night and day difference -- no more belt dust.

[Cpt Mark]

Originally Posted by ramron67

Why do you recommend the Gates Green belts?

Think of the the Green belt as a radial steel belter tire vs just a bias ply tire. The green belt is built like a radial

[ramron67]

Originally Posted by Plumbean

Agreed. I went with the Balmar conversion on my 3YM30. Pretty easy install and night and day difference -- no more belt dust.

Thanks for this advice.
Can you post a photo of your set up?

[Cpt Mark]

Originally Posted by Plumbean

Agreed. I went with the Balmar conversion on my 3YM30. Pretty easy install and night and day difference -- no more belt dust.

just pricy

[Carl-T705]

If the pulleys are rusted from lack of use, all the rust has to be removed. Rust makes the belt wear and go out of tension. I would check that before investing in new belts only to have the same issue repeat itself

[AndyinAbudhabi]

I have the 4JH4 engine and had a similar problem. Fitted the Balmar alternator belt kit and haven't needed to adjust the belt for a couple of years. Not sure if they make a kit for your engine.

[Dave_R]

One thing I'm curious about...as a guitar player, I know that new strings stretch for a day or two before they stabilize.

New engine belts don't do that, do they? I've never heard of re-adjusting a new belt after the first few days.

I guess new belts don't stretch like new guitar strings.

[LeighWebber]

Another vote for the Balmar tensioner gadget. Worked well for me.

https://balmar.net/product/bbu/

[Plumbean]

Originally Posted by ramron67

Thanks for this advice.
Can you post a photo of your set up?

Don’t have one handy at the moment, sorry.

[Plumbean]

Originally Posted by Cpt Mark

just pricy

Yes, definitely pricy. I looked at it for a while before pulling the trigger. Happy I did, but may not be for everyone.

[Jentine]

I had that problem until I bought the belts from Yanmar……problem solved!