Serpentine belt

[wkskent]

I just bought a used 22i and the serpentine belt just frayed. I have a spare but am not sure what bolts need to be loosened to replace it. I do not see a tensioner pulley, do you have to release something else? it is a 2002 with the Mercruiser 350. Thx.

[R&T Babich]

Our Mag MPI does not have a spring loaded tensioner. The idler pulley above the raw water pump has a slot for tensioning. Use a 5/16" on the center pin and a 5/8" wrench on the nut. The small nut is used to tighten/loosen the belt tension and the larger one is used to cinch it down.

[chpthril]

Congrats and welcome to the site.

Sorry to hear about your mishap. May want to take a real close look at the other belt driven accessories, such as the Alternator, Raw water pump, Cooling circulation pump, to make sure one of them was not the cause of the fried belt

[wkskent]

Thanks for both the quick replies.

[TJRiver]

Make darn sure all of the belt driven accessories are aligned!! Voice of experience here......

[dogbert]

I just bought a used 22i and the serpentine belt just frayed. I have a spare but am not sure what bolts need to be loosened to replace it. I do not see a tensioner pulley, do you have to release something else? it is a 2002 with the Mercruiser 350. Thx.

I thought there was a service bulletin for '02 Mercruisers regarding the alignment of the pulleys that caused the belts to wear down prematurely. Anyone?

[Jason B]

I thought there was a service bulletin for '02 Mercruisers regarding the alignment of the pulleys that caused the belts to wear down prematurely. Anyone?

Never heard that. Mine is just hunkey-dorey. I check it pretty often though.

[dogbert]

Never heard that. Mine is just hunkey-dorey. I check it pretty often though.

Ok, I admit it, I was too lazy to look. Maybe we need a link for this permanently. Here's the Mercury Marine Service Bulletin.

[wkskent]

Alignment is a concern. My belt did not break, rather an edge of it was cut off all the way around, which suggests poor alignment? I have no idea how to align it all, is that a job for a mechanic or is it pretty easy to do?

[dogbert]

Alignment is a concern. My belt did not break, rather an edge of it was cut off all the way around, which suggests poor alignment? I have no idea how to align it all, is that a job for a mechanic or is it pretty easy to do?

Read the service bulletin.

[TJRiver]

dogbert, you are the man (......or dog?.....)

[samw]

That was some good info I will need to check that.

[wkskent]

great pointer in the right direction. I will report back what i find out when i look at this tonight.

[wkskent]

Well, even though the serial # of my engine is included in the service bulletin the alternator pulley lines up with the crankshaft so i am not sure the next step other than to try a new serpentine belt and see what happens. Possible the other belt was rotted because boat sat for two years (garaged) prior to my buying it.

[dogbert]

If it's never been replaced, it was probably due.