Are you kidding me?!... Mercruiser 165

[satrefftzs]

I'm running a twin Merc 165 setup, and I keep snapping belts on my port engine. The belt is EXACTLY the same as my Starboard belt, which is doing fine. Why??!! This is driving me crazy! Also, is there ANY other way to change the belt on these things without taking the front engine mount off, and lifting up the block...hence my frustration! Any help would be much appreciated.

[stonebreaker]

Is it a serpentine belt or a v-belt? In any case, check the alignment of your pulleys.

[satrefftzs]

To be honest with you, I don't know the difference between the serpentine or a v-belt. It's just connected around 3 pullies (water pump, altenator, other one?!). Is it possible to check/fix the alignment of these pullies without taking the engine out of the boat? I'm pretty much a one-man crew here! Thanks alot for your time.

[stonebreaker]

Well, a v-belt has a somewhat triangular cross section, while a serpentine belt is flat.



The second picture has a picture of a "v" ribbed belt. That type of belt is commonly referred to as a serpentine belt.

Here's a picture of a misalined belt. This is usually cause by a bent mounting bracket or maybe the wrong part number pulley or accessory.

[satrefftzs]

It's definitely a cogged V-belt. I'm going to tinker a bit this afternoon, checking the alignment of the pullies. I sincerely appreciate your help. I wish I would have known about this place sooner!

[Jango]

If you're snapping Belts, it sounds to me that one or more of your pulleys could be Excentric - not mounted on it's centerline, or posibly a worn shaft causing the center to change enabling the belt to tighten excessively. You might check this out by rotating the engine slowly, preferably by hand w. a wrench and checking tension at various points during one revolution.

Jango

[redtech]

just a thought on the belts if you have v-belts if the belt is to deep into the groove this can cause a belt to brake a v-belt runs on the sides not the bottom

[george allard]

Somebody probably rebuilt the alternator and left out the spacer behind the pulley. Also check the spacers, shims, on the mounting bolt.

[paraselene]

I had a 165 for many years, solid as a rock but a bear to change that belt. I supported the motor with a non leaking hydraulic jack into the bilge. After marking it's correct height, turned down the front engine mount adjustment enough to allow me to slip in two belts. Install one and zip tie the other out of the way as a spare. Turn the adjustable front mount back up, pull the jack and I was done. Be very careful jacking into the bilge, distribute the load and watch the front of the engine for lift (try not to lift at all). As to belts, there are A and B types (sizes), as long the bottom of the belt is not touching the base of the pulley alignment looks like the problem as previously noted.

[jparler]

you can remove the belt without removing the mount. the right side has 2 bolts on the block when you remove them a piece of the bracket will slide out