2000 Mercury Optimax Tensioner installation questions

[bassfisher89]

2000 Mercury Optimax 200 hp. #0T166101.
Fishing a tourney last Tuesday the boat came off plane and died. Found the belt ripped to shreds and the tensioner bolt had backed completely out. Trolled back to the ramp as I know better than to try and run it 😂. Ordered new tensioner assembly spring obviously a belt.

installed the above items all OEM Mercury and it still doesn’t appear to have near enough tension on the belt. I kind of feel like I am not holding my mouth right or installing it wrong. When you go to install what process do you follow? Hoping don, Joe, or savage might chime in. I almost feel like I have the spring oriented the wrong way or maybe I somehow got a bad spring. I’ve greased it really well, put a spacer between the bushing and block etc. I plan to use Loctite when I figure out why it’s not applying enough tension. Nothing seems to be out of place or another outlier. I think I recall removing the alternator last time when I installed the tensioner but I don’t think that should have to be done.

I have the factory manual it really doesn’t give me much info as far as a procedure. I’ll add I’ve checked the compressor, alternator, Belt depth, I’ve also done the inch pound test on the idler. And I will be cleaning the air plentum and change plugs this weekend before I ever fire it back up. Appreciate the help! Y’all really helped me on the rebuild a great deal!

[EuropeanAM]

The tang on the block is a bit further away than you might think. Look for the wear mark where the spring tang has been contacting... you will need to rotate the spring and tensioner after it's engaged that slot and push DOWN at the same time, taking care to rotate far enough that the tensioner can come down fully.

Using your left big toe, hold everything together while you fumble for the washer, nut, socket and ratchet, assemble those being careful not to slip and hit yourself in the mouth.

I know- poor attempt at humor, but once you've done it successfully, you'll understand that the above has an uncanny amount of truth to it.

[bassfisher89]

Just to make sure It is in the right position I am going to attach a picture with the location of the tang. It’s still not tight enough. I feel as if the spring is bad or I have a belt that’s been stretched or something. Or maybe the tang is in the wrong location. When I do what you said above it feels like it is installing correctly because it kind of snaps in. And yep gotta do all the above to get it just right �� 7607191A-E615-484F-927E-E0446DB0A03D.jpeg

[EuropeanAM]

Belt is probably stretched- about the max I would run one on that series is 4 years or 400 hours (whichever came first).

Put a lbs/in (Inch Pound) torque wrench on the tensioner, set to 70 lbs/in. It should click before the tensioner reaches it's mechanical limit.

[bassfisher89]

The belt is brand new. It’s a merc quiksilver belt. The tensioner actually passes the inch lb test after about a half inch of turn

[bassfisher89]

I know the pain you are going through with the tensioner mess ��! You can click the link in the announcements section of the forum. It will take you to European Marines parts page. I think you will have to make an account. Then it takes you to a screen to enter your mode number. From there all the parts/numbers you need will be under the alternator diagram. I don’t think a kit is available but you shouldn’t need the arm itself I wouldn’t think or the idler pulley if it spins freely. Probably just a bushing and a spring if it everything else looks good. Don can probably give you more accurate advice than I can.

[EuropeanAM]

There is no "kit"- you would need to order/replace any damaged, worn or deteriorated components.

[btribby]

I know the pain you are going through with the tensioner mess ��! You can click the link in the announcements section of the forum. It will take you to European Marines parts page. I think you will have to make an account. Then it takes you to a screen to enter your mode number. From there all the parts/numbers you need will be under the alternator diagram. I don’t think a kit is available but you shouldn’t need the arm itself I wouldn’t think or the idler pulley if it spins freely. Probably just a bushing and a spring if it everything else looks good. Don can probably give you more accurate advice than I can.

Thanks for the info. I appreciate it. For some reason the parts website hasn’t worked all weekend for me. Which is why I was asking about part numbers. I was able to find the part numbers on other sites. I plan to call European Marine in the morning.

[bassfisher89]

Still fooling with the tensioner. I still feel like I don’t have enough tension. When it’s properly torqued it’s pretty tight and doesn’t spring back like it should. Does pass the 70 inch pound test but it’s close to the end of the swing of the tensioner. Should I buy a new spring just to see? Belt is new, new tensioner pulley is new, I guess the spring would be the only likely problem left ??? Scratching my head on this one sometimes the simplest things are the most aggravating.

[bassfisher89]

Still fooling with the tensioner. I still feel like I don’t have enough tension. When it’s properly torqued it’s pretty tight and doesn’t spring back like it should. Does pass the 70 inch pound test but it’s close to the end of the swing of the tensioner. Should I buy a new spring just to see? Belt is new, new tensioner pulley is new, I guess the spring would be the only likely problem left ??? Scratching my head on this one sometimes the simplest things are the most aggravating.

[SilverFox579]

The tensioner spring generates the belt tension, if you haven't replaced it, that could well be the issue.

[Savage]

The tensioner spring generates the belt tension, if you haven't replaced it, that could well be the issue.

This

[bassfisher89]

Alright I’ve replaced the spring didn’t seem to make a big difference. Put the motor on muffs. Compressor only rotates every so often while idling and the motor will die sometimes. but under load everything rotated fine and sounds fine. Something squeaks at idle I can’t tell what it is. I would assume the compressor should turn all the time whether with or without load. Am I wrong?

[bassfisher89]

It does build up enough pressure when rotating by hand to make it harder to turn. But it is the original compressor the ones that failed often. I believe the new belt has tightened up with the new spring. Everything else turns fine when idling except the compressor it turns but is intermittent. Occasional squeal from belt or compressor would be my guess. Under load everything turns great no squealing etc. I can turn everything by hand via the flywheel nut and a ratchet everything turns that way as well.

[SilverFox579]

The compressor should ALWAYS turn when the engine is running...

[EuropeanAM]

Remove belt.

See if you can turn the compressor pulley CLOCKWISE with ONE HAND beyond three (3) complete revolutions. This should be quite difficult to accomplish. If not, there's either an air leak, or the compressor is failing.

Check the tensioner with a torque wrench (lbs/in or INCH POUNDS) set to 70 lbs/in. Should click BEFORE you reach the end of it's travel. If not: Spring is bad, or tensioner is improperly installed.

[bassfisher89]

Removed belt, tensioner clicks quickly in the swing of the arm at 70 inch pounds, compressor does have quite a bit of resistance while turning. I’ve taken some videos I’m going to try to figure out a way to share them. One of me turning the compressor, doing the torque wrench tensioner test, spinning the alternator ( seems like it should spin smoother), and the tension wheel. I’ve also taken some more pictures of where the belt is riding, location of the spring under the tensioner. How far it’s compressed etc. My concerns at the moment 1. I don’t think the alternator turns as freely as it should. Should it have much resistance? 2. Maybe somehow I’ve messed that brand new belt up. 3. Would it be worthwhile or is it possible to install the new style tensioner with the grease fitting and stud /locknut setup. I just feel I’d have less of a chance of it backing out. I’ve cleaned everything out since the belt shredded fortunately I didn’t have any residual belt Debris in the reeds or the compressor. I’m going to try to upload some pictures and videos but I may have to use my laptop to do it. Again I really appreciate you guys for the help.

[EuropeanAM]

1. A definite possibility.

2. Possibly- especially if there is a compressor or alternator problem.

3. Not recommended as the newer design was setup for a different belt/pulley/component configuration.

[bassfisher89]

I’ve still yet to figure it out. Finally brought the boat to the lake today. At idle I’m still hearing a squeak but under a little load it goes away. New spring new pulley. I have not ran the boat at anything much past Idle not on plane etc. too afraid ��. Been busy the past several weeks so hopefully I’ll be able to dig into it more this week. I may run it by a local mercury guy just to see if I am missing something or installing the tensioner wrong. I know it’s simple that’s what’s killing me.

[EuropeanAM]

While idling, stick your thumb over the air INLET for the air compressor for about 1 second, and see if the "squeak" disappears. If it does, it may be a reed in the compressor (or an unusually aggressive seal in the air pressure regulator).