ST1100 Tension on new timing belt

[sbhead]

Posted this in my maintanence thread but no one commented, sorry to anyone reading this twice.

I replaced the timing belt two weeks ago and am wondering about the tension. I followed the manual with the whole three teeth past, but the tension pulley isn't pulled all the way up like it was before I loosened the old belt, there is still travel left that it could move up more. Is this okay? The belt has about 1/4" of play between any given pulleys. I still have everything opened up as I'm STILL waiting for the water cover to come in.

 

[PLUMMAN]

Re: Tension on new timing belt

I did this so long ago! I believe that the tensioner is spring loaded. Probably the old belt was stretched. So the belts should not move the tensioner the same amount. Follow the book and you won't be wrong!

 

[wjbertrand]

Re: Tension on new timing belt

As long as there's free movement of the tensioner assembly you should be ok. The timing belt does not depend on friction, it's toothed, but the tensioner is needed only to control any slop, not really to apply tension.
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[Ross Smith]

Re: Tension on new timing belt

I benchmarked my /99 with a new belt at 72k when I bought the bike using the Honda shop manual I had bought for it previously. If you're using that manual just follow those instructions and you won't have any problems.

Ross

 

[primus]

Re: Tension on new timing belt

I opened mine up today to have a look at the belt. I now know that the bike has 68k miles on it and not 27k that was showing on the duff speedo. I was a little concerned about the amount of play in the belt as I expected it to be quite taut. I reckon I had about 3/8" play, but as has been explained, the tension is governed by a spring loaded idler. The belt looks in really good nick. Getting the top hose of the radiator was the hardest bit for me. Thankfully all the fixings came adrift easily. I feel a bit more comfortable when I come to do the full job now. This really is a fantastic site.

Paul

 

[George]

The idler is not really "spring loaded." When ya install the new belt and follow procedure, the spring tension sets the belt to appropriate tension. But when ya tighten the idler bolt, the idler pulley is fixed in place 'til the next time the bolt is loosened.

I have this duty to do on lipSTick soon. New (Gates) belt is setting in the garage.

 

[primus]

Thanks for that George. Does anyone else have an opinion on how much play there should be? I'm not overly worried but any info will be gratefully accepted.

Paul

 

[Rick Gibson]

Listen to George, he as a ton on miles on 1100s.

 

[Ross Smith]

There is no belt free play measurement Paul. Just follow the new timing belt installation procedure properly and don't forget to tighten the belt tensioner idler bearing after completing that step. That's very, very important! Not only will it quickly fall out if you don't but you could likely damage the valve train on both cylinder banks immediately.

Your bike's timing belt is not a flat or v-belt. It requires only the specific initial tension supplied by the spring lever on the idler bearing. If you're overly concerned about tension because the spring doesn't look right or is badly corroded, then simply replace it with a new one when you replace the belt.

Again, as mentioned by others, a new belt must also be tensioned 3 belt notches past the index mark on the right cylinder bank pulley, (the cam pulley without the cover plate) before tightening the idler.

Replace the belt, aligning index marks properly, but leave the tensioner loose. Turn the engine over clockwise using a socket wrench until the belt makes a complete rotation, then position it as mentioned above before tightening it.

The 3-notch operation is done only once. If you remove the belt in the future and use it over again, don't move it past 3 notches again, just align everything with the index marks after running the belt around once.

Ross