Persistent noise after timing belt change

[wingandaprayer]

I think the Apr 9 backup issue made previous posts unavailable?

- I changed timing belts, using NAPA belts.
- I have a "whistling whine" coming from the front of the engine at 1200rpm idle. It goes away when you throttle up.
- other forum members noted if belt tension is too tight a whine will be present. Retension belts is cure.
- I opened up the cam drives again, and I did the retension procedure, very carelfully, double checking. I thought one belt was on the tight side. I have 5 mm of slack at 2 kg force on both belts. (loose end of the specification). I run the engine before closing up the drives for 10 - 15 seconds and thought it to be quiet.
- I buttoned everything up and the engine again makes the noise.

I would not describe the whine as a "belt whine" - like an OHC engine like a 1600 or 1800 Mazda Miata engine makes when you wind it up... it has a high pitched "whistle" sound and goes away when you pick up the rpm by 100 or more.

I am thinking that while the tensioner bearings felt smooth, one of them could be on the dry side and unhappy?

[neoracer]

i changed my belt when i did my poorboy using napa belts,just renumbered/letterd gates belts actually

i had a noise to at idle that went away after i got a few more miles on it,if it doesn't get worse i would just see what happens u may just chasing a "phantom"

4K later no problems

[alnvan]

When changing rad. coolant and hoses at 40,000 Miles I decided to check on the timing belts. I found the right to have over
an inch of play and the left about 1/2 inch, it was time to replace them. After installing new Gates/Napa belts and checking
the tension by the trigger method as outlined on previously forums, I'm hearing a whirring noise. At idle (1040) just noticable at higher RPMs it is not noticable (engine noise?). I notice it more when I stop the bike after a good run (metal expansion or less engine noise?) and will be checking It if it has not gone away after 4k miles.

[bluewing]

When I purchased my wing the P/O told me he had just replaced the timing belts, I didn't know much about the bike at the time. I took my bike to a Honda mechanic that I know to get the bike certified and I ask him to check out the wining. When I went back the next day he showed me the problem, the timing belt were adjusted too tight and the timing belt covers were full of powder dust and the belts were over half worn out. The mechanic told me if I had kept driving it like that I would be replacing the motor or at least some expensive parts. After the new belts were put in properly the whine was gone.

[Guest]

I too have the same problem.I used the Gates/NAPA belts and even went back in a second time to re do the tensioning procedure.Alas, belt noise still with me. Today my Honda factory belts arrived and I will see what, if any difference, these make.Now that I think of it, one thing that was odd about the first pass at belt installation was I had to remove the bottom pulse generator in order to get the right belt on.No mention of that from the tech manual. Hmmmm.On the up side, I did get factory Honda belts to my door for $154.00. Pricey,but cheaper than the potential for destruction.
Noisily, Patrick

[wingandaprayer]

As I mentioned I rechecked the tension of the belts and moved them to the loose end of the specification. Last evening I gave the front cover area a good going over with a mechanic's stethoscope with the engine warm and idling at 1100 rpm & making the noise... I am thinking it is the right side adjuster idler... anyone remember the noise your failing Delco alternator bearings would make on your 70's Chev pickup? Lower that noise down about two octaves...
Wet weather is coming so I am going to open up the front covers again and check it out - I think I will re install the rad without the timing covers in place and run the engine and get to the issue.

[Guest]

As of now noise is gone. Installed factory Honda belts and went over the tightening sequence three times.Rode the bike w/o false tank and fairing lowers and heard no end of racket in general.Oh, checked water pump while in there,not too bad, considering I drained green coolant out and flushed before installing blue coolant the first time I did belts. Well, I'm tired, dirty and $155.00 lighter, but I feel much better about the job now.
Quietly, Patrick

[neoracer]

so your thoughts are that it was the napa/gates belts then

did they show aqny kinds of wear or anything?

[Guest]

The factory belts were thinner and went on a whole lot easier than the aftermarket.Is it just me, or with the timing marks all set for belt change, there is a reluctor thingy on the crank pulley that precludes removal of left belt without moving the pulse generator out of the way. No mention of this in any postings or the Honda manual.
Belted, Patrick

[roscoepc]

The best I remember there is something, the pulse generator I believe, that I did have to remove to remove and install the belts. The reason I remember is that I tried to crank the bike and it wouldn't fire till I re-installed the dam thing... :-

[wingandaprayer]

The factory belts were thinner and went on a whole lot easier than the aftermarket.Is it just me, or with the timing marks all set for belt change, there is a reluctor thingy on the crank pulley that precludes removal of left belt without moving the pulse generator out of the way. No mention of this in any postings or the Honda manual.
Belted, Patrick

Patrick - glad you have the issue fixed. Interesting you mention the Honda belts are thinner. I did notice that when I unpackaged the NAPA belts. They seemed thicker than the Honda belts that I was replacing. However, near as I can tell by previous owners' paperwork I have, the belts on my engine were original - 25 years old, 50,000 miles. You would have thunk that would have been my first clue to buy genuine parts. In my previous post I am saying the noise seems more on the right side drive - the pitch of it has me thinking tenisoner pulley bearing... but... if the belt is thicker, it's teeth may be engaging the drive and driven pulleys just differently enough to set up the racket at that engine speed (1100 rpm). neoracer mentions noise at idle with new NAPA belts, that eventually went away. What has me thinking this way is my NAPA belts were not "matched" - one had yellow NAPA branding, p/n, "made in USA" while the other had p/n only, and "made in USA" - maybe made by different suppliers? Who knows? I "saved money" that was the key... - my bike sounds like junk at a stop light but I saved money. :YMAPPLAUSE: .. one advantage is I can take apart the bike to the cam drives now in record time..(have I mentioned my new bike lift?. :d .) ... so I will order Honda belts to have on hand with idler pulleys, take it apart again, and fix it. And report back to this thread.

[wingandaprayer]

Reporting back as promised -

- original tensioner pulleys were (still) very smooth and quiet. Installed the new ones anyway.
- replaced belts with Honda belts.
- whistling/howling noise is gone.

One noise shows up at 1100 rpm, not 25 less or more. Methinks it was there all along, a coming together of frequencies so to speak. I made the mistake of taking the bike out of winter storage straight into the shop for the work, before riding it and getting used to what sounds were happening before ("normal") and what could be new.
I think the belt noise at low rpm/idle/around town would eventually quit, (or not)... if a guy could put up with the noise they were making for a few thousand miles I bet they would wear in and be quiet. The noise at road speed could not be heard if it was there. I don't think any disastrous breakdown was iminent.

Ride safe everyone.

[85GL1200I]

Thanks for following up with that post.

always good to hear the bottom line...........