squealing Honda outboard

flatfishfool · Posted: Fri Jun 12, 2020 6:28 pm Post subject: squealing Honda outboard

Hi all, I have a new to me 22CD cruiser with twin 2001 40HP Honda's, carbureted obviously, just under 1300 hours. They have had timing belts done and one had a new lower unit (date unknown).

I recently took it for its first shakedown cruise at a large lake and have an issue with the port side motor where it makes a fairly loud squealing sound when running in the 2000-2500RPM range. Outside that range I do not hear anything and in the hour or so we ran it that day it otherwise seemed totally fine. Squeal sounds like you'd expect a belt to sound like, like when a car water pump or power steering pump is going out. I pulled the cowling off underway and it sounded like it was coming from the engine vs lower unit, though it's very hard to tell.

I have done a bunch of searching on C-Brats and elsewhere to try to diagnose. The only clear lead I have is reference to Yamaha and Merc outboards of similar vintage (and newer) where they make a belt squealing sound at various RPMs, but typically just in a range of RPMs. Diagnosis is a little fuzzy but has something to do with the drive shaft and either the seal at the top of the lower unit or the shaft itself needing lubrication. But I have not found anything about this and Hondas. I will probably try the fix since I am waiting for professional help.

I also found a reference to a high pitched "tinny" whine akin to rubbing your finger around a crystal wine glass and some sort of Honda aluminum prop harmonics, but I think the sound I am hearing does not match that description so I am skeptical that's my problem.

I pulled the cover and plastic off the top and the timing belt looks totally fine, no deterioration or dust all over etc, and tensioner pulley looks very clean and like it was replaced with the timing belt as you'd expect, though I can't be 100% sure. I didn't take any of that apart since it starts to get deeper there.

I am in line at several outboard shops but since that is a long and perilous path this time of year and I am reluctant to use it until I resolve, I thought I would ask the brain trust if anyone has ideas. And yes I have been following the twins repower thread with a very specific curiousity.

flatfishfool · Posted: Fri Jun 12, 2020 7:27 pm Post subject:

Did a bit more reading and the drive shaft diagnosis seems to be described as the "top drive shaft bushing".

Pacificcoast101 · Posted: Fri Jun 12, 2020 8:34 pm Post subject:

I've had the driveshaft bushing fail on two Honda outboards this year. The first time the shaft got so hot it split in two. The second time, I shut it down immediately. I keep my boat in a slip, so it's in a salt water environment all the time where it gets corrosion.

Barry Rietz · Posted: Fri Jun 12, 2020 11:21 pm Post subject: Squeal Noise

Since you indicated the noise sounds like a "belt and pulley" squeal, why not try readjusting belt tension. Then if the noise persists, try a bit of belt dressing before digging deeper into the mystery. Start with a process of elimination by doing the obvious and easy things first.

Blue Rose · Posted: Sat Jun 13, 2020 9:22 am Post subject:

A bearing going bad can make the squeal you describe. It is possible the tension pulleys were not changed with the belts. You can't visually see if the tension pulley bearing is worn. Running the engine with the cowl and plastic cover off may help you locate the noise. I would put in a new tension pulley and adjust the belt tension. It's easy to do yourself. The part is about $75. If that fixes the squeal I would change the pulley on the other motor too.

https://www.youtube.com/watch?v=o9tau2K3ej8

Jim

T.R. Bauer · Posted: Sat Jun 13, 2020 5:42 pm Post subject:

What you are describing could be several things. Is it just those RPMs? Or is it just those RPMs, but only under power with the lower unit engaged? I ask because it matters...

flatfishfool · Posted: Sun Jun 14, 2020 5:56 pm Post subject:

Thanks for suggestions all. I am about to undertake lubricating the drive bushing and see where that gets me. Seemingly fairly simple to drop the lower unit for this. I will also see if I can get a timing belt tensioner pulley here in town tomorrow and if not order one and this will be my next step if nothing else comes to light.

To the question of whether it makes the sound both out of gear and in gear, good question. I just hooked it up to the hose and ran the RPMs up in neutral and got no sound. Unfortunately I also put in gear on the hose and ran it up and didn't get the noise either. This suggests it needs to be under load which I think also points more to the bottom end than the top but that's just intuition not experience talking.

I welcome more ideas and will report back.

Pacificcoast101 · Posted: Sun Jun 14, 2020 6:24 pm Post subject:

The first time I heard the noise was when I started the motor in the slip. It stopped after a few seconds, but after a few hours on the ocean, it returned as I was pulling back into the slip. I still didn't know what it was and stupidly went out again. This time it was louder and suddenly I couldn't get the motor in gear. The shaft had split.

After replacing the shaft, bearings, and water pump, the same noise occurred on my port motor. This time, I had everything replaced before the shaft broke.

Moxieabs · Posted: Sun Jun 14, 2020 7:50 pm Post subject:

My 2003 Honda 90 made a similar sound to your description(squealing/singing) at about the same RPM only in gear & changing the prop stopped it.

flatfishfool · Posted: Mon Jun 15, 2020 1:54 pm Post subject:

Well I had the lower unit off and to my chagrin I think these small Honda's don't have a bushing as the shaft splines appear to go all the way up into the bottom end of the engine with no other connections or constricted passage etc.

So I took the opportunity to lunbricate the drive shaft splines a little and to inspect the top of the sealed gear box and water pump etc. And I learned how to take the lower unit on/off so that was educational.

I did forget to initially mention the motors had sat for almost two years and not been run until this spring. When they were put away in 2018 they had new motor oil and gear oil ane carbs drained etc so were properly stowed.

I'm a little shy about messing with the timing belt system given the consequences and some of the subjectivity of the process ("the belt should be tight but not too tight") but I am now moving on to the tensioner pulley possibility.

Moxieabs, would you describe your noise as a squealing versus a more refined pitched hum or whine? Mine was definitely on the harsher end hence my use of "squeal".

tsturm · Posted: Mon Jun 15, 2020 8:21 pm Post subject:

flatfishfool · Posted: Tue Jun 16, 2020 4:48 pm Post subject:

I took the boat down to the port in Anchorage and used the ramp to stick the props in the water and run under some load to try to hear the noise again. This is the closest place available but is unfortunately not a good place to actually launch and run around for this purpose so it was still on the trailer and tied to the dock.

With varoius iterations of running from idle up to 3500 RPMs I was largely unable to replicate the sound I had when underway. I had a little bit of intermittent whining but it did not seem as significant and I would say was possibly more of a prop harmonic sound than a belt squealing sound. I also took the tops off and watched both motors and timing belts run and used the screwdriver trick to listen to the tensioners on both motors. They sounded the same.

Not exactly a resolution to my problem but I think I'm just going to fuel her up and make a run out in the Sound and see what happens. I'll also take my mechanic appointment if it ever comes up (I'm 91 on the list, they are in the 30s) but will not authorize too much of a fishing expedition.

Familiarity with a boat's quirks takes time to settle into. Hopefully I won't have a follow-up posting other than a thumbs up. Thanks for all contributions here. I'm going to go catch up on that twin 60 repower thread...

drbridge · Posted: Tue Jun 16, 2020 5:32 pm Post subject:

We have a 2004 Honda BF90A. When we run the solas 3 blade aluminum prop we get a ringing/squealing just a little above an idle while in gear only. this is the speed that we use going in and out of the marinas and it drives me crazy. We have another 4 blade prop that I prefer to run most of the time and it makes no noise. If I switch back to the 3 blade it comes back. If you have another prop or can borrow one you might try switching them around to see if that is the problem. No mater which prop we are running I always carry another for a spare just in case. It is pretty cheap insurance.

Moxieabs · Posted: Fri Jun 19, 2020 3:52 pm Post subject:

I would say its was more od a "squeal" and always got comments from slip neighbors about "the belt slipping" on my motor.

flatfishfool · Posted: Sun Jun 21, 2020 3:49 am Post subject:

Took the boat to Whittier yesterday and ran her for a few hours. Definitely heard my sound at 2500 RPMs but have now convinced myself it’s the prop noise issue. The clincher was I realized the sound was the same with the cowling on or off. If it was originating in the engine I would not expect this. Still possible it’s lower unit issue of some kind or something. I’ve decided to just run it and we’ll see. I did do a brief video of it and posted to my album. It’s not great, at least in part because I didn’t include any time in the vid without the sound as a comparison. Thanks again for all the ideas and help.

http://www.c-brats.com/modules.php?set_albumName=Slack-Tide&id=trim_76708692_CFBB_4E2A_B414_08B2FE119533&op=modload&name=gallery&file=index&include=view_photo.php