1997 Honda 9.9 rubber mounts worn out ??

[raf235]

I've just fitted a 1987 Honda 9.9 to my 16ft cruiser (for inland UK use with speed limits).<br />I gave it a service (oil, leg oil, plugs etc.), and it runs really well, I don't think it's had a lot of use).<br />The slight problem is that although it runs lovely and quietly and smoothly at tickover and above 3000 rpm, when used at 1500-2500 in gear, there are slight extra random sporadic resonance/vibration/noises (that irritate me !)<br />I noticed when fitting the engine that when tilting it, you can actually get the engine to 'clonk' in it's upper rubber mounting bushes, i.e. although 'floating' normally, they can be pulled to metal to metal contact. They look OK externally and there appears to be no adjustment (just nylock nuts done up tight on the inner sleeves). Do they wear out ?<br /><br />Thanks in anticipation of the usual great responses I get from this forum, it's one of the main highlights of the web for me !

 

[hondon]

Re: 1997 Honda 9.9 rubber mounts worn out ??

This engine is no spring chicken,so first determine whether or not your motor mounts are living up to their expectations.Give that engine a really hardy shake ,back and forth ,pull it from the bottom out ,push from the bottom in,.If you are a big boy ,you will get an inch,at the most of flex at those mounts ,and be able to see if they are flexing or unglued at the mount.

 

[raf235]

Re: 1997 Honda 9.9 rubber mounts worn out ??

Hi Hondon,<br />Thanks for the response.<br />I was a bit taken aback by your 'Spring Chicken' comment, but then I realised I had mistyped the decade !<br />It's a 1997, so it's only 7 years old, and was used by the previous owner infrequently on a Canal Boat at 4mph, so I don't think it's had a lot of general wear and tear.<br />On this particular type, I can only move the top quite a bit less than an inch, but the movement is then stopped by the metal to metal contact, or 'clonking' as I put it. In fact, whenever you fully tilt the motor, you get the clonk as it's pulled up and forward, and you get the impression that it's then resting in the metal to metal position under it's own (horizontal) weight.<br />I've checked the price of the mounts with the dealers here in the UK, and they're £34 ($50 US) EACH !, so I'm desparate to find out if this this softness is normal before I spend £70 for two small bits of rubber.....<br />I'm thinking that this is what causes the random vibrations/buzzing at 1500-2500 revs from the whole unit, which is otherise lovely and quiet and smooth from 1000 to 4500 revs.

 

[hondon]

Re: 1997 Honda 9.9 rubber mounts worn out ??

Are you seeing actual wear on metal surfaces?Only you can explain to us where this "CLONK" is coming from.Sounds as though the mounts are intact,however the tilt mechanism may be corroded and not operating properly or have bent or missing parts.Look carefully there.Harmonic vibes are nothing new in this industry and can happen with any engine /boat combo.Hope you are not chasing your tail.

 

[gss036]

Re: 1997 Honda 9.9 rubber mounts worn out ??

After reading this, I had to go check on my 15hp Honda, about same vinage, and the mounts look like they are split, but actually not and works fine. I think what you are hearing is the spring loaded system that holds the tilt position and yes it does rest on metal to metal when tilted. <br />I broke some parts on my a couple years ago and took it apart and fixed myself because the local honda guy wouldn't look at it for 2 weeks. I now understand why they have engineers that design this stuff. It works but I thing they made it too complicated. I put a couple of bungee cords on mine to keeping it from bouncing around while it is tilted up and to protect the tilt parts when I am up and running w/big motor. The small motor bounces around a lot in rough water. I know of several guys around here who have broken the tilt mechanisn the way I did.

 

[raf235]

Re: 1997 Honda 9.9 rubber mounts worn out ??

Thanks again for the helpful responses....<br />I've had another careful look at the motor and it's very difficult to say where the metal contact is. The tilt mechanism and steering tube look fine and seem to be all there and working smoothly. It occurs to me that in normal use (forward drive), the head is being levered backwards, away from the boat, and in that direction there is no metal to metal clonk, just a nice firming up of the mount. I tried the motor out today, in gear whilst moored to the bank, at 1000, 1500 and 2000 revs, and the spurrious rattle was very slight, even with the casing off, so I think maybe I am 'chasing my tail' !! <br />It would be a real bug*** to spend £77 ($110) to find it made no difference !!

 

[gss036]

Re: 1997 Honda 9.9 rubber mounts worn out ??

How is your prop? Any vibration from it or lower end. I just don't think it would be the rubber mounts.

 

[raf235]

Re: 1997 Honda 9.9 rubber mounts worn out ??

No, the prop is like new.<br />It's a very slight vibration at 1500 to 2500 revs which sets up a light sympathetic rattling from other parts of the motor, but it's not consistant, and usually goes away when you push the motor back and forth to settle it on the rubbers. <br />It was reassuring to hear that you also get the metal to metal contact when tilted (that was the bit I wasn't sure about) ...<br />I think Hondon's right, and that I'm 'chasing my tail'.