Honda GXH 50 & HS valve rattle problem

[Irish John]

I always thought that the valves on both these motors rattled and that it was just a fact of life that I had to put up with. That ringing metallic sound that really doesn't impress the spectators and detracts from the nice burble and dulcet tones of a good four stroke etc.
I keep my valves set exactly as per spec but I find the nasty ringgggg-ding ding ding sound is the centrifugal clutch clipping the bell housing at low revs.
This should be fixable and the spectators will stop laughing as I approach.
I might try a stronger spring around the clutch. I've tried reversing the clutch but that was so the pads wore more evenly after 4000 kms they became noticeably more worn on one side so I turned the clutch around to even the wear That shouldn't matter one iota I reckon cos it works the same either way.
Has anyone got any suggestions as to stopping the ringing clang so I can reclaim my lost street cred and impress the great unwashed as I blast by on my Indian Pacific Honda Grubee. Tell me I'm not the only victim of this embarrassing tinny din. You all get this nasty noise dont you? You all see them s******ing in your rear view mirror.

 

[biketec]

try to tighten the bolt a bit that holds the gear on the crank and if that doesn't work you may need a new bushing on there. That bushing is there to prevent the wear of your crank like a hoot and may be in need of replacement. The Hoot box will wear your crank down and eventually need to replace it so I'm told. But try to tighten it up if that doesn't work buy a new bushing, There should be no side to side play.

 

[Irish John]

Thanks Biketec, that is great advice. The bolt is very very tight but there was side play always since it was new. I don't think the bushing is worn but I think it can be made tighter by making a slightly wider shaft key for the bushing so there is no play. I'll take it apart and find the best way to tighten it up. How do you avoid this happening? I reckon some gear boxes are just a bit looser by a couple of microns.

 

[biketec]

yea there made to wear out grease on them help prolong the life a bit some bushings are a hair smaller than others so IDK you know the shipping thing if I can I will look into a small envelope or somethin if you would like.

 

[Irish John]

yea there made to wear out grease on them help prolong the life a bit some bushings are a hair smaller than others so IDK you know the shipping thing if I can I will look into a small envelope or somethin if you would like.

Thanks so much Biketec. What I've done subsequent to your advice is to file the inner end of that bushing back so it fits tight against the clutch with nil lateral movement - might be too tight now cos I filed a wee bit too much. This has greatly helped but there is still a bit of a ding ding at low revs but not as bad. The clutch bites now when gear engager is pulled on - even at low revs - but I can live with that so long as the ding dong is less.
Those carbies were great BTW and thanks for the grey plastic chokes. This Honda on the Alloy Schwinn is so fast it scares me. Looking seriously at telescopic forks with a front disc to help me to stop. My gearbox has 6000 kms on it and still going good. I will be trialling some special liquid grease soon which will drip back onto the gears off the surrounding casing. I'll report it on a thread if it's any good. Not pinning my hopes on it and I'm only trying it out of curiosity. It's not like a wet gearbox or anything.
Almost time for you to put the chains on your tyres again Biketec!

 

[Irish John]

The mystery continues

yea there made to wear out grease on them help prolong the life a bit some bushings are a hair smaller than others so IDK you know the shipping thing if I can I will look into a small envelope or somethin if you would like.

I got a new bushing and installed it but the clutch still ding dongs at medium low revs. I tightened the clutch by hammering the key under it and up the far end where the keyway slopes upwards. The whole assembly felt tight as a drum with no play. Maybe the bushing wore out the inner lining of the clutch bell where the bushing goes into it and it's that that is loose. The bushing was a very tight fit in the clutch bell though so that's unlikely. Maybe it's that I don't have a gasket between the gearbox & engine cos it wore out. Can't think what it could be. I could try a new clutch and new gasket. I have spare ones of those. I just don't like the noise and the looks I get.

 

[Irish John]

Can't resolve clutch clanging

It's no problem regards the bikes performance but I can't stand the clutch clanging and I can't solve it. The Honda\Grubee hit 62 km\hr today on the flat but that clanging is like tubular bells and it bugs me. I reckon it's maybe just wear and tear in the GB which has done 6000 kms or so but it looks OK.
Would a new centrifugal clutch help I wonder - I could use the one from the Hoot cos it's from the same Govt. factory that they all come from and they are all the same I reckon except the shaft key groove on the Hoot clutch is a bit more slovenly cut than on the Grubee. Precision-made they certainly ain't!

 

[ZnsaneRyder]

Most clutches make that dingy noise. I spray WD-40 on my clutch to make it less grabby and it quiets it way down and the noise goes away mostly. The dingy noise is normal though when a clutch is dry. Watch a go-kart drive around, and you will always hear that noise from the clutch when letting off the gas pedal.

When the clutch is engaged, it won't ever make that noise, only when the clutch is not fully engaged. If the noise is bad at low or medium revs, you need to give it more gas to keep it locked. If you drive the engine too slow, the clutch will partially slip and be very noisy and it heats the clutch and destroys the bushing. Drive faster to keep the clutch fully locked, and pedal much more instead of riding on the clutch at slow speeds.

Lowering the RPM of my clutch springs made a significant improvement on my clutch noise. The clutch grabs quicker and rattles less because it now takes less RPM to lock and slower speeds are much easier. You may want to try that on your clutch.

Just some tips that may help.

ZnsaneRyder

 

[Irish John]

Thanks Znsane, what exactly did you choose to replace the stock spring with? I'll try the WD40 and see what it does but I don't think using a looser spring will help cos that spring is OK and used to be quiet until recently. The spring will have become less powerful over the 6000 kms it has operated. The clutch doesn't grab but I think the spring beiong old maybe is too worn and needs to be replaced with a newer one that is stronger and pulls the clutch together at low revs so it's not clanging about. I reckon a stronger spring is the answer maybe if indeed the spring has any bearing at all on the problem.

 

[ZnsaneRyder]

My clutch is somewhat different, and it has 4 C-shaped springs, and they directly swap with different rated ones. But regardless of what clutch, they all get noisy over time. A NEW clutch would solve your noise problem for sure. The metal surface gets rougher, and the shoes may not match up perfectly anymore, but it still works fine. The springs do get weaker over time as well, and that may help a bit, but if a clutch is locked, it makes no noise. You don't get the noise at idle right? Your idle is low enough to where they aren't touching?

I'll admit, my idle is a bit high, and mine always rubs very slightly and makes some noise, but I lube it and I like it that way because the engine runs better with higher idle, and the power is more sudden and smooth when it starts to go with a small bit of throttle.

You must have a really quiet engine to hear your clutch that loud. If the clutch is worn out, then change it, but I prefer to run it until the end, so I deal with the noise. If you have the money to get a new clutch, then get it, and keep your old extra clutch as a working backup in case something goes wrong with the new clutch, or if you find yourself needing a clutch for another motor in the future.