Author Topic: Engine Rattle- Valves or more sinister?  (Read 970 times)

Offline Raygun

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Engine Rattle- Valves or more sinister?
« on: December 16, 2021, 11:18:55 AM »
See below for a little video- it's present at all revs and proportionate to the rpm- i.e louder with more rpm.

the cam chain has just been adjusted (this morning!) and the tensioner appears to be working fine. Next step for me is to check valve clearances though these were done just before the bike got on the road less than 100miles ago- so unless there is a bedding in/loosening they should be OK. Engine was fully rebuilt less than 100miles ago

Bike starts well, revs well, isn't hanging and only a little smoky. Seems to have good power

What does this noise sound like to any of you? I'm always conscious I don't know how these engines should sound- how much top end nose is normal....

I've searched around but it's quite hard to work out the different versions of engine noise people mention from other posts, so any help appreciated!

https://www.youtube.com/watch?v=wg7nd52LATw
« Last Edit: December 16, 2021, 12:04:09 PM by Raygun »

Offline paulbaker1954

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Re: Engine Rattle- Valves or more sinister?
« Reply #1 on: December 16, 2021, 12:32:46 PM »
Im no expert but mine rattles as well when cold. I think from what i have seen over the years on various sites this is not unusual

Did you change the primary chain on the rebuild as this doesn't
 sound like valves to me
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Offline McCabe-Thiele (Ted)

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Re: Engine Rattle- Valves or more sinister?
« Reply #2 on: December 16, 2021, 12:47:36 PM »
My 400/4 sounded like that when I had it running for the first time after standing for 12 years  - I'm inclined to think it's just a tad tappety - Is there plenty of oil visible at the top end when you undo a tappet cover - I'd check the valve clearances again for peace of mind.

Most of my experience is on car engines - they do bed in especially if there are any new moving parts in the mix.

If the Hondas were not so well silenced we would not hear a lot of the sounds that make us worry needlessly.

This was mine - not had it running yet since the rebuild.
https://www.youtube.com/watch?v=SWwb3LgNpIY
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Offline kevski

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Re: Engine Rattle- Valves or more sinister?
« Reply #3 on: December 16, 2021, 01:27:41 PM »
Can hear the clutch basket rattling,  as well as a loud metallic  tick, carbs balancing would probably benefit the motor, if you are in an enclosed space it will sound worse.

Offline Sesman

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Re: Engine Rattle- Valves or more sinister?
« Reply #4 on: December 16, 2021, 01:50:55 PM »
Sounds fine to me.

Offline heli_madken

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Re: Engine Rattle- Valves or more sinister?
« Reply #5 on: December 16, 2021, 02:55:38 PM »
Yep same here sounds fine to me

Offline murdock

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Re: Engine Rattle- Valves or more sinister?
« Reply #6 on: December 16, 2021, 09:17:43 PM »
Yes, there is a tinkling sound, are you sure it is inside the engine?

Offline AshimotoK0

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Re: Engine Rattle- Valves or more sinister?
« Reply #7 on: December 17, 2021, 01:26:41 AM »
Could it be play in rocker shafts between the shaft and  'egged' rocker cover shaft bores? (shafts rotate in cover and wear the cover bores)

Explained here:- (don't think his fix is the way to go though as a long term solution)

https://www.youtube.com/watch?v=MDIkDb_HhKw
https://www.youtube.com/watch?v=gDDK6ZOxmno
« Last Edit: December 17, 2021, 08:27:01 AM by AshimotoK0 »
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Offline Oddjob

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Re: Engine Rattle- Valves or more sinister?
« Reply #8 on: December 17, 2021, 07:51:55 PM »
Bottom end chatter, most likely primary chain banging around, a carb sync may help that. Is the clutch basket shimmed out?

Rear brake lever is far to high BTW.

Top end, did you inspect the rocker faces? I'd recheck the clearances as well, they can change as the head beds down.

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