Author Topic: A50 timing cover gasket  (Read 545 times)

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AdrianS

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A50 timing cover gasket
« on: 21 November, 2020, 08:18:20 »
Just a quick question..
Are all the timing cover gaskets interchangeable?
I’ve got my A50 engine in bits (to have the timing side bush done) and found a pack of various gaskets with an A65 copper head gasket. There is a timing cover gasket in the pack but there is no more on the pack as to what bike it is for. I note there are several thicknesses available

DAVE BRADY

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Re: A50 timing cover gasket
« Reply #1 on: 21 November, 2020, 10:04:13 »
'morning Adrian,

There are possibly 3 different timing case gaskets depending on the clutch mechanism.  I am not too sure about the early lever type but ball/ramp ones had two variations with the later ones having an extra screw and beefed up support for the clutch mechanism in the outer case.
I looked in my parts books and there is a lack of illustrations and numbers for gaskets for some years.

Dave.

Mike Farmer

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Re: A50 timing cover gasket
« Reply #2 on: 21 November, 2020, 10:57:55 »
 :) :) :)

What year is your engine. I believe that the early ones were the same. At least I only recall buying "a gasket".

Not too sure about different thicknesses but I could do with a thicker one to hopefully fix a persistent niggling little oil leak.

Mike 8) 8) 8)

AdrianS

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Re: A50 timing cover gasket
« Reply #3 on: 21 November, 2020, 11:42:47 »
Engine is 1962
I noticed that there were 2 different thicknesses available from some sellers. 0.4mm or 0.8mm

DAVE BRADY

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Re: A50 timing cover gasket
« Reply #4 on: 21 November, 2020, 13:02:30 »
Hi,

Don't forget that a thicker gasket on this joint increases end play on a few things.  Kick start, gear change and idler gear.

Dave.

Mike Farmer

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Re: A50 timing cover gasket
« Reply #5 on: 21 November, 2020, 15:36:09 »
 :) :) :)

Understood. The difference between 0.4mm and 0.8 mm is .016" about the amount of points setting. Would you consider that a significant difference. I ask because it could well solve my problem. I suppose that I could always put a shim in those places. Would it make a difference to the timing backplate in relation to the points/electronic pickup. I think probably not.

Mike 8) 8) 8) 8)

DAVE BRADY

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Re: A50 timing cover gasket
« Reply #6 on: 21 November, 2020, 16:07:26 »
Hi Mike,

Not a lot of difference and the only place it might be relevant is the idler gear.  I can not see it making any difference to an EI pickup but it could make the idler gear a bit noisier.  The movement of this gear is limited by the faces on the bushes so it is worth keeping an eye on this.  I think this play is one of the sources of rattles on A65s.  On a recent build I found about 30thou of play with unused cases.  This seemed a bit too much so I shimmed it to give about 12.
I think it has made the engine a bit quieter.

Dave.

AdrianS

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Re: A50 timing cover gasket
« Reply #7 on: 21 November, 2020, 16:40:54 »
Interesting to hear about idler gear noise. While I was trying to diagnose my strange engine noise, one mechanic suggested changing the idler gears as he had found that changing them sometimes quietened the engine down. He did not think my noise was bottom end or terminal. However when I pulled the barrel I soon found out there was a lot of play in the timing side crank bush so the engine had to come out!

DAVE BRADY

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Re: A50 timing cover gasket
« Reply #8 on: 21 November, 2020, 16:51:17 »
Hi Adrian,

It is always best to check for worst case scenario as it will save money in the end.  With a rebuild it can be assumed that all the usual suspects have been done properly so worth checking these things like the idler gear.
One of the biggest sources of A65 noise is the primary case.  The other day and for no real reason, while my engine was ticking over I put my open hand on the primary cover and the noise reduction was quite noticeable.  It is a bit of an echo chamber so I wonder if there some amazing glue that could stick something to the inside to dampen it out?  Ditto rocker cover.

Dave.
 

Martin S

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Re: A50 timing cover gasket
« Reply #9 on: 25 November, 2020, 11:51:46 »
The car industry uses sound deadening pads on the inside of panels which are cured when the paint is baked, but I'm not aware of any that would survive inside the primary chain case or rocker cover, and they would not look very pretty on the outside.

How about fitting an aluminium pad on the inside? It would need mounting holes to be drilled in the covers, which certainly wouldn't be seen on the rocker cover. A quick check with plasticine would tell you how much clearance you have. The mounting holes would be yet one more source of potential oil leaks, but we're used to chasing them.

DAVE BRADY

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Re: A50 timing cover gasket
« Reply #10 on: 25 November, 2020, 12:15:03 »
Hi,

It would be a bit of a disaster if something came adrift in the primary case or rocker box.  Some primary covers had a criss cross pattern cast on the inside perhaps to reduce this resonance so maybe that is the answer.  I suppose the best solution is to just ride it so the noise becomes an irrelevance and earplugs work wonders.  I am convinced that my bike goes much faster when I wear earplugs.

Dave.

Martin S

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Re: A50 timing cover gasket
« Reply #11 on: 25 November, 2020, 12:40:07 »
You're right, the ribs are there to reduce resonance, but they're not deep enough to make much difference; the science of sound deadening was not very sophisticated then. Funny how ear plugs improve a bike's performance, works every time

chaz

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Re: A50 timing cover gasket
« Reply #12 on: 25 November, 2020, 12:58:40 »
this is a problem Harley Davidson had with their latest redesign. the engines always being on the noisy side, this was the problem that the latest noise and emissions rules caused. Harley , like the British, always used air/oil cooling but the Japanese went water cooling. the water jacket reduced noise. Harley's latest engines (Electric excluded) had to be redesigned to build in soundproofing. The water cooling did upset some old timers but it kept the company in the fight.

idie

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Re: A50 timing cover gasket
« Reply #13 on: 25 November, 2020, 13:21:54 »
If you want to fix an alloy plate inside the cover use JB weld. I repaired the sump on an RT bus with JB weld and it never came adrift even though it was immersed in oil.