1965 csr crank shaft.

Information relating to the Matchless G2 or AJS Model 14 250cc Lightweight
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dave16mct
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Re: 1965 csr crank shaft.

Post by dave16mct »

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clanger9
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Re: 1965 csr crank shaft.

Post by clanger9 »

Bolt the crankcases together with the crank in and the drive side shaft should slide (with persuasion) through the outer ball bearing. You're looking for at least 40 thou movement to make sure there's enough lateral clearance between the timing side of the crank and the timing side bearing (otherwise it might nip up when hot...).

There's no way to adjust this, it's just a check. The endfloat reduces to zero once the sprocket is fitted. The whole crankshaft is held laterally by that one ball bearing.

[The early Lightweight engines had two ball bearings instead of one ball and one roller. I have no idea how they assembled them. I guess they just dropped a heated crankcase over the two bearings and hoped for the best!]

It's an odd design - but very easy to assemble once you figure out what's going on...
1989 Moto Morini Dart 350
1993 Ducati 750SS
ColourNcoat
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Location: Monmouthshire UK

Re: 1965 csr crank shaft.

Post by ColourNcoat »

dave16mct wrote:Have you got this one:
http://archives.jampot.dk/book/Workshop ... CHABLE.pdf

Dave.
:beer: Dave, I have so many downloaded and remember seeing it but never known a bike that creates so much confusion and misinformation :D
Will continue to read.
Really appreciate all info :beer:
Roger.
ColourNcoat
Posts: 140
Joined: Thu Oct 22, 2020 8:07 pm
Location: Monmouthshire UK

Re: 1965 csr crank shaft.

Post by ColourNcoat »

clanger9 wrote:Bolt the crankcases together with the crank in and the drive side shaft should slide (with persuasion) through the outer ball bearing. You're looking for at least 40 thou movement to make sure there's enough lateral clearance between the timing side of the crank and the timing side bearing (otherwise it might nip up when hot...).

There's no way to adjust this, it's just a check. The endfloat reduces to zero once the sprocket is fitted. The whole crankshaft is held laterally by that one ball bearing.

[The early Lightweight engines had two ball bearings instead of one ball and one roller. I have no idea how they assembled them. I guess they just dropped a heated crankcase over the two bearings and hoped for the best!]

It's an odd design - but very easy to assemble once you figure out what's going on...
Great info, will digest all of this and move forward :beer:
Regards Roger
ColourNcoat
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Joined: Thu Oct 22, 2020 8:07 pm
Location: Monmouthshire UK

Re: 1965 csr crank shaft.

Post by ColourNcoat »

I don't know if anyone has come across an issue where the bearing ( 012543 ). The roller race had been put in and made a groove in the big end nut and pin.
This would suggest the race was not pressed into the crank case for correct positioning.
There is no thrust washer or inner or outer edge to the race.
Hope my theory is correct as I pressed the race into the crank case first.
Regards Roger.
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clanger9
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Re: 1965 csr crank shaft.

Post by clanger9 »

I guess they can move. The manual says to stake the race in place. I used bearing lock and it's still there...
1989 Moto Morini Dart 350
1993 Ducati 750SS
ColourNcoat
Posts: 140
Joined: Thu Oct 22, 2020 8:07 pm
Location: Monmouthshire UK

Re: 1965 csr crank shaft.

Post by ColourNcoat »

clanger9 wrote:I guess they can move. The manual says to stake the race in place. I used bearing lock and it's still there...
I staked the bronze bush and as you said used thread lock on just about everything that could or would come loose.
The engine is nearly done but need to find the seal which goes behind the clutch basket.
Thanks again all :beer:
Roger
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clanger9
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Re: 1965 csr crank shaft.

Post by clanger9 »

Good progress!
The "seal" behind the basket is a cheap item: http://www.amoc-parts.com/store/comersu ... duct=23700
1989 Moto Morini Dart 350
1993 Ducati 750SS
ColourNcoat
Posts: 140
Joined: Thu Oct 22, 2020 8:07 pm
Location: Monmouthshire UK

Re: 1965 csr crank shaft.

Post by ColourNcoat »

clanger9 wrote:Good progress!
The "seal" behind the basket is a cheap item: http://www.amoc-parts.com/store/comersu ... duct=23700
That's all sorted thank you. Obviously the gearbox is in after finding out the band tensioner threads were stripped and the screw cap for the oil pump threads were also damaged.
There is one question that is puzzling me, the mention of the crank breather tube/pipe. It runs through the auto advance and points cam???
I had a long screw in the centre of mine!! Something is not right as the cam will pull over the screw head.
Any insight would be appreciated.
Thanks :beer:
Roger
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clanger9
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Re: 1965 csr crank shaft.

Post by clanger9 »

There's no "pipe" on the later breathers. The breather tube is cast into the engine casing. It exits through a 5/16" hole onto the final drive sprocket (LHS rear of engine). Here is my modified breather to route it to a catch tank (because I ran mine without a chain guard and without the copper pipe it used to blow oil down the side of the bike...)
IMG_2287.jpg
There's no breather on the points side. Here's what the points side is supposed to look like:
IMG_3448.jpg
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1989 Moto Morini Dart 350
1993 Ducati 750SS
Locked