Wos dat den?

[warren3200gt]

Stripping the paint from J2 frame. There's no frame number on the headstock only madeinjapankhi stamped vertically but it does have 87 stamped on the top cradle cross brace.
Only stripped the head stock so far so am I going to find the frame number else where?

[Gus]

Could be a replacement frame.

Gus

[warren3200gt]

Kinda guessed that Gus from the lack of frame number, I was more intrigued by the 87 stamp. Maybe I've got number 87 out of 100 limited edition little known super special worth a fortune race special
Or maybe year of re frame?

[Al]

Nearly, quite a few of the brackets have numbers stamped on them. They're for location and orientation (number faces outward) for a sort of welding by numbers approach to assembly by anyone who can point and shoot a MIG welder..
If it has the original swingarm in it, does it have any damage immediately behind where the front sprocket is? It would be on the cross tube on LHS if it does!
AL

[warren3200gt]

So "weld by numbers" primary school special.
Not Checked the swinger yet but didn't notice any marks at the removal time.
What's that all about Al?

[Al]

The front sprockets used to fall off and jam with the chain inbetween the swingarm and frame cross tube that carries the brackets for the centre stand. It would bend the cross tube and puncture the swingarm particularly if at high speed. I was trying to think why the frame might have been replaced by a new genuine article and that was what i came up with. Mine was one such bike and it may have been beyond the warranty period because the frame is still bent there and the swingarm was more or less destroyed but still in place. Its also been over on the RHS and these two effects may be from the same event but i cant really say.
AL

[warren3200gt]

Better weld the sprocket on then just gotta find a sprocket with a number on it and a primary school kid to weld it on!
I'll have a look at the swinger tomorrow as the tank had some badly repaired dents in it on the right hand side.

[Al]

Better weld the sprocket on then just gotta find a sprocket with a number on it and a primary school kid to weld it on!

In the immediate post war period in Italy all the men had run away but the motor industry still carried on. They used to employ children after school for sweeties' money to come in and weld car bodies / do basic leg work jobs.
The exterior panels (skilled work) were utterly sublime and you wont find better welding or panel skills. The chassis's and structure (unskilled jig welding) were utterly appaling, you'd be hard pressed to find worse.
I know we are talking about the eighties but in the white heat of burgeoning world orders for their products, could you forgive anyone for trying anything to get their product to market?

AL

[Al]

[warren3200gt]

7. Weld the sprocket on the shaft.

Seriously though, what's the fix? Just remove the washer and then re torque the bolt?

[Al]

That diagram you posted above has the fix within it. It would be a later version of this circulated in 1981.

[Al]

Have you got a centre punch mark to the left of the engine number??
AL

[warren3200gt]

Oh, that's handy mine has the fix applied. Must check the eng number to see if it's been centre punched.