Japan Meets Britain

[Vince Lupo]

I would have thought so too, initially, but it's definitely an oil leak (maybe I need to show more of the mess!). Plus, my oil level was down, so I'm thinking it's either the countershaft sprocket seal, the seal arrangement that NOVA made for the kickstart shaft area, or the clutch rod seal. My guess is the sprocket, judging by the cleanliness of the chain (and after having ridden over 550 miles since I last lubed the chain and it still looks clean and wet), but I guess anything down in that area could cause it. John's busy for the next few weeks, so I'll have to wait to see what's going on behind that cover. I just hope that there isn't anything else going on beyond it being a bad seal to cause oil to be leaking out of that area.

[LOUD MOUSE]

Where did ya install the top vent tube?. ........lm

I would have thought so too, initially, but it's definitely an oil leak (maybe I need to show more of the mess!). Plus, my oil level was down, so I'm thinking it's either the countershaft sprocket seal, the seal arrangement that NOVA made for the kickstart shaft area, or the clutch rod seal. My guess is the sprocket, judging by the cleanliness of the chain (and after having ridden over 550 miles since I last lubed the chain and it still looks clean and wet), but I guess anything down in that area could cause it. John's busy for the next few weeks, so I'll have to wait to see what's going on behind that cover. I just hope that there isn't anything else going on beyond it being a bad seal to cause oil to be leaking out of that area.

[GORDON BROWN]

Vince
If the leak is from the clutch push rod seal and is not obviously a seal problem. Try twisting the pushrod within the gear shaft without the seal and check for undue resistance, if there is remove the rod and check for marks about half way along.
I have had two nova race boxes 1 CB72/77, 1 350K and the centre hole through the g/box shaft on both look like they have been drilled eccentric from both ends leaving a offset ? ridge in the centre.
Once the shaft was turning it was knocking the rod in a eccentric fashion and causing a leak at the seal. Of course when the bike has stopped so does the leak and it was a pig to find what was wrong.
I hope this all makes sense and if this is the problem and I hope it's not, my solution was to make a push rod with a reduced centre section and it solved the problem.
Keep up the good work.

Gordon
SAFOJ

[Vince Lupo]

Thanks for the suggestion, Gordon. I won't really know what's going on until John checks it all out, which will likely be in a couple of weeks. As far as the top vent tube goes, it's located where it's supposed to be, and there isn't any oil located in the 'trap'. As well, the tube isn't kinked or anything like that, so I don't really think that's it's a factor in this issue.

Right now I'm in a holding pattern, but I'll keep you guys updated once John has a look.....

[Vince Lupo]

Vince
If the leak is from the clutch push rod seal and is not obviously a seal problem. Try twisting the pushrod within the gear shaft without the seal and check for undue resistance, if there is remove the rod and check for marks about half way along.
I have had two nova race boxes 1 CB72/77, 1 350K and the centre hole through the g/box shaft on both look like they have been drilled eccentric from both ends leaving a offset ? ridge in the centre.
Once the shaft was turning it was knocking the rod in a eccentric fashion and causing a leak at the seal. Of course when the bike has stopped so does the leak and it was a pig to find what was wrong.
I hope this all makes sense and if this is the problem and I hope it's not, my solution was to make a push rod with a reduced centre section and it solved the problem.
Keep up the good work.

Gordon
SAFOJ

Just heard back from John, and that indeed is the problem.

[GORDON BROWN]

Vince
Not so good, but at least, hopefully that's it and slightly reducing the pushrod dia. appears to do the trick OK.
The only thing my one being a race bike has not done a lot of actual mileage, though perhaps a few more RPM !

Gordon

SAFOJ

[Spargett]

Vince, let us know how you go about fixing the issue.