Comet Oil Loss after 100mile run

Gene Nehring

Well Known and Active Forum User
VOC Member
Hi Guys,

Went on a run a couple of weekends ago to meet the Vancouver members of the VOC.

Upon getting to the meet my Series C Comet dumped a fair amount of oil. I was talking to the guys there and seemed like it could be residual oil being blown out the breather. The oil level went from above the bridge to below in the oil tank.

It seems to me that the oil came from the primary chain case area and not the breather. I have ridden the bike since on shorter rides to my local village and back 30km or so one way. I have seen not a drop.

I am trying to wrap my head around where the oil might have come from. One idea I had was that it was wet sumping?

Any ideas greatly received.

Cheers,

Eugene.
 

ogrilp400

Well Known and Active Forum User
Non-VOC Member
G'day Eugene,
This is not an unusual problem on Comets mainly because there isn't an oil seal on the crank between the crankcase and the primary and no oil seal on the gearbox main shaft where it enters the back of the primary case. Consequently oil is moved from the crank case into the primary case where it over fills and comes out of the back of the primary case. This problem was covered on this forum just recently and the solution is to fit a seal to the crank case behind the main shaft sprocket. This stops oil migrating into the primary chain case. Then fit a rudimentary seal behind the clutch.
 

Gene Nehring

Well Known and Active Forum User
VOC Member
G'day to you too... I am originally from NZ!

Could you link me to the other thread please. I will look at doing the fix in my winter your summer.

Thanks for the reply. Nice to know that I was on the right path.
 

Howard

Well Known and Active Forum User
VOC Member
You're not alone, I've got to do the same job this Winter - I think the mod's described in Know Thy Beast.

H
 

Martyn Goodwin

Well Known and Active Forum User
Non-VOC Member
You're not alone, I've got to do the same job this Winter - I think the mod's described in Know Thy Beast.

H

Recently a fix for Comets to both the primary case /main bearing oil seal AND the drive chain/burman clutch oil seal were fully documented in 998.

Send me a PM with your "real" email address and I will send u copies of the 2 articles.

Martyn
 

manxman

Forum User
Non-VOC Member
Recently a fix for Comets to both the primary case /main bearing oil seal AND the drive chain/burman clutch oil seal were fully documented in 998.

Send me a PM with your "real" email address and I will send u copies of the 2 articles.

Martyn

Martyn, I found this older thread using the search function. Would you be able to send me copies of these two articles as well? Experiencing the same issues with my Comet and I don’t have a copy of 998...

Happy to PM with my email address if that’s easiest.

Many thanks!!
 

Bill Thomas

Well Known and Active Forum User
VOC Member
I wonder if on the first post, He was trying to keep up with some Twins ?.
I remember going from London to the Midlands , To see Don And Marion Alexander,
My Comet has never gone so well,
I had no need to go fast but I was just in the zone !.
It was flying and the MPG was good too, It had a T.T. Carb' on at the time,
When I got to Don's It and me were covered in oil, I had to leave it in the street while I went in for Dinner !.
After cleaning it up a bit , I came home a bit slower in case there was a fault, Kept looking down ,
But no trouble !!,
Never had any trouble since and that was many years ago, I have never fitted a crank seal, Don't like the idea.
 
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