Jota pumping oil out of c/case breather

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globaljed

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After a fast blast I had a lot of oil (well it looked a lot) over the back of the bike.

Bike is a 1976 Jota, 7C cams, Mikuni RS36 carbs, Bosch CDI etc and I was revving over 9k but this hasn't happened before!

Any thoughts / comments.

Thanks
 
you hadn't just topped it up by any chance?

a little hot oil goes a long way, try putting a catch bottle on it, to see just how much it is spitting out. is it smoking?
 
Overfilled with oil?
Rings worn?

35 year old bike and 9,000rpm...
 
My bike did that when the rubber ball in the breather got stuck.
I assumed I'd broken a ring, lugged the engine out and stripped the top end down only to find nothing wrong doh!
 
you need to get hold of a Leak Down Tester and use that to find out what is wrong
could be rings have failed, bent conrod, problem with engine breather, cam cover leak, probably couple of other suspects

your running 7C cams and Mikuni RS36 carbs and you still have the standard Bosch CDI system installed  :o
damn, I generally advise people to change the ignition first
 
Jed,
Over 9k...count yourself lucky the back of the bike wasn't covered in pistons! ;)
had this problem when i bought my Jota back in 2002...worn out pistons and bores , sadly.No magic cures, ball in breather etc.
and be careful til its fixed, eh? That oil goes all over the rear tyre, so you are in life threatening territory, frankly....get it sorted for your own /familys sake. Here endeth the lecture :D
Nick7
 
Tough old dogs the early Jotas, definately the best! (just waiting for Red to nuke us now ha ha)
 
"35 year old bike and 9,000rpm..." - always said the earlier "proper" jotas were the best - Regards - Phil
Click to expand...

Oh yes! Had both early and late - the 1976 one was brilliant, the 1981 was not...

Pete
 
rings have gone, thats it,its simple,do a compression test there is no other answer ::) ::) ::) ::) ::) ::) ::)unless you take the ball out of the breather throw it on the floor if it bounces back up ,its the ball
 
Jed, You were thrashing her...and that's your prerogative...but the crankcase pressure was building
and has to go somewhere. My previous Jota did that once on a ride from the Cat and Fiddle when I gave her the beans..but I didn't redline her.

Try riding within the redline or at least don't exceed it and see if it's still blowing. If she is..check your plug condition...the little ball in the breather deteriorates with time...For gawds sake don't start the investigation backwards by stripping the engine....look for the simple solution first.

hope you solve it.

joe

ps buy an MV Agusta F4  9000 rpm is for babies there  ;)
 
Well, lets hope the breather ball dreamers are right ,eh? Don't get your hopes up though....rings? Could be but my guess is pistons too (it was for me). Guess you need to listen to Red about the leakdown test  first..don't know which pistons Keith N recommends, but depending where you are, talk to the right people before choosing(and re-boring)
And as the redline is wrongly marked on the rev counter(6.5 k start I think), ignore that and stay under 8k maybe..if you don't you will be shopping for new rods etc too..carillos sound a good option .
After years of trying to stop oil either coming out of the breather or burning through the engine, my Jota doesn't seem to use a drop or smoke or blow oil out..weird..wouldn't have bought 25 l of morris 20/50 if had sorted this earlier :D
Nick7
 
Fair enough...I tried the additional breather fitment route..think Phil mentioned it, from a Morini...no joy there, obviously the problem was more serious in my case (not what you would expect when the DPO had  had the thing rebuilt by one of our esteemed dealerships just 500 miles before...anyway, that's history now). In my (embittered,plainly) experience, prepare for the costly solution, and if it isn't that you will be pleasantly quids in for a teeny rubber ball only ;)
Nick7
 
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