Horizons Unlimited - The HUBB

Horizons Unlimited - The HUBB (https://www.horizonsunlimited.com/hubb/)
-   Yamaha Tech (https://www.horizonsunlimited.com/hubb/yamaha-tech/)
-   -   have you ever seen rings like these (https://www.horizonsunlimited.com/hubb/yamaha-tech/have-you-ever-seen-rings-47686)

chucky55 13 Jan 2010 22:55

have you ever seen rings like these
 
3 Attachment(s)
Hi all,
Like to share some info. Bought a 1985 49L xt600(35000K) 2 years ago. I could kick start without de-comp, I knew the rings were gone, but the bike went ok but down on power so I kept riding. 2 weeks ago cam chain jumped while trying to start and hit valves. no valve damage. Stripped down to find these rings. I do not know how this motor was still running before cam jump.
First pic shows top ring in barrel with 7mm gap :censored:

second pic is second ring in barrel with 5mm gap :censored:

Third pic is bottom oil ring sharpened to a needle point and starting to enter barrel to piston gap :frown:

Is the xt600 a legend or what???

So, barrel is original bore but worn, rebore and new piston on the way.

I'll keep you posted, but these rings are sad.:funmeterno:

Cheers from Oz

oldbmw 14 Jan 2010 16:47

If I were you I would drain the crankcase looking for metal. Clean the case and cycle new oil through the system. Check that you have a good flow and all bearings run smooth without play. Check also the valve guide fit and that the guides show no sign of overheating.
I have never seen rings that bad before and I grew up using bikes all through the sixties and I expect there to be an underlying reason for their failure. Find and fix this before running the new parts. The fact the cam chain jumped also points to bad maintenance. If it were an old Brit bike, people would cite this as an example of crap design, wheras in truth it is probably the fault of its previous owner.

In view of this carefully check over all safety critical parts such as wheel spindles, head bearings etc.

I had intended to buy an old Triumph, but in the end bought a fairly new Enfield simply to be sure of no PO problems. Not entirely successful as I have since discovered he fitted a bigger gearbox sprocket :(

Pigford 14 Jan 2010 18:47

Wowwww........... Yessiree... sure has ample "end gap"

Just goes to show these older bike keep on chugging along!

chucky55 14 Jan 2010 21:20

Yes they are sad
 
Hi oldbmw, & pidgford,

I have already started to clean the bottom end, just petrol wash so far with air assist wash this weekend. When I boufgt the bike the air filter was non existent, I did oil change and new genuine air filter. As the bike had run for some time with no air filter and the state of the rings, I believe a lot of grit passed the rings into the bottom end and stayed in the oil left in the case.
So bearings on the bottom end feel fine. Grit in oil will kill morse chains so new one on the way.

When I took the barrel and rings to the bike shop last night, they could not believe that the bike ran with the ring gap!!!

All critical parts of bike are being checked.

I'll keep you posted.

Cheers from Oz.

britch 14 Jan 2010 22:11

Interesting pictures cheers,
just out of curiosity, was it burning lots of oil ?

chucky55 15 Jan 2010 00:25

Burning oil???
 
Hi Britch,ow much. Maybe

yeah it was using oil, as I don't ride hundreds of K's on this one I cant say how much with confidence. just a paddock basher, just couple hours wekend, maybe a pint/100klm.

Now I'm rebuilding, I think I'll keep this legend and put it on the road.

Still a lot of hard yakka to clean out the bottom end, but what else could I do this weekend except ride.

Cheers from Oz.

1D Pilot 16 Jan 2010 05:34

have you ever seen rings like these?

NO I have never seen such worn rings and I have seen a lot of them.

Thanks for the pictures. they are one for the record books.


All times are GMT +1. The time now is 11:51.


vB.Sponsors