I THINK I've put my OIL SCRAPER RING IN UPSIDE DOWN

ANLAF

ANLAF

XS650 Guru
Messages
1,526
Reaction score
7
Points
38
Location
Anglezarke, Lancashire, UK
I am going to strip-down the engine again tomorrow. I rebuilt the top end last week with new cylinder, pistons, and rings. The Right cylinder is behaving fine, but the blue-grey smoke form the left is a problem

5twins happened to mention putting the piston rings in the right way. I wondered if he meant there was a particular way up they had to be.

I see there are numbers and a letter on one side of the oil scraper ring (25, and a letter R), and on the other side there is a definite lip. This must go in a certain way. If so, I may have put my oil scraper ring in upside down on the troublesome left cylinder - oil is not being scraped away as it should.

QUESTION
Which way up should the oil scraper go?

Anlaf
 
The manual is a wonderful thing. Haynes page 40, section 21 says the compression rings and the scraper rings are both marked with an R (and number if it is oversize) and this side should always face upwards.

Ah! I did not check. Looks like I should have looked in the manual before fitting the rings. I only have myself to blame, but I have learnt form that experience.

Anlaf
 
I installed my rings today, checked the old ones, and they had the number and letters facing up, so I did the same. I didn't however, see any numbers or letters on the oil scrapers, and they seemed the same both sides, so I just installed them. I guess I will be redoing that stage as well, and check a bit better! Lucky for me, I haven't finished my top end build yet!

Sorry to hear you are having so many problems with your build mate, hang in there!!
 
Fellers - oh! yes, oh! yes, I have indeed got the compression ring and the oil scraper ring in upside down.

It's a great sense of relief to know I've found the fault. Well, here we go, putting it all back together again - carefully following the ring gap orientation, of course. thanks for pointing me to various diagrams.

Anlaf
 
haha

Anlaf I feel you man. I had my whole engine put together and then noticed someones thread saying make sure the pistons are facing forward and I remembered not knowing I was supposed to do that so I had to tear the top end down and sure enough they were in backwards. Good thing I never started the engine prior to switching them around
 
Anlaf is that engine being rebuilt with new oversized rings and a rebore and hone ?

I'd be surprised if the left cylinder smokes just due to the oil rings being upside down ?

I shouldn't have thought any of the rings had had a chance to bed in properly.!

The other thing that strikes me as odd is why is it only the same cylinder effected as the last time ? If having the rings upside down was such an issue I would expect it to smoke equally from both cylinders.........:wink2:

I suspect there is something else going on there other than the oil rings being upside down. I should think that the majority of rings get installed upside down and the pistons back to front with diy rebuilds.


I suppose the engineering shop did resurface both the head and the block ? and checked the bores for ovality.
Did you check both sides of the head gasket for any leakage from the centre cam chain cavity to one of the cylinders ?
 
I didn't mess about this time, Peanut, I got new cylinder from Heiden matched to new pistons and rings.

Searching the net for things related to inverted rings it is generally 'stand back and watch the oil burn.

Nearly finished, just having a cup of tea, then cam chain tensioner, valves, timing, carbs - start up.

Anlaf
 
ANLAF said:
I didn't mess about this time, Peanut, I got new cylinder from Heiden matched to new pistons and rings.



Anlaf
Click to expand...

thats the mutts nuts !:D:thumbsup:

You must be getting pretty slick at doing this by now :wink2: Reckon you should consider offering new top ends :laugh:

Wish you all the luck in the World ...looking forward to seeing that first video of its maiden test run:thumbsup:
 
Thanks Peanut, but, Oh! No - just started the beast. On choke, fine, off choke fine. Thirty seconds later, puffs of the white smoke from the left cylinder exhaust. Don't panic, I thought, give it a little run. I was on one cylinder by the en d of the street. Came back.

Oh-blinkin'-no!

Right cylinder plug fine, left plug signs of oil.

What next, eh? I am fed up.

Anlaf
 
^I'd be pullin my hair out now.

Before you even think about it anymore I suggest you do a compression test. That will point you toward rings/cylinders/pistons, or valves and guides. Did you measure the ring gaps while it was apart this time? And are you 100% sure you have the right rings? If the head is off you can pour gas into the combustion chambers to see if the valves leak.
 
yeah I agree ...a compression test or better still leakdown test.

My feeling is a head gasket leak between the left cylinder and the centre cam chain cavity thingamebobby whatever its called :D

To create the amount of oil and smoke you are talking about its not going to be the rings or ring gaps !

The left piston must be sucking oil into the cylinder when its on its downward travel drawing in fuel but you would expect excess crankcase pressure if that were the case.?
 
Fellers, here's an update:

When I started up with choke, fine, then some puffs of smoke then the white smoke seemed to stop as I rode off.

Then it started spluttering and (I thought)running on one cylinder. The it stopped. Would not start again. I pushed it home - that's when I wrote the above post.

Now I've just gone back to the bike - could having no petrol have something to do with it? Yes, no petrol. I shook the bike to get the last drops in the carbs - started and no smoke.

Tomorrow - fuel and try to run it. The white puffs of smoke may well have been burning off some residual.

Anlaf
 

Similar threads

cbertels
Oil and smoke in right-side exhaust
Replies
18
Views
661
Grimly
Grimly
lumbee
Leaky base gasket
Replies
11
Views
1K
Oldnwiser
O
Wingedwheel
77D assessment.
2 3 4
Replies
60
Views
4K
Wingedwheel
Wingedwheel
G
Right side ticking
Replies
2
Views
704
Gfoer1022
G
townesvanzandt
Help! Bike bogging down bad out of nowhere - ignition coil? carbs?
Replies
7
Views
854
RustiePyles
RustiePyles
Back
Top