Oil,Oil,Oil

[ROZZER]

See photo of No 1 inlet port on my Z1B. New guides, valves, seals, rebore pistons, rings and it still smokes like a beagle on No 1 on start up for about 3-4 mins and I mean it really smokes.
http://i132.photobucket.com/albums/q26/ ... G_1691.jpg
Casting in inlet port is very poor (other cylinders are good castings and no probs with oil) and I wondered if anyone had experienced porosity in head castings, if so whats the remedy? I assume welding but can this be done and any recommendations on who could do it? SEP???
Have done 500 miles since rebore and hoped smoking would improve but it hasn't so off came the head today. Cylinders 2,3 & 4 all starting to form carbon ring at top and pistons crowns are dry and have carbon deposits as you would expect, cylinder No1 has no carbon ring and piston top is shiney clean and wet with oil, obviously serious oil use, exhaust valve black and gummy from oil burning. Spent serious money on this motor in recent months and I am hoping this is fixable- Please Help.

[Steve S]

Im no expert John but I would be surprised if it was due to a porous head,casting marks are usually present somewhere.My first stop would be the Number 1 piston,rings and bore,do all these check out okay nothing assembled wrong,broken or way over tolerance Keep us posted and good luck.

[Pigford]

Try sealing inlet, the fill with something (green antifreeze seems good at finding escape routes ) and see what happens. Not conclusive but easy check Then outlet. I'd bet valve stem, but as Steve S said, u gonna have to check piston, oil rings, etc Good luck & keep us posted on this one

[ROZZER]

Pistons, rings and bores all new and correct tolerance, assembly is fine nothing broken or misassembled.
Oil can only be getting into combustion chamber from the head, oil collecting in inlet port confirms this as does mucho smoke on start up that goes when warm. If oil ring say was misassembled the motor would smoke all the time. As previously reported, the casting in No 1 inlet tract is piss poor and looks like blobs of metal all around the inlet guide area with general lack of material in the whole port area (I'm surprised it passed out of the factory QC system) maybe this is a red herring but its kinda suspicious.
I suspect that there is leakage past the outside of the new guide (m/c shop guy is outstanding but anyone can make mistakes, he said that the inlets all went in fine but he had to install oversize O/D guides on all the exhaust valves, maybe No1 inlet guide hole is eliptical, good enough to get correct interference fit but allows oil past?)
I'm getting kit together to pressure test the combustion chamber and inlet port to see if I can detect leakage past the guide up to the valve bucket area. will let you know the outcome but it could be a while.
Any ideas on suitable sealants that could be used when installing a new guide cos it seems likely that a new guide will be needed again.
Thanks for the responses they are always appreciated.

[chrisNI]

John from what you say it sounds to me quite possible that oil is getting past the guide - you should give Debbens a call for an opinion there's not much on a Zed motor that hasn't passed their way before.


What a pain in the ass....

[Rich]

Leave the valve and seal in fill the spring recess up with parafin and see if it leaks through from the guide.

By No1 I assume you mean the alternator side. Is the problem worse when on sidestand than left on centrestand? Are the oil drain holes in the head blocked? Have you checked to make sure the seal is still on and Ok?

Your inlet tract doesn't look that bad, casting marks etc are usual. If you don't detect any leakthrough filling the spring recess with parafin fill the inlet tract with it and see if you can detect it coming through. Also pressurise the oil feed (stud hole) and see if you can detect air coming through from there.

[ROZZER]

Rich, Bike is always left on centre stand, oil seal was on guide (my first suspect point) oilways in head are all clear. Gonna pressurise combustion chamber/inlet tract and check for leaks around top of guide in spring recess just need to get a couple of plates made up to bolt to combustion chamber and inlet port- will let you know the outcome. I strongly suspect oil getting around the guide, as previously reported the hole could be eliptical and lets oil pass even tho' guide is good fit. If this is the case machining guide hole and fitting oversize guide should rectify.
Honestly the casting is appauling- almost looks like someone has attempted welding in the area around guide (little blobs of metal all around) the other tracts are smooth, photo doesn't really show how bad it is. Worth noting that I suspect that a valve has let go at some point in the past in cylinder No1 as combution chamber is marked, also carb slide has tiny pock marks on the motor side on this cylinder, wonder if damage occured in inlet tract as a result or am I over thinking?????

[Pigford]

John_roscoe, ur probably on the right track with past damage
Hate to say it but I'm gonna anyway

NO SMOKE WITHOUT FIRE (Sorry )

[Rich]

If the valve has hit the piston in the past it will probably have made the guide hole eliptical. Make sure the new one is bored / reamed with reference to the bucket chamber to get it back to true

[Garn 1]

From the photo, it does look serious. I'll submit what I was thinking anyway!
Before seeing photo, I thought it was simply the rings in number 1 pot being assembled upside-down. This has a dramtic affect with regarding smoking, blue smoke that will fill a room.
Worth a look!

Looking at the photo, it appears there is a leak somewhere from the main oil supply gallery in the head. I'm not sure if Rich's idea of filling the spring recess will help as (I think) there is an oil hole which flows into this recess.
RegardZ.

[Rich]

Quite right Garn - there is a drain hole which links across. you will need to block it with something John or pressurise the inlt tract and see if it comes out from there. You will probably need to seal the valve in the combustion chamber as well doing it this way.

[ROZZER]

Thanks for the comments guys, still not pressure tested area but will keep you posted. garn- rings are definately the right way up, I'm so parranoid that I'd made an assembly mistake that I've checked everything 3 times, problem is deffo from guide area.

Can heads be welded to repair if necessary? If so, any ideas where I can get this done. Failing that I'm looking for another head!

[Rich]

Try SEP or you could have a one-off guide made

[ROZZER]

Well I'm a Numpty - its official!
On checking the rings for a 4th time I found that top ring on No 1 piston was indeed upside down (in my defence the marking was almost invisible compared to all the other rings) but I am still a dick'ead.
Will it be OK to just turn the ring over and refit or would it be better to get new rings for that piston (done 500 miles on it)?

Is the fact that the ring was fitted wrong way up enough to cause the terrible smoking experienced on start up from cold, I'm not convinced 'cos how is oil getting into the inlet tract?

The problem is text book valve stem oil seal related (or loose guide) but after pressure testing inlet/combustion chamber to 45psi and putting paraffin in the valve bucket area there was no sign of leakage - the only thing I could not replicate was the expansion of the head/guide at operating temperature of the head, however I would have expected the leak to be present when cold given the amount of oil I found in the inlet tract when head was stripped? Any ideas gents, summers here and the Zed is still in bits (as is my head).

[Rich]

Give the bore a quick hone, put the ring the right way up, put engine back together and take it for a thrash - not mamby pamby running in. If you don't see a definite improvement within 100 miles you may need a new set of rings, but that one would have been skating over the oil so you may be Ok.