Please, I need help with timing and many other things...

Bob, I am 90% sure ive narrowed the prob down to a wet sump crank case issue, not top end oiling issue. I wish I could post picture right now, im not sure anyone understands the amount of oil I am talking about being thrown. This is more than smoking, it is litterally squirting oil out the tailpipe and the crankcase breather pipe. if it were just oil from the exhaust, id think major oil leak from top end. But with the oil being slung out the bottom end via breather pipe, I am pretty sure this is a bottom end wet sump issue. and if I keep starting it without fixing the problem, I am going to do some major harm...

Edit: bob, we were posting at the same time. I will do this test as suggested...

>>there was a question about whether the breather was hooked up correctly, which I am curious about, because it is just a hose that seemingly goes nowhere. It slips on a port on the backside of the timing area, then just goes downward under the bike. Not unlike my triumph. I did check it to make sure it wasnt clogged, it is not.
Im going to pull the oil pump. It has to be working inefficiently. Moving oil, but not enough causing the wet sump.<<

I know the breather that comes off the back of my 72's crankcase enters the top of my oil tank at the front and then another line comes out of the tank and I've exited it to the atmosphere off to the side below the bike.
It originally terminated into the filter box.
Not sure about the 71 termination. Maybe just as you have it, however running mine through oil tank allows any oil mist to be captured.

When you are working with your pump try as best you can to assess whether the oil holes in case are clear in case some of the debris you described from its earlier blow up is still in there. There are threads on this site that decsribe lapping in the face of the pump.

I suppose you don't know what caused the original seizure of the motor but it could be related to the pump and oil supply.

Good luck.

Ok, I am back in PA at my computer so I can post some pics about what troubles I was talking about. First, here is a photo from the first time she started. Please note that smoke is not a kick-ass burn out, that is coming from my exhaust.


Next, here is a picture of the alley way behind the garage. Please note all the oil slicks the bike caused. These oil patches are from when the bike was sitting stationary and running, probably for no more than a minute in each instance. Big patches are from oil misting out the tailpipe. The dots on the road are from dripping from the crankcase breather.


Here is just a pic of the bike, because it looks so sweet.


Here is a pic of an exhaust joint at the 2 into 1, showing oil coming out down there.


So yes, I just went ahead and pulled the oil pump, I got to thinking I pulled gasket material out of the filter plug on the bottom of the crank, maybe it got into my oil pump. Sure enough, there was gasketing material up in there. But I am not sure enough to cause wet sumping that badly. I used a mechanics pick to try to poke up in the holes to make sure nothing could be clogged up there, didn't detect anything. Cleaned up the oil pump really good, it really seemed fine. Could feel good suction on my fingers covering the holes when turning the worm gear. However, it wasn't until AFTER reassembly that I got the bright idea that I should have used an air compressor to try to double check the holes and clear any potential clogs. Does anyone know off hand which of the holes in the case/oil pump would be the one designated to suck oil up from the sump and keep it from wet sumping? If this doesn't work, I am going back in there to triple check the holes and lines.

As much as I wanted to try starting again after reassembly, it was getting too late and we were running out of 20w50. So there is another week or two before I can work on her again for all your expert opinions and advice on this issue.

Here is another picture I wanted to present and ask a question about. This is the pic from inside my timing cover, up by where my hand is, top left inside the case, does that look normal to you guys? In the 'norton book' I bought, it doesn't show anything there. I leafed thru all the diagrams and photos and it didn't show anything there. All the gasketing material I found during re-clean and oil pump removal was blue, which I didn't use. I reassembled with red gasket when needed. That plate and breather up there was caked with blue gasketing material (previous owner, I guess) Is there something else that would have gone there too? Because that seems like an awful big hole to cut into that case, just for a small tube to come out to atmosphere. I mean, that round plate is like 3-4 inches across, and ultimately, there is just a 1/2 in hole coming out with a rubber tube. Also, if you are looking at the round plate, and come down to about 4 o'clock, there are two thread holes in the case, like something is supposed to mount there. Is there something else that is supposed to be in there? It didn't appear to be addressed in my book.


Here is a picture from the back side.

Your are right we'd all assume you were doing a burn out in joy, ugh not burning lubricant away.

Oil pump face has a round and oval port, smaller port pushes oil into engine and larger oval pushes out to tank.

About only two places in engine that might have enough paper gasket to pollute as you describe would be the time side cover and a cylinder base gasket. Blue RTV is famous for excess to leave the area and clog, but I'd think you could tell RTV for paper clutter. Its possible the rocker cover gaskets got sucked into the valve train, chewed up and not quite swallowed, so some still clogging the tiny and long and sinuous intake oil drain that spits out in TS area above the oil pump. That would flood the intake valve guides which see suction on intake stroke and smoke like a mosquito fogger. Intake valve stems should have seals on them to help prevent this even w/o a plugged drain. Its also possible the intake rocker spindle on one side was placed in - as obvious designed - with the flat cut over oil feed hole, which flows too much with a Commando pump so the flat should face out to block as much oil as possible, crazy as that may read.

Someone has kinda crudely made an improved breather hose vent on the old magneto-plate drive area, but looks like can be cleaned up and continued to use as many of us put our breather exits there. That hose path is where the oneway PCV valves get placed to help the oil stay inside lower pressure than outside.

That much oil will likely coked up the chamber so might lift head and clean it up while plurging the rock drain through the cast iron cylinder. Bet a bunch of blue crap is in bottom of oil tank and maybe crank sludge trap.
I'm too familiar with your level of despair, I mean repair, so offer my condolences on stealing time to get her right, which can take who knows how long. Your Cdo has a neat presence of vintage brute and speed, besides marking its territory like a hound dog lifting its leg to ...

You might want to read a few breather threads. Usually when it's vented out the magneto area, a PCV is there and the timed breather line off the left side of the engine is just plugged with a bolt. I'm sure that won't solve your problem, but it sounds like you're on the track. Must be something clogged. I'd go over the internal oil lines, even if you have to pull the head and barrel.

Dave
69S

Wow that's a lot of smoke, Your somehow sucking oil into the cylinders. Really only two things I can really believe are happening, 1) intake seals 2) an issue with the rings, now that you have the timing cover off I would blow through the pick up hole, Then lap the pump. After seeing the amount of smoke you have I really don't think this is a breather issue, Or maybe it's an oil pickup issue and the crank is full of oil. And that's why it's blowing it out the breather. But you should do as said above and check the easy things first, The rocker shafts and then the intake seals. Then next I would say check the rings, That's a hell of a lot of smoke. :?

the sparx ignition is junk and not to be trusted. I had 3 fail under warranty after the 3rd failure I went with pazon. The sparx trigger could not handle the heat all 3 failed within 600 miles. I have had the pazon for about 7500 miles and so far not a problem.
Doxford 69 750 roadster.

Quick question for those who have lapped the oil pump before... I read articles here and in my norton book on how yo do it, so that makes sense, but curious about whether there is supposed to be a gasket between the pump and the timing cover upon reassembly? When I disassembled, there was a thick paper gasket as well as silicone on the pump. Maybe that wasnt supposed to be there? (i didnt do it, pouting silicone in there sounds dangerous to me... I already pulled excess silicone out of every nook and cranny, sloppy job by previous owner I guess)

The thin gasket under pump ain't to seal there so much as space it for the nipple crush seal. Do not put sillycon in there is will crush and decay away. Here's collection of oil pump sealing hassle details.

The Mark III seal is thinner than the other. It has a small taper then flattens out, whereas the other has kind of a dome.

Here is what my factory manuel says Section C30 / 11 third paragraph ...Very late engines use a joint gasket between the oil pump and crankcase joint faces and where a joint washer is used at this point, under no circumstances should the conical rubber seal between the oil pump and timing cover be equiped with packing shims....

Para 13, Fit a new conical rubber oil seal part number NMT272 on the oil pump outlet stub and dispense with any shims which may been fitted between the seal and pump body at the time of dismantling. Over compression of the seal will render it unfit for further use.

It appears part of the shimming process is the paper gasket behind the oil pump, and when used with the proper seal and stub outlet, should get the proper clearances without shims.

The '75 and later 850 MkIII had a different seal that didn't require shims. All other Commandos both 750 and 850 used the conical seal and required checking to make sure there is compression. The amount of compression is just enough to make a seal, don't completely flatten the seal. The doubt I have is .020" is a lot of shim and I haven't needed shims in the past. Better to check again and waste the seals. Then on to the blown crankshaft seal in the primary.

Just one more word of caution about eliminating gaskets: the oil pump gasket is .007" thick, so eliminating it will reduce the compression on the oil pump seal by this same amount. This could mean the difference between adding shims or not on the older twin chain motors. Or, possibly an ineffective seal if shims aren't used to make up the gap.

There are 4 things to consider in seal fit of pump to TS cover. oil pump/crankcase wispy gasket, shim under pump nipple, thickness of pump nipple and thickness of TS cover gasket. Here's the recommended combo for all Norton twins below.

Walridge Motors catalog:

Note - Later, thicker Commando type timing cover gasket [06-1092] is recommended for use on all 500-850 twins, but MUST be used in conjunction with oil pump gasket 06-2447 to ensure correct positioning of the oil pump vs timing cover.
Timing Cover all yrs, p/n 06-1092
Oil Pump all yrs, p/n 06-2447
Oil Junction block all yrs p/n 03-2044

Click to expand...

My bike will smoke just like that when it wet sumps after sitting a few weeks. Right side.

Last time it did it I was in the garage with the big door open and it was like a freakin' cloud which hung in the air for a long time.

Hello group, so I found time to work on the bike this weekend and have an update and couple questions. First, before taking the motor apart I decided to triple check the oil pump. The bike is wet sumping in my opinion, so I worked on the oil pump and lines. I followed the inductions on re-upping the oil pump, took it apart and cleaned it and planed it, got it tight again. Blew compressed air thru ports and holes and lines to make sure nothing was clogged. Reassembeled and started it, she smoked much less but still same problem. Removed oil filler cap and watched the oil return to tank. Now im starting to lean toward the rings, but my dad swears it is the oil pump not vacating the sump adequately. New pump costs $400 plus and that is a tough pill to swallow if the old man is wrong. Does anyone on here know what sort of oil pressure should be on the return side of the oil pump? Is there a way to check the oil pump working efficientlh enough? I mean, he could be right and it just isnt sucking oil fast enough or hard enough and allowing oil to build up in the sump. But man, the oil pump seemed good, moved oil thru it whilst turning by hand when I had it off the bike. Oil was returning to the bottle. But enough? Any insigbt would be appreciated. The bike starts, idles, runs pretty good considering the fire is obviously being roached by oil, im having trouble wrapling my brain around a bike running this good if my rings arent right/didnt seat. but I also cant wrap my brain around a bad oil pump that seems to be good and tight and moving oil.

At this point let's assume the oil pump is ok. Can you get a compression gauge and do a cylinder check and report back? The next step is a leak down test to determine if your rings or your valve guides may be passing oil into the combustion chambers. These are very easy tests to run and tell a lot.

Your motor may simply be in need of an rebuild, be it rezoned and new rings, along with valves and guide work.
Any idea when or if this has ever been done?

Yes, the bike was rebuilt by me slowly over the last two years. It is .020 over with new rings and all top end as well. After I got it running a few weeks ago and i first had this problem I checked compression and it was 135psi, so I figured pump. I did check compression yesterday and it was 105psi, which is low, but bike was hot (should check cold) and cylinders obviously filled with oil. Still squirting oil out my crankcase breather too. If valves, wouldn't be doing the breather thing. And oil is vacating thru both cylinders, not just one. If it were just one, id say compression ring good oil ring is bad on that cylinder. But both cylinders?

squirting oil out your crankcase breather?

can you be more specific?

how is your breathing plumbed now? crankcase breather tube goes where and then where and then where?

Also, assuming you are draining any oil from the sump before starting cold motor, does it smoke right away and continue, and smoke coming out both pipes?

Yes, oil mists out my exhaust and dribbles out the breather. Not just a little dribble like, this is going to make my bike dirty, but a steady dribble that leaves a puddle if the bike sits still. The breather doesnt go anywhere specific, it comes out the crankcase on the left side and I have it routed back under the bike and comes out down by the chain. And yes, I drain the sump before restarting. I know where you are going with this, so i'll say that at this point there is enough oil in my cylinders that it smokes even at start up, but that doesnt mean anything because there is already oil in there. But I do believe the smoking gets worse over time. Lastly, it is two into one exhaust, but I have pulled the plugs enough to say definitely both sides are getting oil in them. I pull them out and they are both wet with oil.

That breather should really go back into the oil tank, it won't hurt anything doing that and you'll save some oil and you don't have to drain the sump. Does your oil tank have a breather to the air somewhere or have you blocked it off? You really don't want pressure building up in the oil tank. I checked my crank breather off and in about 2 minutes from a cold start, it pumps out a good oz of oil and it keeps coming although slower later. But that's not your smoking problem. I'd do as many tests for compression, rings, etc. to see if you can figure it out, block off the line to the head for a minute or 2, it won't hurt and see if it helps the smoking. With oil fouling the plugs like that, I just don't know, but for sure something's wrong and I doubt the oil pump. It wouldn't hurt to route the crank and oil tank breathers correctly.

Actually the other day I forgot to tighten the breather to oil tank line after I had it off, it came off when I started it after a few days and boy, it pumped out about a pint all over the left side and on the ground real quick. Most of the oil is out of my tank and into the crank in about 2 days.

Dave
69S

Without reading all the other posts on the subject - did you replace the O ring seals on the inlet valves? Did you rotate the rocker shafts to the correct alignment so that the cut away faces away from the head? Did you check the valve guides for firmness in the head? This problem sounds like over oiling in the top end, nothing to do with the return capacity of the pump.

Mick

Yes ,too much oily stuff to the head -valve things. Disable the rocker feed to find out, don't worry, it will run a long long time before damage.

Were you able to confirm the oil to the intake valve box is draining down through the the hole through the head and barrel?
Sealant on base gasket may have plugged it.
If so box will fill with oil and have good chance to be pulled through guides.
If blocking oil feed to head stops smoking this could be whats happening or rocker shafts not rotated with flat sides pointing outward from engine.

Drain sump.
Start bike and if it takes a couple of minutes before smoke gets bad maybe is wet sumping.
Then drain sump again and see if you have more than maybe half a cup of oil. If wet sumping maybe a couple of cups plus oi level in tank should be down noticibly.

Thanks for the additional input. I will pull the top end oil feed lines next to see if it is top end issue. But id hate to think it was both sides... The top end is all new and I had a machine shop do the work, but that doesn't mean it was right, they could have done it wrong. Also, I can't recall about the rocker shaft alignment like a couple people posted... It has been over a year since I put the motor back together, but I remember the assembly pretty well, but have no recollection about anything special about the rocker shafts. I'm not sure it said anything in my 'norton book' about that (I'd remember reading it), so I am going to guess I put them in without any specific form.