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

Westernjesus , a Norton head is an over-oiled thing . When reassembling rocker shafts remember you want to impede oil flow so the smooth part of the shaft goes against the tiny drilled passage that comes from the rocker feed. That cutaway gallery in the shaft goes towards the valves-rockers. Starve the head of oil by stopping the rocker feed ,there is a thread on this somewhere methinks. Run the motor or drive till things clear up and your smokin' stops. Then you know the problem is with the head ,understand? You will not damage any head components doing this test as residual oil will get you through it. Remember that really early motors had exposed valves and springs and the operators would press a little plunger thing to supply a little oil at very unspecified intervals, perhaps they used The Force to decide when.

Update: re-ran compression check, compression way down to 105 and 90. Screw it, I am going into the motor again, not leaving it to chance, so I got 40 over pistons and rings. But the question remains, was bleed past the rings the cause, or is this the effect of it wet sumping and roaching my 20 over pistons? Chicken or egg? Remember, I had 135 on each jug aftdr my build. Does anyone have any suggestions to confirm oil flow from the sump, lest I punch it, then have this happen AGAIN?!?!?!

westernjesus said:

Update: re-ran compression check, compression way down to 105 and 90. Screw it, I am going into the motor again, not leaving it to chance, so I got 40 over pistons and rings. But the question remains, was bleed past the rings the cause, or is this the effect of it wet sumping and roaching my 20 over pistons? Chicken or egg? Remember, I had 135 on each jug aftdr my build. Does anyone have any suggestions to confirm oil flow from the sump, lest I punch it, then have this happen AGAIN?!?!?!

Click to expand...

Before you go into the motor again you need to re-read the suggestions here and figure out the over-oiling of the head.

As was suggested:

1. Block the oil to the head and see if it makes a difference. Have you pulled the valve covers and seen what is going on in there?
2. You can pull the rocker shafts without pulling the engine. With the right tools it's not a hard job.
3. Once you have the oiling sorted you can re-check the compression and worry about that. You haven't ran the engine long enough to bed the rings anyways.

If oil is coming back to the oil tank, the pump is probably not the problem.

Dave, perhaps I wasted a couple bills in a fit of frustration, I already bought the pistons. I haven't been to the bike since the previous posts, my bike is in MD a couple hours away and my father re-checked the compression for me. When he told me the compression indeed was gone, I just bought them. I took everyone's hints about top end to heart, but haven't had an opportunity to check your suggestions. While the oil problem may end up being top end after all, I still think there is a problem with the rings.
This 'working on the bike every other weekend' thing and 'never getting anything done' and 'bike not on the road' has worn me too thin. I am putting this bike on the road this summer, I am going to get the bike done right, and I will not have a problem with it again anytime soon.
I am going to check all the things that everyone on here suggested, I have learned a lot from all you guys, but I am going back into that motor. I am going to alleviate all doubts from my mind. I worry about that gasketing material I found, I worry if that could be sitting down in the sump to get picked up later. I worry if it is blocking the drain down from the top end. I worry about those rings and the deep loss of compression in the left jug. I worry about whether I got the rocker shafts right or wrong, I worry about whether the machine shop put o ring seals when reinstalling my valves.
I learned a ton in this thread that will serve me well upon tear down and reassembly. I will get thru it quickly, and most importantly, correctly.

Things I learned:
How to set timing with a time wheel printed from this forum (remember, I don't have any degree marker plate)
How the norton feels to kick start (nothing like my Triumph)
How the norton oil pump is gear driven (nothing like Triumph)
How to plane the oil pump and refresh it
How much oil is supposed to be in the sump, more importantly how much oil is not supposed to be in the sump (2 cups)
How Norton heads are overly oiled
Where to check the drain down from head for clogging
That there are seals on 2 of 4 valves (I don't remember any, but machine shop did it)
The rocker shafts only go on one way

I will look to all of these things and more. I am not afraid of going into the motor. I know the basics of Brit motors, you guys have taught me the nuances specific to Norton. I will go tend to them and report back.

If there is anything else anyone wants to suggest I look for while I have that motor open, a hint about this Norton goodie here, and tidbit about a Norton that insider there.... let me know. And if I have a question about anything that my POS norton book doesn't address, I will come one here and search former threads.

Its often a labor of love stealing from everything else in your life to have a Commando to call your own, ugh.

Only need valve stem seals on intakes and no sucktion into chamber ever seen on normal exhaust side.

Have the crank shaft balanced while its in hand, few hundred bux that can make you glad for couple decades. Balance the side to side parts fairly close too for sweeter nothingness isolastics. Check crank end run out/off center wobble. Get correct matched oil pump base gasket, oil nipple and TS cover gasket combo set. Extra's are handy.

Don't over tighten primary or drive chain, check for sure hot. Start thinking about tach drive oil seal solution now too, ugh.

You eventually will want to nail down swing arm spindle with the collars mod kit.

Since you've been in the motor recently, it will be lots easier. You can concentrate on the issues instead of the whole shebang. If you're not pressed it won't take that long either.

Re: hobot's thread on balance, my con rods and pistons were out by a measurable amount. I did grind off some of the steel con rod cap on the heavy side, but never did get real close since I was uncertain if I was doing it right, having no experience there. If I knew what I do now, I'd most likely go for the JS long rods and lightweight pistons. Plus a dynamic balance if it were available locally. My bike has never given me much in the way of problems though, just the oil leaks and I think I've just about got that taken care of. There is a buzz that doesn't go away until about 3.5K, the mirror is clear and it doesn't walk across the floor on the centre stand at idle or revving.

Dave
69S

Ditto to everything hobot writes ... I would also recommend SEVERAL viewings of the Norton rebuild video with Mick Hemmings as well.

Well, I think DogT is onto something here about yer breather too. Someone at some time installed a "breather fitting" in the top rear of your timing chest, then attached a hose to it ... and it looks like it's going on the ground; NOT good ! With this mod, you want that hose going to the vent chamber of your oil tank. And preferably, install a one way breather valve in the line too. ( I use the one from mikesxs.net and it made a HUGE difference for me. After my rebuild it leaked everywhere, but not after this mod) I've attached some pics of mine, so hopefully you can see what I'm trying to convey. As far as the "stock" breather hose coming off your camshaft ... stick a bolt in it like mine shows. When I rebuilt this motor, I did remove the spring and timing disc from the stock 750 breather, off the end of the camshaft. You also have to have your oil tank vent as well. I run a tube from the fitting where your oil tank cap is, routed to vent behind the rear wheel. This is also VERY important. The stock routing was into the air cleaner ... but I run a single Mikuni. We all feel for ya, owning a Commando sure tests one's manhood, patience, and tests yer mechanical skills fer sure. Hope this helps ...





You can just barely see my "mikexs" breather, just above the rear isolastic collar on the bottom picture. From there it makes a 90 degree turn, and the hose ( a smaller one now.) goes into the vent chamber of the oil tank. When I rebuilt my motor, I initially didn't have the breather valve ... and my motor leaked ... er ... everwhere. Then when I installed the breather, no more leaks.

Whoa, quick question for nortriubuell... that can be capped? Because that is where oil just squirts out on my bike. Massive amounts. But ok to cap if the other mod is done?

westernjesus said:

Whoa, quick question for nortriubuell... that can be capped? Because that is where oil just squirts out on my bike. Massive amounts. But ok to cap if the other mod is done?

Click to expand...

The side breather can be capped, BUT ONLY IF YOU HAVE ANOTHER BREATHER.

That's the only time you'll see me use all caps. :mrgreen:

If you cap that tube out of the LS of the crank, you will need some other engine breathing arrangement, usually done at the old magneto position, as nortriubuell, or better at the bottom of the rear of the engine. If you have tons of oil coming out of the old crank breather tube, you might want to check for the timed breather disk. Take off that 90 degree bend tube and look in there while turning over the engine, you should see a blanking disk behind the hourglass shaped cover on the end of the cam that rotates. If it's not there, block it off and figure on a new breather, but NOT no breather. I measured the oil coming out of that breather tube on mine and I get maybe an oz. of oil coming out of it on a recent start, but if it sits overnight and has wet sumped, it can pump out a pint or more, but that goes away as the oil is returned to the oil tank and the sump is emptied.

You might want to read some of the breather threads as confusing as they are.

Dave
69S

Ok, good. There was another breather installed where the old magneto used to be. That one has leaked little to none. Might change though if other is capped. the original breather is a constant leak, it never stops...

I've attached a couple more pics to show how my leaks were fixed. Two corrections to my earlier "input" though. My breather goes from the back of the timing side case ... to the mikesxs breather ... and then to the TOP tube; right where the oil tank cap is.
(My earlier post said it went to the vent chamber, wrong ! Sorry. )





And, my oil tank breather pipe goes from the vent chamber of the oil tank ... loops around and is tie-wrapped to the left side frame down tube ... then "breathes" on the top of my rear chain.



I would then close the hole with a bolt where the stock breather at the camshaft is (like mine) I can't take the credit for this modification either. I found out about it thru this forum and the INOA tech digest. Works a treat too !!!

Nortri-, beautiful views and neatly done effective vent hosing, but jeeze Louise don't you take her out for a spin, as so dang clean not even road dust behind stuff. Mine get so grimed dusted bunnies even when so oil tight the nuts rust.

Many claim its important to place check valve near engine but on Ms Peel rusty oil tight Combat, a Krane PCV placed up by oil tank functioned just fine. I figured that more volume in hose and case would tend to lower the pressure spikes and not impede the PCV operation.

About hardest leak to tame is the tach drive and I'm told that needs a machined in seal but open to other suggestions. I stuffed an oil pump nipple in Trixie but oil puddles then blows all over everything it spending much time over 70. ugh.

Well, I originally had a "motor mite" brake breather valve at the top. Then I read some folks on the forum were having problems with the motor mite valve, so I got paranoid and bought a heavy duty one from mikes xs (actually designed for this purpose.) I also read on the forum about placement; close or far ??? (from cases) Ended up putting mine in the middle, duh. However, me thinks I'll follow hobots advise and move it up by the oil tank. As far as my "actual" oil tank breather hose; think I'll move it back to exit behind the rear wheel too. (like on Triumph OIF pre T140E models) Can't recall why I shortened the hose; maybe so it could "breathe" a light oil mist on the chain ??? However, no oil mist seems to ever come from there to oil the chain ! Did I read it on some post of this forum, and then do it ???

I too had the "tach drive seal oil leak" problem. Then had the mod done by Phil Radford at Fair Spares ... no more leak.

Not meaning to "hijack' your thread westernjesus; just wanting to share info of breather fixes. Had Nortons since 1982; and I'm still a learnin' too ...

G'day Westernjesus,
Firstly.. Hang in there, I'm assuming that you don't swear (cuss) but sometimes it can help.
Way back you said that you had found a different coloured Gasket sealer to the one you had used, in various places.
Well sorry to say this but I think the whole engine has to come apart and all oil galleries checked and cleaned. Otherwise you will never be sure.
Please read.. " Compound Fracture Part 3 " It might make you feel better, AND, help you to realize that unless you have complete
confidence in who ever rebiulds your engine, wheather it be you or a friend or a shop charging $$$ then you will never be confident
with your 40 y.o. bike.
I now believe it is mandatory to do a COMPLETE engine rebiuld when starting out with a new second hand Classic English bike, unless you are
100% confident that all has been done. I will never pay $$$ for a bike that has supposedly been done again.
Gasket goo can find it's way in every where. Use it sparingly. As can large and small pieces of metal. See: "part 3" 5/16 unf Nut in oil gallery.
Short cuts by naive mechanics or just the inexperienced or Dodgy, can be very... costly, annoying and embarrasing .
Keep on going, when you do eventually ride it , all will be almost forgotten.
Also remember.. A Norton rebiuld is never complete.
You will go from this to this
AC.

Hello group... So I am down working on the bike this weekend. I started by draining the sump, then started her up, let her run for a bit (still smoking) then turned her off, drained and measured oil from the sump. A cup or less. So not wet sumping. Pulled rocker covers, looked around in there, clean as a whistle, everything looked good, no obvious excess oil. Disconnected the oil to the top end, started it, let it run for several minutes, still smoked like mad and misting oil out the tail pipe. No change. So, not much left too do, not much else that could cause this. Tore down the motor. nothing obvious was wrong from looking at it, but upon further inspection there are some parallel lines up and down the cylinder, not scarred, but visible wearing, and it probably has less than an hour on the motor. The parallel lines would be from the oil rings. Mic'd the bore, and it was .034 over. (let me say I was wrong when I said I took it .020 over, I guess I forgot that we took it .030 over) So the bore was off. Guess I did too much honing? :/ So in summary, even though I redid the motor, I must not have done it right. I am hoping it was indeed a piston/ring issue. sucking oil up past rings and also allowing compression past under fire (hence squirting oil out the breather). So the jug goes to the machine shop this week and taking it .040 over with new pistons and rings. Will report back in a couple weeks once reassembled again. I think this will fix it, and with hints learned on here, will make sure top end reassembly is absolutely correct. But sorry, I cant afford the work to the crank. I think that is fi.e and can be done some winter after tax returns

You might want to check out that fast break in thread when you get it done.

Dave
69S

WHOA WHOA WHOA Why are you reboring the cylinder? .004 is not too much piston skirt/cylinder clearance...or do I misunderstand what you are saying? Can you post a picture of your cylinder bores? Also measure your ring end gaps and piston skirt clearance and post too please. Something tells me you still haven't found the problem. It would be a shame at this point to keep throwing money at it and not solve the problem.

Mike

Gotta make it quick, but the maximum ring end gap according to my norton book is .12 but my ring gap was .16. According to my book it needed to be rebored. This seems to match up with what I suspected.