Norton Commando 1969 timing issues

concours

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"At least the top engine was done it has clean pistons. I was told it was a Norton guy that rebuild the engine but don't know any details. I rebuilt the wiring harness and everything on that end seems to be doing it's intended job."

You have two very big question marks here. The first needing more investigation, as previously mentioned, timing cover off.
 

DogT

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camlinks.jpg

Notice the dots and the links between the dots. There are 6 links counting each link on a dot. Or 4 links if you don't count the dots. Notice the dots on the lower gears too.
 

Carl H

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View attachment 78762
Notice the dots and the links between the dots. There are 6 links counting each link on a dot. Or 4 links if you don't count the dots. Notice the dots on the lower gears too.
Another way to do it is 10 pins between the dots. Lucky the bike has a Boyer in it , resetting the timing on a dual point OEM ignition is not a job for the faint hearted. It just dawned on me, that before the timing cover point ignition, It was easy, breezy to check a cam chain for slack, Just remove the timing cover screws and pull the cover, re gasket it and put the screws in. Luckily the MK3 inspection hole solved some of the headaches and heart breaks. That is one job I hated as the better part of 1/2 a day could go by doing it. And some times the cam chain slack was Ok as is.
 

DogT

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I can remember pulling off that AAU several times and wondering if I would ever get it back on correctly. I think I finally took a picture of it with the rotor mark on the timing hole marker.
 
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One thing that could be a fly in the ointment, (Some thing that could be a problem:) The alternator rotor outer is broken away from the center, so the timing marks are not in the proper position. This is more common on Triumphs, not so much on Nortons.

I dug out my Combat work records as I was setting the cam timing with a degree wheel and also checked the 28 and 30 degree BTDC of the pistons.. So,, 28 degrees BTDC on the degree wheel Or the Norton timing plate= piston is .270" BTDC,

at 30 degrees BTDC piston is .305" BTDC on the compression stroke .

Simply put: get the piston at top dead center on the compression stroke , then back the piston down ( turn the engine backwards) to get the piston lower by .305" and the alternator rotor mark should be at 30 degrees on the clutch cover timing tag. Or very close to it.

IF you use those numbers, that will help confirm if the rotor marks when lined up with the timing degree plate line up properly, Give or take a little.

In the old days with Triumphs , I had a small screw driver with marks on it for TDC and 38 degrees before TDC. It was close enough for me and saved time.
That seems exactly like what I did. I got the connectors to test the boyer EI on the T140 but I still haven't got the time to do it this week due to work. I will update you guys asap. Thank you all
 
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I never rely on timing marks - always use a degree disc and find TDC with a broken spark plug with soap bubble. A very small difference in crankshaft rotation makes a very big difference in soap bubble position in the hole in the plug where the electrode used to be.
The timing marks in engines are put in by special men who have dementia.
 
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One thing that could be a fly in the ointment, (Some thing that could be a problem:) The alternator rotor outer is broken away from the center, so the timing marks are not in the proper position. This is more common on Triumphs, not so much on Nortons.

I dug out my Combat work records as I was setting the cam timing with a degree wheel and also checked the 28 and 30 degree BTDC of the pistons.. So,, 28 degrees BTDC on the degree wheel Or the Norton timing plate= piston is .270" BTDC,

at 30 degrees BTDC piston is .305" BTDC on the compression stroke .

Simply put: get the piston at top dead center on the compression stroke , then back the piston down ( turn the engine backwards) to get the piston lower by .305" and the alternator rotor mark should be at 30 degrees on the clutch cover timing tag. Or very close to it.

IF you use those numbers, that will help confirm if the rotor marks when lined up with the timing degree plate line up properly, Give or take a little.

In the old days with Triumphs , I had a small screw driver with marks on it for TDC and 38 degrees before TDC. It was close enough for me and saved time.
What are 'work records' ? Do real people actually write things down ? I never do that, it makes things too easy. Some things I never forget. My main problem if finding tools which fit the variety of screws and nuts on my bike. I have got BSF, Brass thread, UNF, Whitworth, Cycle thread and Metric. After I have worked on my bike for a few hours, the correct tools simply appear in my hands.
 
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If I ever move the ignition timing, I always check that my jetting is right. The slightest extra bit of advance beyond what you had preciously can have the same effect as leaning off the fuel. Even strobing the ignition is not good enough, if you tune for max. performance. It is a very fine balance and one thing leads to another.
I think most road bikes are jetted slightly rich - performance is slightly less, but OK. So the ignition timing is not so critical.
 

Carl H

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What are 'work records' ? Do real people actually write things down ? I never do that, it makes things too easy. Some things I never forget. My main problem if finding tools which fit the variety of screws and nuts on my bike. I have got BSF, Brass thread, UNF, Whitworth, Cycle thread and Metric. After I have worked on my bike for a few hours, the correct tools simply appear in my hands.
Well some of the old records helped me out on the Combat as I started to do the job 30 years ago, so when I found the old shop notes I saw I had gone thru the gear box, so that made me feel real good as I dumped a tons of parts in it. And as far tools that go astray , I figure I have a ghost that hides them on me and suddenly they appear where I had looked 10 times the day before. But now that I am trying to record Compression ratio, cam timing and jetting on several bikes at a time. The notes help me know what I did the day before on which bike I dun it on. I should write notes on where I put the tools too, or put tracking devices on them to save me from hunting for them. But the ghost would probably hide my notes and then I would be looking for them too.
 
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Hi everyone
Sorry to keep you guys waiting but only yesterday night I was able to work on the bike again.
So I exchanged the norton boyer EI and connected in the T140 without being able to start it.
I noticed that the MK3 EI that I removed from the norton developed a bend from being strapped to tight to the frame.
Decided to try out the MK4 from the t140 on the norton and what a difference. In one kick I could see 3-4 sparks has opposed to just one per kick like before. I think we can assume the other Boyer was knackered.
After that I placed a tea spoon of gas in each barrel and tried to start the bike. Got one pop from the pipes each kick but not like backfire instead it was almost like it was starting to start but never did. I am still gonna give it another shot now. If I am not able what would be your next test/recommendation to follow? To check the camshaft chain?

Many thanks!
Cheers
Miguel
 
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Miguel
Excellent...
If you can pick out the correct procedure already posted for moving to verify mechanical integrity and timing (compression). no need to repeat it again....unless you want a simple procedure or a complex one!
Fuel/carbs can be last as " a teaspon of fuel in the spark plug hole" will get you at lease a start-up zoom!
:)
 
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I will do so then. Just came back from the bike and managed to get 3 pops from the pipes so I think I might be close. I will remove the cam cover and have a look. Also I ordered a compression test kit and a strobe gun but it won't get here any time soon. I am bundling up everything that is coming from the UK. I need to add the boyer electronic ignition as well.
Also worth mentioning, the breather hole facing the air filter is welded shut plus there is a hole on the oil reservoir cover that I don't believe it's original that blows air from the engine each stroke. Is that acceptable or am I in for a treat?:rolleyes:
 

Carl H

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Most all Commandos wet sump. The oil in the oil tank leaks in to the engine base, so most all the oil in the oil tank is gone. So I would drain the engine base. and see how much oil drains out . And then add oil to the oil tank if it is low. The oil tank top vent is needed. What size hole is in the oil tank cap? If you bike has wet sumped. getting the oil out of the engine base may help you start it as it will kick over easier and faster. Why don't you just try to push start the bike Or get some one that is better able to kick the bike over faster. If you don't have a good firm kick to spin the engine they don't start, ( at least in my cases)
 
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So the lower gears from the cams aligned and and the both cams dot aligned up like in the image. It seems to be like described 4 links between dots, 6 links on the dots and 10 pins between dots. Just slacked the chain a bit because it seemed to tight. Adjusted to 3/16 inch approx 4.7mm in the middle of the chain.
The hole in the oil cap is 2mm diameter.
So next should I try and drain the sump and try again?
 

DogT

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That hole that is in the front of the oil tank, inside the air filter, is there for a reason. It allows the oil tank to breath to the atmosphere (actually into the air filter, same thing). If it's blocked off the oil tank will likely build up pressure, that's probably why there's an extra hole in the tank. That hole that is welded over is a tube that goes back into the oil tank, bends straight up and ends in that 'top hat' gizmo on the top of the tank. It supposedly allows air pressure to vent into the air filter, supposedly. Trouble is when the engine wet sumps or someone fills the tank too much, and even just oil vapor ends up dripping out of that hole in the front of the tank into the air filter, oiling up the filter and then it drips down onto the top of the gearbox, further dripping down to the bottom of the engine and then all over the rear wheel.

Sorry for the long story, some have luck with that breather, I didn't so I attached a catch bottle to that hole in the front of the oil tank with a threaded nipple, it catches the vapor and oil that wants to come out there. The 69/70 engine has a 'timed breather' on the left side of the engine, there's a hose that connects it onto a spigot somewhere on the top of the oil tank, and supposedly this allows extra sumped oil from the engine to return to the oil tank. Trouble is that timed breather is minimally useful at best. There are better options out there, but the first thing is getting the bike started then you can work on the other stuff.

Yes I would drain the sump, make sure there's enough oil in the tank, don't get it much past the bottom mark or you will have oil squirting all over the place. If the bike starts, always take off the oil tank cap, and right in there should be a pipe with a hole in it. Make sure oil is returning out of this hole after a half minute or so, it may start right away, but if there's no oil coming from that hole into the tank after a few minutes, your top end is not getting oil. Shut if off and go to plan B.

I still think 'hill starting' it would be a good idea, but do check that return line inside the oil tank if it does start. I'll bet you find a bunch of oil coming out of that hole in the tank unless there's a tube that lets it go somewhere else, like the ground.
 
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I will do so and report back. I have no proper hills around here to try and start it but I will do my best!
 

Carl H

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I will do so and report back. I have no proper hills around here to try and start it but I will do my best!
Have a few friends push you, use 2nd gear or a higher one, Check the oil return to the tank as soon as possible to be sure oil is flowing back. It would be a good idea to squirt some oil into the head by removing the valve covers to be sure the top end is lubed. Did a lot of oil come out of the base when you drained it???

Make sure the clutch will disengage by pulling in on the handlebar lever and then operating the kick start lever to be sure the clutch is freed up , before starting as you need to be able to stop the bike, Be ready to use the key or kill switch in case something goes wrong
 

Carl H

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So the lower gears from the cams aligned and and the both cams dot aligned up like in the image. It seems to be like described 4 links between dots, 6 links on the dots and 10 pins between dots. Just slacked the chain a bit because it seemed to tight. Adjusted to 3/16 inch approx 4.7mm in the middle of the chain.
The hole in the oil cap is 2mm diameter.
So next should I try and drain the sump and try again?
Temporarily you can vent the oil tank by leaving the oil cap off , that way you can check the oil return quicker.
 

DogT

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No kill switch on a 70 unless it's been added. Use the ignition key, it's only on or off. And yes clear the clutch. The return oil may be frothy in the beginning. Not to worry, just make sure it comes out.
 

Carl H

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No kill switch on a 70 unless it's been added. Use the ignition key, it's only on or off. And yes clear the clutch. The return oil may be frothy in the beginning. Not to worry, just make sure it comes out.
Once years ago I friend asked me to try a ride on an new RD350 Yamaha, So Off I go and after a short ride I'm taking off and rev up the bike and the carbs slides stick and the engine is screaming, so I just let the clutch out and it stalls. So I ride back slowly and tell the kid, and he says "Oh yeah the carbs stick", so I tell him "If that was my Commando, I would have bee in one hell of a wild ride". Luckily the 2 stroke was gutless and had no torque or something bad could have happened. I like kill switches and in racing they are required.
 
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