Timing install issues 69 commando

Pdr206

Pdr206

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Jul 23, 2020
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Hello. Finally got my hands on timing parts. Installed following manual and whites book. seemed fine. Installed oil worm gear. Tightened worm to 20 ft lbs. tried spinning a few revolutions and chain would lock up/get real tight on top, another few degrees rotation it would slack. Then I noticed there was no way to attach the nut to camshaft. What the heck is going on?!

Dots on intermediate and cam gear are straight up and ten rollers apart. What position or ‘time’ does the DOT on gear behind the worm gear need to be? What position or ‘time’ does the cam Pin need to be at? Just wondering if I’m missing something here.

Drivetrain rebuilt by a now sold shop. No idea what cam is in it. Gears I’m using were advertised as out of a 1968 Norton.
 
Looking at Andovers site, its showing a intermediate gear bush and a thrust washer, which i do not have. I'm supposing I need the thrust washer as this may be putting the gears out of alignment. Thinking the cam drive sprocket is INCORRECT.
 
Put the crank pinion at TDC so the the timing mark is straight up. Line up the timing gear/sprocket so that one dot lines up with the dot on the crank pinion. The other dot on the timing/sprocket will be rapt roughly 11 o’clock. Then the chain is as you mention, 10 links between dots on the timing sprocket and cam sprocket. If you did not correctly line up the crank pinion you might be having valves collide with pistons.
 
By the way the camshaft for Commando S is different that the fastback for 1969.
 
Andover slightly decoded my motorcycle as a 1969 'R' - it was a basket case when I got it 3/4 years ago. Had MI MII and MIII parts with it. I basically got 'got' with the purchase and the engine rebuild.

Thank you for the information sir. I will try your instructions tonight.
 
Pdr206 said:
Andover slightly decoded my motorcycle as a 1969 'R' - it was a basket case when I got it 3/4 years ago.
Click to expand...

An 'R' should be a 20M3 twin timing chain model with the chain-driven points housing behind the cylinders.

As ILLF8ED says, the camshaft looks like a single chain 20M3S (camshaft points) item. The camshaft sprocket, therefore, is probably correct for the 20M3 engine but not for the (20M3S) camshaft.

The intermediate gear spindle also seems to be the later single chain type as it looks too short.
The twin chain intermediate gear should have the thrust washer.
 
Timing install issues 69 commando
 
Thank you L.A.B. This Norton has been such a headache.

What can I do to get the right set of FrankenNorton parts to run this thing?I have a good amount of money invested in parts that have turned out to be unuseable… like these timing parts. Should I do an engine tear down and just put the right cam and spindle in there?
 
Pdr206 said:
Thank you L.A.B. This Norton has been such a headache.

What can I do to get the right set of FrankenNorton parts to run this thing?I have a good amount of money invested in parts that have turned out to be unuseable… like these timing parts. Should I do an engine tear down and just put the right cam and spindle in there?
Click to expand...

Yes, the easiest thing to do would be to change the camshaft, intermediate spindle, etc, for the correct parts,
andover-norton.co.uk

Andover Norton Parts Drawings - Genuine Andover Norton Factory Parts - Commando Parts

Andover Norton Parts are the only Norton spare parts in the market manufactured to original drawings, within the factory-approved tolerances, from the correct materials, and with the correct finish.
andover-norton.co.uk
 
Okay. I should also be able to tell from the engine casting number, correct?
 
That mix of parts is not going to work. You have no way to install camshaft nut. You know how to reach me.
George
 
Pdr206 said:
Okay. I should also be able to tell from the engine casting number, correct?
Click to expand...

The engine number should be prefixed 20M3 /xxxxxx. Edit: Possibly also a '/P' suffix?

The 'R' type that it has been identified as, had the twin-chain 20M3 engine and continued into '69 with the points housing behind the cylinders, the same as the early Fastback.

The S type, however, had the 20M3S engine from approximately March '69. All models later had the camshaft points engine with the 20M3S prefix (although the prefix was eventually dropped at the beginning of the 200000 series).
 
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Also, the oil hole in the intermediate gear spindle should face down, not up as it is in your picture.
It should be tight in the case so use heat when replacing, or if loose, use Loctite (620? 638? 648?).
andover-norton.co.uk

Motorcycle parts and spares for Norton motorbikes - Genuine Andover Norton Spare Parts - Andover Norton Motorcycles Parts - Original Andover Norton Parts

Motorcycle parts and spares for Andover Norton motorbikes: Andover Norton manufactures and supplies all Genuine Factory Spare Parts for Norton motorcycles built before 2002.
andover-norton.co.uk
 
LAB I insist on getting you out to NJ. This project would have been done in half the time for half the cost! :) thanks for the information sir, you’ll be seeing me on this forum more within two weeks.

Looking for a best price camshaft at the moment.
 
PDR206 -- OK, let's go to basics here. First, check the serial number on the engine crankcases that you're using. There should be a prefix that's either "20M3" or "20M3S". Which is it? Also, to be sure that no numbers have been changed, look at the front corner of the cases right behind the timing cast. Is there a round hole (about 3/4") with two threaded screw holes, one on either side. If the cases have the "20M3" prefix on the serial number, they should not have the round hole. (The round hole is for the tacho drive.)
Once you've settled this, you'll be in a position to completely validate the correct parts that you need.
This detail shows a defining aspect of the 20M3S cases (used on some 1969 engines and all 1971-71 engines).
1667759885923.png


Here is the camshaft that matches these cases:
1667760037622.png

The red arrow points to the tacho drive gear -- it's the important part of what makes a 20M3S cam different from others.

I hope this helps. BH
 
Blewdy Yaink said:
PDR206 -- OK, let's go to basics here. First, check the serial number on the engine crankcases that you're using. There should be a prefix that's either "20M3" or "20M3S". Which is it? Also, to be sure that no numbers have been changed, look at the front corner of the cases right behind the timing cast. Is there a round hole (about 3/4") with two threaded screw holes, one on either side. If the cases have the "20M3" prefix on the serial number, they should not have the round hole. (The round hole is for the tacho drive.)
Once you've settled this, you'll be in a position to completely validate the correct parts that you need.
This detail shows a defining aspect of the 20M3S cases (used on some 1969 engines and all 1971-71 engines).
View attachment 101231

Here is the camshaft that matches these cases:
View attachment 101232
The red arrow points to the tacho drive gear -- it's the important part of what makes a 20M3S cam different from others.

I hope this helps. BH
Click to expand...

Ok, but had been identified as a 20M3 twin-chain engine (and pictures show) originally from an R type fitted with the wrong 20M3S camshaft in August.
 
L.A.B. said:
Ok, but had been identified as a 20M3 twin-chain engine (and pictures show) fitted with the wrong 20M3S camshaft in August.
Click to expand...
I don't know how I didn't pick that up (I went back and looked again) but that's an important detail to know. Sorry that my comment was redundant.
 
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