Amal carbs and spark plugs issues and concerns

Tornado said:
Broken collar? If your bike has the "Y" type headers with a connecting section then the collars are supposed to be split to allow assemble around the header pipe flanged ends...there would be no way to put an unsplit collet over the flanged ends.
Click to expand...
It was broken in two pieces, no longer just split.
 
arcpoint said:
It was broken in two pieces, no longer just split.
Click to expand...
Yes, it is supposed to be in two pieces....you place the two halves between the finned rose nuts and the pipe flanged ends, then the crush washer goes btwn flanged end and the head.

Have a close look at the correct parts diagram for your bike...can see them over on AndoverNorton website parts sections by model/year.
 
Tornado said:
Yes, it is supposed to be in two pieces....you place the two halves between the finned rose nuts and the pipe flanged ends, then the crush washer goes btwn flanged end and the head.

Have a close look at the correct parts diagram for your bike...can see them over on AndoverNorton website parts sections by model/year.
Click to expand...
The left one is one piece with a single slit/gap. The ones I just ordered look like the one I have that's not broken. Do you have to break them to get them on? I figured pull apart with some flex return. Now I'm really confused.
 
arcpoint said:
The left one is one piece with a single slit/gap. The ones I just ordered look like the one I have that's not broken. Do you have to break them to get them on? I figured pull apart with some flex return. Now I'm really confused.
Click to expand...
No Andover Norton is like mine, one piece with a slit in one location. Part #
06.5260
EX. PIPE RETAINING COLLET
 
arcpoint said:
It was broken in two pieces, no longer just split.
Click to expand...
Found this older thread where the MK3 setup is described more:

www.accessnorton.com

1975 Mk3 exhaust downpipe fitting

Hi again everyone my exhaust front pipes are not the standard balanced pipes but are I believe earlier commando pipes unbalanced and fitted to pea shooters I had to remove my right side down pipe and when doing so 2 collets and a domed washer fell out and I did not see how or in which order or...
www.accessnorton.com www.accessnorton.com
There are no crush washers for MK3...just the slipt collet and a semipherical seating ring....no gaskets or crush washers used. The linked threads also mentions the collets are usually found to be fully split in to two halves....which is also how I found them on my '74 MK2 bike with the Y-type headers...though different than the MK3, using a crush washer and no semipherical seats. Perhaps AN sells them as single collet with a split and these need to be broken in two to fit over the pipe? Should not make any difference as they are only to engage with roses and press against the seating rings...should not matter if two halves or not.
 
johnm said:
I mentioned leaking header pipes as a very common source for backfiring in the third post on the thread. In fact in 50 years plus of playing with these bikes it's the issue 90 % of the time.

Your bike us a Mk 111. Which, should if it is original, have a different slightly different mounting system in the head. The same system is found on latter MK11 and Mk11 A models.

Originally it would have had a balance pipe between the headers. Many people take them off and install pipes without the balance tube but if you still have the balance pipe the joints are a very common place for leaks.

With a Mk 111 type fitting there are collets that secure the pipe into the head because the balance pipe joint does not allow the clamping ring to slide on from the other end of the header pipe.

andover-norton.co.uk

Andover Norton - EXHAUST PIPE RETAINING COLLET - 06.5260

EXHAUST PIPE RETAINING COLLET
andover-norton.co.uk

If you do have the original collet system you should clean everything carefully and without the pipe installed screw in the clamping ring with the collets and measure where it ends up when fully screwed in. It should screw in by hand. No force required. Often you find the gap is wider than can be taken up by the header pipe flange and a single ring gasket. If it is you can try two gaskets or even longer collets if you can find them.

You will understand the explanation better if you just trial assemble the pieces.

When you get the space out right assemble with the pipes and use high temperature RTV to seal and hold the clamping ring in place. After your first few rides when the bike is still hot retighten the clamping ring. You may need to do this several times. There are proper spanners available to tighten them without butchering the clamp.

Last issue is that the threads into the head can be ruined by careless owners. If the threads are ruined they can be repaired. Your in the US so Ill leave to the local guys to suggest a suitable repair place.
Click to expand...
Thanks, John. Turns out I had a broken collet and will follow your instructions to a T.
 
Tornado said:
Found this older thread where the MK3 setup is described more:

www.accessnorton.com

1975 Mk3 exhaust downpipe fitting

Hi again everyone my exhaust front pipes are not the standard balanced pipes but are I believe earlier commando pipes unbalanced and fitted to pea shooters I had to remove my right side down pipe and when doing so 2 collets and a domed washer fell out and I did not see how or in which order or...
www.accessnorton.com www.accessnorton.com
There are no crush washers for MK3...just the slipt collet and a semipherical seating ring....no gaskets or crush washers used. The linked threads also mentions the collets are usually found to be fully split in to two halves....which is also how I found them on my '74 MK2 bike with the Y-type headers...though different than the MK3, using a crush washer and no semipherical seats. Perhaps AN sells them as single collet with a split and these need to be broken in two to fit over the pipe? Should not make any difference as they are only to engage with roses and press against the seating rings...should not matter if two halves or not.
Click to expand...
I get it now. This helps. I have the new seating washers and will go ahead and wait for the collets to arrive. I should've able to get a good seal, and with the cross pipe as well. Thanks! Will let you know how it goes.
 
arcpoint said:
Thanks, John. Turns out I had a broken collet and will follow your instructions to a T.
Click to expand...
Hi.

I read the discussion about one piece and two piece collets. To be honest it probably hardly matters so long as you can get them to stay in place while you assemble the pieces. In my experience the critical thing is to ensure the stack of pieces are spaced out correctly. So that the clamping ring can indeed clamp tge pipe into the head without any movement in and out. I have never worried about adding an extra crush washer if needed. Just make sure the pipe is firmly clamped into the head. And use high temp rtv to stop it unwinding. Give it a few check tightening when warmed up and after a few rides. Its all dead easy and obvious once you look at it. 👍
 
arcpoint said:
Can someone tell me if my plugs and valves are getting black am I running rich or lean? Pretty sure I need to try hotter plugs, but what about the timing?
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Rich mixture makes plugs sooty. At what throttle opening are clean plugs becoming sooty in your engine?

Too-hot plugs cause pre-ignition and holed pistons.

What about the timing?
 
Triton Thrasher said:
Rich mixture makes plugs sooty. At what throttle opening are clean plugs becoming sooty in your engine?

Too-hot plugs cause pre-ignition and holed pistons.

What about the timing?
Click to expand...
There are two ways of getting jetting and timing right, presuming you are not changing anything else. You can set the timing to a fixed value and jet to suit it. Or it you have a dyno you can get the jetting correct using an oxygen probe and advance the timing until you get maximum torque. Either way you start with jets which flow to much and progress to smaller ones. You should use the next hottest heat range plugs for tuning. As you lean-off the jetting, the carbon will burn off further down the porcelain inside the plug. When you use recommended heat range plug, a block band about 2mm wide should remain on the porcelain right down inside the plug where it neets the metal. Your plugs should not be black, nor should they be totally white. The black band must be there. If the motor misses when you ride the bike, stop and raise the needles one notch - do not persevere.
 
arcpoint said:
Wow, first off, a huge thank you to Ashley, Greg, John, and Illf8ed for the insightful responses! The ignition is a Boyer electronic with Boyer voltage regulator. In 2021 the carbs were given new floats, jets, and needles. The resistor caps and spark plug wires seem typical new old school but wouldn't know a resistor cap or wire if it smacked me in the face. (You can tell I've been away from bikes for a while, a long while). The battery is strong. I will check for leaks at the manifolds and headers and everywhere else plus make sure of no over tightening on the carbs, etc. Thanks hugely for the links and the Amal tuning guide. I will study that pronto. I want to ditch these plugs for more standard fare but am nervous about getting a non resistor plug and causing problems. The bike also got new Barnett clutch discs and steels in 21. But have had a few times when putting into 1st it wouldn't engage, yet wasn't in neutral. Had to kick it up into 2nd and back to 1st to engage. Any thoughts on thos?
Click to expand...
 
There are predictable issues that arise with a dry clutch being housed in an oiled chain case. Clean clutch plates give a nice shift…oil can tend to migrate progressively into the inner plates. Variables…use the minimum amount of oil to get lube on the chain without getting oil into the clutch. Leaning the machine too far to the left ( side stand on ground sloping away) can let oil into the clutch. Some people use ATF to keep the primary lubed while degrading clutch function less than heavier lubrication.
 
Parsifal said:
Some people use ATF to keep the primary lubed
Click to expand...
Pefectly fine in a pre-Mk3 primary but not generally recomended for a Mk3 as it's not compatible with the automatic primary chain tensioner.
Parsifal said:
Variables…use the minimum amount of oil to get lube on the chain without getting oil into the clutch.
Click to expand...
It isn't a good idea to run the Mk3 chaincase with less than the recommended amount of oil because it also has to fill the primary chain tensioner.
 
Oil will (must) always get into the clutch, or the clutch bearing would run dry.
You can't have it both ways.
 
Last edited:
The clutch bearing is only used when the clutch is held in when the motor is running and a gear is engaged. Normal practice with a dry clutch, is to grease the bearing. With a road bike, disengage the gears when stopped at traffic lights.
 
With a road bike, when I stopped at traffic lights I always held the clutch in with the motor running, in case I needed to move in a hurry. It might be more sensible to shift into neutral, however I would not do that.
 
trappnman said:
IMNSHO, holding the clutch in ar a stop light, with it in gear, is a dangerous "rookie" move, don't care what your miles or experience is.
Click to expand...
Alternatives:
1) Sitting in neutral, car coming fast from behind. Pull clutch, put in gear, hit gas and release clutch, live?
2) Sitting in 1st, clutch in, car coming fast from behind. Hit gas and release clutch, live?

IMHO, the chance of continued life without injury is better with #2.

Please explain the danger you see sitting in gear with the clutch in.
 

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