decompression

Anonymous

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Does anyone know off any decompression device that could be installed on my 850 norton, I have a hard time kicking the thing over.I,m working on a fix for the electric start.
 
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Maybe you need to do some "leg strengthening" exercises ?
Are you male or female ?

Debby may pounce on me for asking that one :D
 
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I think there are two easier options

1 - I may be corrected.. but I believe the Mk III Commando kick start lever is slightly longer than the earlier models.
This would give a slight mechanical crank advantage/ improvement .

2- Failing that I find that (pulling the clutch in ) lowering the kick lever to horizontal/ right angle/ half mast position is extremely effective and easier in kicking over the Commando engine.
And I find that the engine, in good tune , will always fire from this position.
 
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nortonfan said:
Maybe you need to do some "leg strengthening" exercises ?
Are you male or female ?

Debby may pounce on me for asking that one :D

I kickstart mine with no problems. No choice, I don't have no stinkin estart. I cold-start on the centerstand, less chance of slipping off and injuring myself. I do warm starts off the stand, with both wheels on the ground. But my bike is a first kick starter now so it's not that big a deal :D

Of course I'm tall and have a background in athletics (mountain bike racing). That probably helps a bit. It's really technique more than brute strength or body weight though...

Debby
 

MichaelB

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There is no compression release available for the Norton Heavy Twins.
Anything can be fabbed, I doubt anyone here has seen one.
Kick starting a Norton does border on the side of black magic, one of the things that make them so darn cooool.
However they do need to be in correct working condition and well tuned.

I agree with Dyno Dave about the internal movement of the engine. I've never tried to hand start one, but if you can't rotate the engine by hand with the plugs out, somethings wrong. 145 psi correct. My Mark III checks in at 142 / 145. This is of course for a stock engine.

After you know the internals are OK, Here is a check list.

1. Make sure kick start arm is tight on shaft. VERY tight. It can't be too tight. If it still has slop after tightening, replace it. It will hurt you.
2. Make sure it hasn't wet sumped. Does this need an explanation?
3. Set bike securly on center stand.
4. Tickle or choke as necessary.
5. Ratchet pistons to TDC, Give healthy kick, NO THROTTLE, til it fires.
If it doesn't start within three kicks, somethings wrong.

Good Luck
 

Ron L

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Debby,

If you are cold starting on the centerstand, I strongly suggest you have the late style (850) re-inforced stand. The 750 style stand WILL break from the twisting stresses of kick starting it on the stand.
 

Anonymous

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compression plate

There are two compression plates avable for nortons from Noril. I fitted the .75mm and the bike became much mor managable lower idle and the power band seemed to drop. My problem with pre ignition disappeared.
 

Anonymous

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Ron L said:
Debby,
The 750 style stand WILL break from the twisting stresses of kick starting it on the stand.

funny you should say that...I broke three of them years ago, solved it by taking the last one that broke to a welder, he shoved steel rod down the broken tubes, put the pieces back together and welded it together. It weights more than the standard stand, but it hasn't broken in 30 years now...peace!
 

Anonymous

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Kick it, kick it good

Fit the later model kicker and make sure the pinch bolt is nice and snug and use loctite and check it often. It will work loose, especially if the kicker is slightly fouling the pipe on the downstroke, you might not even notice it until a faint scratch appears on the pipe. Re-hang the pipe and that takes care of that.

Anyone of any size can kick a Norton. You must have it on the centerstand. Make sure you kick it through once to free the clutch plates, unless you have a Barnett "snatchy" clutch fitted. Next, get up on that kicker with your right leg and keep it slightly bent in case your timing is off or the timing chain is loose (it will bite back). Now comes the fine art part. Using your body weight as leverage, push down like you are climbing a big step. The combo of body weight and the "push" will allow you to kick it through. And like a good Norton with freshly tickled Amals and a choke set just right, it will fire up right away.
 

ntst8

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Assuming you still have amals they would have originally had chokes.

Mine had been removed before i bought and i have not missed them. Managed to kick start the morning after the Norton had slept outside with 6" of snow on the ground at a midwinter rally - just can't let go of the throttle 'til things warm up.
 
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John
After owning some seven brit bikes. I reckon the chokes are purely for dress.

But then this is Australia and we don't have a lot of snow and bitter cold stuff..

Although I did own my second A65L in Canberra which can be mighty ~ bloody chilly at times..
 
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Re: compression plate

sway said:
There are two compression plates avable for nortons from Noril. I fitted the .75mm and the bike became much mor managable lower idle and the power band seemed to drop. My problem with pre ignition disappeared.

What does the compression late do? Does it make it easier to kick?
 
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A compression plate fits underneath the barrel and moves it up with the head so reducing the compression, unlike a decompressor it is a permanent full time reduction so you lose power but it is easier to start.

If you have not had the bike long and are new to kicking then I would not go the compression plate yet, get the bike in proper tune eg valve clearances, carbs cleaned and jetted and practise the technique, also flood the carbs a lot as mine needs a good flood from cold.
 
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kommando said:
A compression plate fits underneath the barrel and moves it up with the head so reducing the compression, unlike a decompressor it is a permanent full time reduction so you lose power but it is easier to start.

If you have not had the bike long and are new to kicking then I would not go the compression plate yet, get the bike in proper tune eg valve clearances, carbs cleaned and jetted and practise the technique, also flood the carbs a lot as mine needs a good flood from cold.

Thanks for the quick reply. I'm wondering how much compression is lost with such a small spacer (.75mm) doesn't seem like much. Never had trouble starting the 650 twins. Wet-sumping is probably making it harder as well.
 
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