MK III Clarification + convert to kick start

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RennieK

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Hi all, I'm looking for clarification on the MK III types regarding e-start/k-start options. As I see it there are 4 possible variations between the roadster and interstate models.

#1 - E-start lt. shift
#2 - E-start rt. shift Never Existed
#3 - K-start lt. shift Never Existed
#2 - K-start rt. shift Never Existed

The reason I'm asking is I have a 1975 E-start rt. shift matching # bike that I'm taking the e-start out of. I'm thinking ideally it would be nice to change the chain cases to avoid having the "bump" sticking up from centre. Also and mainly, the standard engine sprocket fits the crank with the right spacing so is there a spacer that goes between the alt rotor and the sprocket to compensate for all the e-start bits and does anyone know the length of it?

Is this how the non e-start was configured with just a 4 part kit, the old style eng sprocket, spacer and 2 chain case halves?
 
A right hand shift e-start? a tool room special?

I think you will be opening a very expensive can of worms. The Mk3 crank is longer, I doubt that it will fit inside a pre Mk3 chaincase. the drive side engine case on your Mk3 has 4 threaded holes that are used to attach the Mk3 inner chaincase, pre mk3s have three holes. Your transmission cradle is not set-up to allow the transmission any forward or rearward movement, as do the pre Mk3s...I could go on.

If you really want a pre Mk3 primary chaincase appearance I suggest that you remove the part of the casting that you object to, have someone weld up the hole and the find someone that is willing to sand/machine/polish the result. I have a spare Mk3 outer cover that I'd sell cheap that you could experiment with if you decide to go that way.

Good luck on your journey.

RS
 
RennieK said:
The reason I'm asking is I have a 1975 E-start rt. shift matching # bike that I'm taking the e-start out of. I'm thinking ideally it would be nice to change the chain cases to avoid having the "bump" sticking up from centre.
Click to expand...

(RoadScholar just beat me to it)
Unfortunately it would not be a simple exchange of primary parts.

If you were to attempt to replace the MkIII chaincase with the pre-MkIII type, it would mean the automatic primary chain tensioner would also have to be removed, and there are no adjustment slots in the MkIII cradle to manually adjust the primary chain (or belt) so the cradle would require some minor modification.

I believe that to bolt up a pre-MkIII primary case would involve machining, (drilling and thread tapping) of the D/S crankcase (or D/S case and/or inner primary case?), as the MkIII inner primary to D/S engine case fixing arrangement is different to pre-MkIII (MkIII has 4 long studs, not 3 bolts).

RennieK said:
Also and mainly, the standard engine sprocket fits the crank with the right spacing so is there a spacer that goes between the alt rotor and the sprocket to compensate for all the e-start bits and does anyone know the length of it?
Click to expand...

The electric start crank drive sprocket inner race can serve as the spacer, however, the MkIII D/S shaft is longer so I doubt it will fit inside a pre-MkIII primary case unless the shaft was shortened.
 
OK, thanks for clarifying, I'm not very familiar with MK III's. I actually thought I'd seen a 4 bolt MK III chaincase set on ebay without the bump so was assuming Norton at sometime issued a non electric start style chain case. It must have been custom. I'll use the stock chain case with the hump as I haven't written off the e-start yet (or my knees). I'll just seal it up. I'll make a spacer to fill in the slack between the rotor and sprocket as I want to keep all the e-start "extra bits" together including the sprocket if ever I decide to go back to e-start.
 
I've really got a leg up on the competition now.

All of the starter components made up 6.1 KG of extra weight.

MK III Clarification + convert to kick start


The lighter sprocket, spacer and blanking plate weighed in at .75 KG so I'm shaving 5.35 KG of weight off the bike. I can't think of an easier way to lose 5.35 KG, think I'll go have another piece of pie. :twisted:

MK III Clarification + convert to kick start
 
Did you leave the hump in the chain case GP? Did you use the original drive sprocket and sprag bearing race as a spacer?

Nice shot of your bike!
 
Mine was already rt side shift. There is no sign of a linkage through the inner GB cover so I'm assuming this was factory as it's a matching # trans. I don't see any sign of a neutral switch around the frontward bottom face that I thought all 75's would have (maybe I'm looking in the wrong place). There is a shaft with circlip poking through the frontward face about mid height, next to the inner cover that I don't remember on the older trannies.

I have downloaded a MK III manual but I thought it was inconclusive mainly because I couldn't find anything of MK III K-start models :oops: which I now realize never existed. :oops: Meanwhile I bought an original MK III manual off ebay and it should be here any day now. It should help me resolve a lot of these unknowns.
 
RennieK said:
There is no sign of a linkage through the inner GB cover so I'm assuming this was factory as it's a matching # trans.
Click to expand...

All MkIIIs were left foot shift, however, the pre-MkIII inner and outer gearbox covers can be fitted to the MkIII gearbox case.
 
want another way to lose a few KG on your Mark 3?

Do what I did years ago.... remove the kick start lever and put it in a box. It is a heavy hunk of metal. No regrets!
 
pkeithkelly said:
want another way to lose a few KG on your Mark 3?

Do what I did years ago.... remove the kick start lever and put it in a box. It is a heavy hunk of metal. No regrets!
Click to expand...
Ha, you must be weighing it with your boot on it. It's 780 gr. but with rubber and fixing bolt an easy 800 gr. but still under a kilo. I'll take my kick start any day over an e-start, it's part of the Norton's charm that moderns just don't have.
,
In the last 2 weeks I've seen 2 metric bikes stall at a traffic light and have to hit the e-start. Guess you don't really notice how often they stall since you never see them kicking.
 
Lightness is Rightness so you'all definitely feel less motorcycle off center mass for more zinging grinning. A Commando should be hard to stall and one kick or rather step restart w/o throttle if it does. One of my meanest=funniest shouts before I leave a gahtering, which is hard to avoid out here, Hey ya know what they say them "Thumb Commensors" are known for, [all heads cocked at WTF I mean, then I step on it for the SNort, "lowering one's IQ" ZoomMMM....

A rule of thumb is 7.5 lb mass off is worth an extra hp in acceleration. Center stand is ~8 lb and can be felt, so left Peel's off with it fractures and made foldable box shape lift to service tires. Of course its shameful immature to operate so ya can really tell that way. Its said even dull pilots can tell a 10% change in performance.
 
You dont even need a battery , so that adds simplicity & lightness . :P :lol: With the 2MC Capacitor . :D

If you DO start it on the Capacitor ; you switch Ign. OFF , Swing over TWICE to charge capacitor ,
position pistons & kickstart . Check for small children & old woman aft . Switch ON and Swing Over .
 
I just bought a '75 Mk Iii electric start but it has had the starter removed. I have just bought a new starter for it but not sure yet if the gears and bits and pieces are in the primary, haven't had time to look yet. If they are not do you want to sell yours?

Tony
 
Hey 737captain, I'm going to hang on to my e-start bits just incase I develop knee problems when I'm older.

slimslowslider, that's the look I'm after! I'll have to keep an eye out for a spare inner case. Having that hump there when you're running a starter is one thing but with the starter gone it looks like an unwanted wart.
 
Thank for the link Brent but $100lbs and shipping is over budget for me right now. I've made a blanking plate that I'll live with till another inner case falls in my lap.

MK III Clarification + convert to kick start
 
You could fit a hollow- can arrangement to the hump for foam wrapped tool storage ,don't laugh ,I've seen it at a rally. :|
 
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