Knocking / rattling inside primary drive case + backfire

Ok, I think I've found my missing 4mm. Looks like the clutch location circlip is completely missing - assuming it goes in this slot on the clutch shaft?

Knocking / rattling inside primary drive case + backfire
 
Amazing! Thanks for confirming. Kinda chuffed I worked that one out for myself. I'm learning - hah!

Also amazing the bike ever worked to be honest.

EDIT: The more I think about it, the more nervous I get about the fresh looking gaskets all over the engine, although I have heard it running and the engine itself sounds OK albeit previously with a backfire.

EDITEDIT: I'll be checking the brakes before riding!
 
So, thinking about the implications of this - the chain alignment would have been out by 4mm or so. This maybe caused the sprocket to work it's way off the taper OR maybe the 6mm collar on the rotor shaft was a bodge spacer to make up the difference.

Anyway, new parts are on order and should be here in 24-48hrs.
 
Reminder of the circlip upgrade, the alternative is stronger but requires fettling to fit.

order in circlip (or 2 ) 06-8072 as it is thicker to fit into the main shaft circlip slot. In true British fashion you will have to fetter it in order to drop into the slot fully home. It's thicker so I rubbed it a bit thinner using a circular motion on emery paper until it dropped into place with a couple of small persuasive taps with a small flat-faced punch.

Clutch locating circlip on mainshaft (2013)​

www.accessnorton.com
www.accessnorton.com



Lets hope the moron who worked on the primary did not work on the rest of the engine, if he did I would be inclined to take a look behind the timing cover and under the rocker covers..
 
It's hardly any wonder the thing was knocking with it loose at both ends! ;)

M-Hawk said:
So, thinking about the implications of this - the chain alignment would have been out by 4mm or so. This maybe caused the sprocket to work it's way off the taper...
Click to expand...

If the rotor nut had been capable of being fully tightened then there'd be no way for the engine sprocket to loosen from the taper.

M-Hawk said:
OR maybe the 6mm collar on the rotor shaft was a bodge spacer to make up the difference.
Click to expand...

I'd say that was a bodge possibly because the nut wouldn't fully thread onto the crank.
 
@M-Hawk, despite my jocularity earlier in the thread I was concerned that after shelling out your money on this bike you would be faced with a ruined crank. Thankfully its not the case and I for one am very pleased for you.

I’m not sure if you checked it already, but as L.A.B. mentioned earlier, I would definitely check that when installed, the woodruff key is not taller than the keyway, as that would obviously stop the sprocket seating properly on the taper, and may not be evident until you’re out on the road.

When you re-install the clutch, pay particular attention to the thick spacer behind it. One side is recessed in order to captivate the circlip.

👍 👍 👍
 
When our hero mentioned no crank play, did that mean end float as well? Thought there is supposed to be a measurable end float spec for crank?
 
Looking at the witness marks on the inner chain links side plates (pictures in post #202), glad you found the cause of the sprockets being out of line.

-George
 
Wonderful. New nut, circlip a little measuring and you'll be home free! With the sprocket snug and the circlip installed along with the thick washer, put the clutch on and use a straight edge to see what it will take to align the two sprockets. Hopefully, the clutch shims you have will do it. Get it close realizing the when the engine sprocket is torqued down it will move in a little more. Ain't no rocket ship - a few thousandth off won't hurt but try to get them aligned - the crank moves in and out a little so perfection is a moving target. Then pull them off, put the chain on and rebuild the primary.

If you haven't already done the check/fixes for the inner chaincase, but that before finally building the primary.
 
M-Hawk said:
Cheers @cliffa Mo, it was funny :) Thanks - I’ll be sure to check those things on reassembly. Great tips.

@Tornado I’ve not checked end float. Good point.
Click to expand...
Tough to check on an assembled engine. I'm 99.9% sure there's nothing wrong there. If you have 0.000" and the crank turns freely, you're OK (the crankcases expand when hot). At one time Norton said 0.005"-0.015" but later changed to 0.010"-0.024". I normally see between 0.010" and 0.020" with slight differences at different years. There have been a lot of opinion on this over the years and this is only my opinion - basically nothing to think about if the crank turns freely.
 
Ok thanks. I’ll not worry about end float.

Not quite home free but getting there. I still have the stator clearance issue, potentially.

Then, when the primary is done, I’ll be on to the backfiring issue. Hopefully resolved with good timing and sorting out the right side exhaust (a story for another day and probably a separate thread!)
 
marshg246 said:
Tough to check on an assembled engine. I'm 99.9% sure there's nothing wrong there. If you have 0.000" and the crank turns freely, you're OK (the crankcases expand when hot). At one time Norton said 0.005"-0.015" but later changed to 0.010"-0.024". I normally see between 0.010" and 0.020" with slight differences at different years. There have been a lot of opinion on this over the years and this is only my opinion - basically nothing to think about if the crank turns freely.
Click to expand...
I thought you could put a dial gauge on the end of crank and just push/pull crank to measure float? No or excess float would be worrisome...indicating more issues within from previous bodges.
 
Sounds like the Bodge of all bodge jobs. The nut is gunked so much it can't torque, some genius puts a spacer and it still doesn't tighten the pulley.
Improper woodruff keys, no Clutch circlip... What a mess.
I'd probably do all new hardware. Check the inner clutch bearing while it's apart. Should be nice and smooth rolling.
 
Tornado said:
I thought you could put a dial gauge on the end of crank and just push/pull crank to measure float? No or excess float would be worrisome...indicating more issues within from previous bodges.
Click to expand...
You certainly can with only the crank in the cases. It gets much harder to get it to move with a built cold engine. I have done it by turning the engine while pushing on the crank end but usually cannot get movement just pushing.

IMHO with zero end float and a crank that turns easily there is no issue. 0.024" is the high end of the tolerance. So, does that mean that the engine won't run at 0.025"?

I agree that with all the other stuff, anything is possible but I doubt that end float is going to be a problem.
 

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