22 year old and my first norton 650 ss :) from england

Yay finally got the cat and fiddle an wet cheshire test ride onboard edited dried up a bit by the time we made it to the cat was cool seeing how the 650ss handled in the wet superb chassis meant just as good as in the dry.
Few things to sort this weekend after I fix my uncles gt750 tomorrow.
Think the whine is of the timing chain so need to check that. Is the mag one tensioned by the same tensioner for the cam one? Gonna go through my manuals in the morning.

Couldn't hear the timing whine clearly till we sorted the rocker spindles an primary chain.

An need to fit the new springs I've ordered for the outer gearbox cover if they show up before weekend.

Exciting though that the carbs are settling in along with the rocker spindles.

Too tight tension on magneto chain may cause AAU to "stick" in advanced position. Should have 1/4 inch up/down slack in chain.

Slick

Cheers Slick it's all starting to add up said to dad it's like the aau was advancing itself sometimes so that an the slight whine which I've been pointed onto being the timing chains make sense now. I'll make sure to check where the timing is at on her before I go adjusting anything. From memory when I had the cover off doing the rocker spindles it looked tighter than that. I didn't want to go disturbing to much on the bike all at one go but now I've got the rocker spindles sussed I'll whip the cover back off and sort the timing chain adjustment. Is it worth replacing the springs on the AAU guys?

What's everyone tending to aim for timing wise on this modern fuel? Running 99 ron although e5 whenever I can get it.

Today's task checking chain tension on my 67' Norton 650SS just sitting down an reading the manuals.

Looks like both are at 1/16th at the tightest spot gonna just get some tip ex an Mark it up to double check. Others points about 3/16th mag chain is quite tight all the way round so that's probably where the noise is.

How cool is that support plate for the intermediate spindle from Norvil love service tools.

Gonna verify what the timing was set to before I go altering anything as it was running great

IMG_20190907_122156_716 by norton.rider, on Flickr

If magneto spindle is off center, the drive chain may exhibit tight/loose spots.

Slick

Know it mentions in the books minimum play does anyone know what the max permissible play is? Just about to check the current timing before I adjust the chains

Had a bit of a mare of a day today on her not actually got to the point of adjusting anything yet.

Think I've been screwing up somewhere along the line.

Wanted to verify the timing where it is at currently.

Mounted degree wheel an pointer to the crankshaft on the primary side found tdc.

Got the measurement in the middle of the dwell.

AAU unit locked in advance.

Fag paper in to 32 degrees it'd come out with a tug but looked like they were shut.

Spent some more time faffing around trying it a couple of times.

Turned the engine so the points from being open at tdc moved anti clockwise and started to shut. Visually looked like they shut at 24 degrees.

Then I noticed a fair few pages on in the manual it mentioned that at full advance the AAU is at 24 degree's.

So question is does the aau need to be removed from the taper to check the timing or will it thow it all out? Know it mentioned removing it to adjust the timing.

Curious where it's actually at before I go adjusting the chains which are on the tight side.

Cheers,

norton_rider said:

Then I noticed a fair few pages on in the manual it mentioned that at full advance the AAU is at 24 degree's.

Click to expand...

24 degrees is the (crankshaft) AAU advance range (so 12 degrees AAU advance).

Cheers mate so If I'm understanding it correctly with the aau locked up advanced the ignition timings actually set at 24 degrees before top dead centre if the point's are cracking open at that reading.

So that's 8 Degrees retarded.

Least I've found something else to remedy she's just constantly getting better an I thought she was performing good at that!

Everyone still aiming for 32 degrees with modern fuel?

norton_rider said:

Cheers mate so If I'm understanding it correctly with the aau locked up advanced the ignition timings actually set at 24 degrees before top dead centre if the point's are cracking open at that reading.

So that's 8 Degrees retarded.

Click to expand...

No. 24 degrees is the (crankshaft) advance range of the AAU from full retard to full advance (or vice versa) therefore if full retard is 8 (crankshaft) degrees BTDC then 8 + 24 = 32 (crankshaft) degrees BTDC full advance.

Sorry mate I meant mines 8 degrees out from where it should be set at 32 degrees? Or am I totally missing the point haha! I'll get my head round it. Shattered now so probably not reading everything clearly.

With the aau locked in advance the points start to open going back towards tdc at 24 degrees before tdc on mine.

So am I right in saying that's what shes actually set at? Sorry if I'm not explaining it correctly.

Looking forward to trying it all with a fresh set of eyes in the morning.

norton_rider said:

I meant mines 8 degrees out?

Click to expand...

If you set it to 32 degrees BTDC fully advanced as you said (assuming 32 degrees is correct) and the range of the AAU is 24 crankshaft degrees (12 degrees AAU) then it isn't 8 degrees out, as 32 minus 24 = 8 so if set at 32 degrees BTDC full advance then full retard will be 8 degrees BTDC.

Here is the full Monte on setting up your magneto.

https://www.accessnorton.com/NortonCommando/setting-up-and-timing-a-k2f-magneto.19685/

Slick

Thanks Guys Just about to get her out again an have another look.

Damn I must have been having an off day yesterday haha!

Just re checked it all making sure not to stop with the spanner just cracking at 32 degrees on both cylinders. Gonna put some slack into the chains mag one is like far to tight then re confirm the timing.

Checked it a few times just to make sure an consistently getting the same reading.

All sorted an back together chains are adjusted to correct spec Tomorrow's job is to replace primary cover an redo oils + start looking at the gearbox springs.

Re; “Fag paper in to 32 degrees it'd come out with a tug but looked like they were shut.”

Exactly what compression ratio are your pistons?

32 degrees is for the old dished 7.5; 1 pistons

28 degrees is for the 10.5: 1 pistons with the 9: 1 in between.

Ignore all the previous posts bar the last one I did haha saturday was a write of for various reasons and distractions. Sunday all went perfect was getting some backlash on the saturday as I was stopping when turning her over oops! Bit of a break an the Sunday went spot on as I remembered about back lashing from the print days.

Just had this discussion over on one of the Facebook groups.

Other dommies were 7.5:1

7.6:1 is the atlas compression ratio they were fitted with the dished or domed pistons whatever term you want to use.

From what I've read up you can buy decomp gaskets lower the compression ratio with 8.9:1 comp pistons for the other bikes.

Norton 650SS was the sports special model shipped with 8.9:1 compression ratio and was specc'd at 32 before top dead centre.
Well that's what it says in my reference material.
Took this info from the following
Original Norton 1967 Brochure.
The book of Norton dominator twins.
Norton twins By Roy Bacon.
Norton P106/P Norton Plumstead Manual.

Mines fitted with the correct 8.9:1 pistons from Norvil for the 650SS.

Can post pictures of the pages if everyone wants?

Confirmed the timing on the sunday and it was set by the previous owner at 32 before tdc which it's been running fine at. I guess he should know he's done 45k miles on it from new.

Hi Tom
Sounds like you are having good fun learning, I got news for you though (IMHO) with ownership of a Norton (or any other old British motorcycle) you will still be learning new things for years to come yet, don't give up , they kept the gray matter working, at least you get good advice on this site!

Burgs

Thanks Burgs yep really enjoying learning that's for sure I think you never stop learning in life, next thing to do is put the new oil in primary back on an then I'm going to fit the new springs in the outer gearbox cover had some for an age just not got round to fitting them.

Confirmed with some experts I trust an with my uncle who I definitely trust when it comes to Norton's 32 before tdc on the 650SS at 8.9:1 with the pistons she's got fitted is the right number so it's staying at that + all the books and my original brochure back it up obv for everyone else do your own research but that's what shes been running at an what it's staying at

Itching to get back out on her so tomorrow I'm gonna be up soon as it gets bright an get stuck in!

One thing's for sure she wont be my last Norton actually weighing up if I sell some of my Japanese classics I've restored what would compliment the 650SS an 68 NV Commando.
88SS another 650SS but with Manx/domiracer stuff on it or a single keep springing to mind I'd love an Inter but think they would be outta reach at the moment.

Good thing is the Japanese stuff in the uk is going crazy at the moment.

An yeah thanks slick that was a really helpful post.