New Norton knocking help please

Motown1 · Jul 2, 2020

olympus said:
When you say away from direction of rotation..
To Retard the ignition you turn the points/EI pick up mounting plate with Camshaft rotation
To Advance you go against camshaft rotation
In the case of the Norton to retard the timing you turn the plate anti clockwise

Thank you.

Motown1 · Jul 2, 2020

Steves said:
This crossed my mind also, are we talking knocking or lugging?

Pinging

FastFred · Jul 2, 2020

Never known plug gaps as high as 35 thou, reduce them to 25thou but sounds like ignition timing

DogT · Jul 2, 2020

Some Citgo stations handle racing fuel. I've been using 110LL, no knockin (pinging or pre-ignition) here. But like others have said, it's probably the timing. The blue stuff runs great, I use it in all the 2 stroke yard equipment except the mower which runs fine on regular.

Motown1 · Jul 2, 2020

Thanks again guys for all the reply’s!!! You have all been a wealth of knowledge that I will put to use. Going to set timing Friday...shit is always popping up that distracts me from getting her done. I will let you know what I find out and if it’s gone. Thanks again. Nate.

ashman · Jul 2, 2020

FastFred said:
Never known plug gaps as high as 35 thou, reduce them to 25thou but sounds like ignition timing

I was thinking the same when I read that, ran a Boyar EI most of my Norton life and the plugs were always set at 25thou, now running the Joe Hunt Maggie the plus are set at 18thou as pre JH instructions, I thought 35thou was a wee bit to much.

Ashley

Motown1 · Jul 3, 2020

Motown1 said:
Throttle stop to set ground idle, Like a Mikuni carb dial you turn with a screw driver or hand. The Amal Mkii

I found it. as stated before, I’m used to mikunis big idle ”throttle stool screw. Thanks much.

Motown1 · Jul 3, 2020

Ran bike up to 4500 and timing was around 36 but then moved timing plate CC then would go to 40
.

Bernhard · Jul 3, 2020

maylar said:
You need to check the timing with a strobe. 29° BTDC @ 4000 rpm or 31° @ 5000.

It should be 28 degrees on FULL ADVANCE, surely?

maylar · Jul 3, 2020

Motown1 said:
Ran bike up to 4500 and timing was around 36 but then moved timing plate CC then would go to 40

Something's not right. Rotating the sensor plate CCW should decrease the advance. And 36° @ 4500 is way too high.

maylar · Jul 3, 2020

Bernhard said:
It should be 28 degrees on FULL ADVANCE, surely?

Boyer MKIII analog calls for 31° @ 5000. It's been determined empirically that 29° @ 4000 will get you the same results.

Motown1 · Jul 3, 2020

Gonna try again. White dots are lined on plate and correct Tdc * the directions say to roatate rotor if cannot time correctly

Motown1 · Jul 3, 2020

Shits at 40 at 4000

Motown1 · Jul 3, 2020

Running out of retard slot on timing plate

Bernhard · Jul 3, 2020

So, whats the differance between a 750 Commando and a 1960s Atlas?
I set my Atlas up at 28 degrees on 10:5 to1 pistons and never had any pinging, unlike a 500 single which I had which did, because an idiot of a petrol pump attendant filled it up with the wrong octane gas, resulting in a chewed up piston.
31 is too far advanced unless you still have those dished 7.5 :1 pistons .

maylar · Jul 3, 2020

40 will hurt your motor.

Bernhard · Jul 3, 2020

IMO you are going the wrong way, full advance at 5000 rpm should be 28, and when its retarded possibly 31, at 1000 rpm.

maylar · Jul 3, 2020

Bernhard said:
31 is too far advanced unless you still have those dished 7.5 :1 pistons .

Stock timing with points was 28° @ 3000. The advance was full on by 2800 IIRC. Electronic ignitions impliment advance electronically, and the Boyer specs 31 @ 5000.

Motown1 · Jul 3, 2020

adjusted stator plate to max retard and it’s at 38* Boyer directions say adjust stair rotor to get more retard

Blewdy Yaink · Jul 3, 2020

Motown1 said:
adjusted stator plate to max retard and it’s at 38* Boyer directions say adjust stair rotor to get more retard

OK, you're not going to like this suggestion, but I wonder how many degrees the timing plate that aligns with the mark on the alternator is incorrect. I say "how many degrees" rather than "if" because I don't think I've ever seen one that's perfectly accurate. Checking is a little fiddly and takes a while (and is probably impossible without a degree wheel and care to get it right), but every Commando should be checked. On a stock (non-Combat) engine with points, a few degrees probably didn't matter but with unknow compression and an electronic ignition, you can easily get to combination where accurate ignition timing is critical.

New Norton knocking help please

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