Timing help

I was hoping someone could offer some help...

Backstory: I have a '74 MkII, that is a recently resurrected barn find. The top end was rebuilt, and while we were at it, I got a single Mikuni, and Boyer Mk IV for a little more reliability (on recommendation from many of the local Norton folks). I didn't put the EE in myself; a local vintage bike guy I know did the work. I got it back and it was running like a champ for about 200 miles, no issues whatsoever - it would start consistently on first or second kick. I took it to work this past Monday, and on the way home, while I was stopped at a light, it died on me. Long story longer, I figured out that the ignition stator plate loosened up (and it looks like the black/yellow wire is melted a bit). I managed to fiddle with it and get it started, but I can't seem to get it to run right - to start, I need to give it throttle in addition to the choke, and it takes a good 10-12 kicks for anything to happen, along with some backfiring, which can't be good. Also, I turn the key in the ignition, and it usually sparks a backfire after a start attempt. I called the person who helped me, and he told me I shouldn't need a timing light to get it working again, he just said go through the instructions...but the instructions say to use a timing light, which I don't have. Has this happened to anyone, and can anyone offer some advice on fixing this? Do I need a timing light to get this back into good nick? I really don't want to damage this engine by doing something wrong...

Thanks for any help you can offer.

Sure sounds familiar to me though so many things can give same symptoms.
My guess is the trigger leads have lost copper connect inside
insulation. Fires as long as vibration enough to jiggle
some intermittent conduction at any random point in the stroke.

Also might want to kick over a few times with key on but plug wires
off to charge with mixture, put leads on plugs
then go over wires tugging and jerking
and bumping and flicking to see if a back fire, then focus on
those wires for inconsistent conduction. Doing this in dark
and running can be educational too.

To time to start, follow instructions and note-temporary mark
stator position and creep it up or down till starts then
diddle stator for steady-responsive idle. Go for a ride and see if
properly responsive w/o detonation or stalling,
then
get a separate battery to power the timing light and note-mark
where the timing degree wheel reads and note-mark where
the stator should stay set in future.

hobot

one, is battery fully charged, your boyer demands this

two, a likely culprit is an intermittent ground, check all grounds

Take the plugs out, leave the plug wires on, in dark garage turn ignition on and have an assistant hold a plug against the head while you kick it over,
you should see the plug spark, if so good, check each plug this way, if no sparking when kicking get back to us here

It is a known weakness of the wiring to the Boyer stator plate that they can break off on the soldered joint or the spade connectors wriggle loose. That it should happen so soon on yours is disappointing. The cure is to 1st cehck the spade connectors. If OK, then its further into the soldered joint. Disconnect the black / yellow and black / white pick up wires, remove the stator plate and very carefully examine the joints. If neccesary apply additional fresh solder, but be very careful not to blob it or overrun.

Resetting the timing static is pretty easy. 1st remove the fuel tank and take off the inlet rocker cover. Remove the spark plugs. Remove the front inspection cap on the primary cover and observe the degree plate visible inside. Rotate the motor by engaging 2nd or 3rd gear and turning the back wheel in the forward motion. This assumes you have kept the main stand? If not prop up the frame so the tyre clears the floor. As the wheel turns the engine will turn. Look for either the right or left inlet valve descend and then ascend. As the valve is coming up, its going onto to compression prior to firing that cylinder. Don't allow the valve to go entirely up to its rest.

Now go peek inside the timing hole in the primary. The alternator rotor has 2 opposite vertical slots, of which one will begin to line up with 30 degrees. That is 30 degrees before Top Dead Centre (where the piston stops and goes down on the firing stroke). Roate the back wheel to and fro until the alternator rotor slot mark lines up with 30 degrees. Try to keep it between 25 and 30 for static setting, don't go higher than 30.

Now look at the timing case. The winged magnetic ignition rotor should be horizontal, that is in line with the Norton logo on the timing cover. Take the plastic stator plate and fit it so the slotted adjuster holes top and bottom are centralised. Now you will see that there is a small hole on the left side of the plastic stator plate. Peek inside and you should see the middle of a magnetic wing.

That is the static timing. The engine should start and run OK. The dynamic timing is a strobe light to check if the advance is within limits. The slots on the timing stator plate allows advance or retard to be finely adjusted.

Check the Boyer website for product instructions if you have any difficulty. Also do a check as others have advised on the volts in your battery, Boyers are fragile under 11V.

Mick

highdesert said:

Take the plugs out, leave the plug wires on, in dark garage turn ignition on and have an assistant hold a plug against the head while you kick it over....

Click to expand...

Not sure I'd want to be holding onto a plug wire while 40K volts surges through it....but it would give me a GREAT incentive to make sure the thing is truly grounded...!

Don't worry no one gets a 40K shock from Commando spark plugs,
takes compression of mixture at the plug gap to build resistance to
reach 40K, so only a few 1000's Volts will be felt.
But its a timed tested way to know if hi voltage pulse making it that far.

hobot

well, by wife has no problem holding the plugs against the head while I kick it over, don't know why you would.

Thanks everyone for the advice - I fiddled with it a bit more last night. I did get it started (needed new plugs because the ones I had in it were oil fouled) a couple of times, but it doesn't run great, and is even harder to get going on less than 5 or 6 kicks, so I think it's off to the auto parts store to get a timing light...

I'm just hoping nothing was damaged with all the backfiring.

Beware of the timing scale. It has proven to be erratic in many instances

get the piston as close to tdc with a probe or dial indicator inserted thru the sparkplug hole. Then eyeball the scale and extrapolate where o degrees would lay on the scale if the scale extended that far. On mine it was off 1/8"-3/16".

The proper way to do this is w/ a degree wheel

I. Got mine in the ballpark and then advanced in small increments to get best running. If he's not pinging and plugs aren't burning you should be ok.

Assuming that your installer put the rotor on according to instruction, you can follow standard procedures to bring it back to good runner. If not, you can either back up and start for scratch, or mark the plate and move it slightly in one direction until it starts and run ok or if it get worse. If the later, go back to the mark you made and go the other way. Once running , you will need to time it with a strobe to 30 btdc.

oem points or the Trispark are way easier to set up statically, the trispark especially since it has an LED that will illuminate when the spark would occur. So you just set the Alternator rotor to the max timing setting - say 30 degrees, and rotate the Trispark stator until the led lights. Same with points but there's no LED.

I suggest you check the alternator rotor timing mark with a degree wheel and a dial indicator or piston stop to be sure the mark is accurate. You can download a degree wheel and print/cut it out/attach it to the crankshaft. The marks on my 850 were less than 1/2 degree off but, as noted, others have shown considerable variation. Until you know the mark is correct, you have no idea WHAT the actual timing is. OTOH, as noted, in the old days timing was commonly set by advancing it until it pings and then backing off two degrees. Sounds crude but works fine on the non-computer controlled engines of that day, of which the Commando is certainly one of! Not all engines of the same make/model like the same timing settings so you can usually do better than setting "by the specs" and the "advance till it pings, back off a couple of degrees" may get you better performance than the stock settings. I have seen two identical car engines prefer differences as much as 6 degrees in max timing for best performance.

If you are setting up an ignition on a non computer-controlled engine on a dyno, you keep advancing the timing until either it pings or the power drops off then you typically drop the timing back 2 degrees. The stock specs are a good starting point but that's all.

Just added this: One of the limiting factors re advance for most of us is kickstarting. You want as little advance as possible when starting or you will get kickbacks. This automatically limits the total advance you can dial in even if the engine will accept it because as you advance the max setting, you are advancing the starting setting.

Im new to this also and putting a list of tools to order.Will any dial indicator work for these tests or is there an adapter for the sparkplug thread?

It's funny, I've worked on dozens of Commandos, 90% of which had Sparx ignitions (10% Boyer), and NEVER had an issue with the timing scale being incorrect with reference to the alternator rotor timing mark.

Of the ones that had Boyers, all but 2 were replaced with Sparx and have had only ONE return (failed stator plate and disintegrated rotor magnet, both on the same bike).

The Tri-Spark has a superior electronic design; but in degrees of difficulty, is only VERY SLIGHTLY easier to set up.

Luck of the draw to get a Commando with time scale accurate.
Best way to set curve for me agrees with the above, ignore
all manuals and instructions, diddle timing till back fires-kicks back
on starting then retard till is don't. Then use time light to see
where it should be set in future.

Correct timing by plug chop, if ya can even do that on new gasoline,
is to see the thermal stain on hook electrode to be just a tad
closer to the plug rim near the 90' bend of electrode.

Correct timing will make sounds just a bit less deep sharp bark
than slightly too much advance.

hobot

"Best way to set curve for me agrees with the above, ignore
all manuals and instructions, diddle timing till back fires-kicks back
on starting then retard till is don't. Then use time light to see
where it should be set in future. "

Interestingly, the "old school guys" feel the same about torque settings. The old story is that torque settings for engines were published after a mechanic with lots of experience put an engine together with standard wrenches/sockets. Then somebody checked with a torque wrench to see what the torque settings happened to be and then published those as the torque settings for the engine.

Mike, good point on torque by innate feel - which might have saved
the timing lesion that started this post, time plate loose fastener.

Only place Norton factory used torque wrench was the rod bolts
and even that is misleading compared to measuring bolt stretch.
Alas can't measure this but on rod or crank bolts so back to
tightening beyond what feels comfortable or use loctite
or tabs to prevent innate loosening tendency.

I've had way more damage from too loose torque
put in just a bit above manual list and comfort strain,
than seemly over tightening.
Funny its the opposite to ignoring the manual fluid levels listed.

hobot

Is there a specific dial indicator for aircooled cylinders? I want to find TDC using the piston and a degree wheel rather than trusting the markings?

speirmoor said:

Is there a specific dial indicator for aircooled cylinders?

Click to expand...

Not that I'm aware of?

speirmoor said:

I want to find TDC using the piston and a degree wheel rather than trusting the markings?

Click to expand...

So, make a "piston stop"?

And here's how to use it, as posted by Ron L in a previous thread:
post41831.html

Ron L said:

A piston stop is a solid stop that is usually made from an old spark plug with the ceramic removed. A bolt or rod is welded into it and the end rounded to prevent damage when in contact with the piston. The device is screwed into the spark plug hole and the engine rotated slowly forward until it stops, the degrees read from the wheel, then the engine is rotated backward until it contact the stop again. The degrees are read from the wheel and TDC is exactly between these two readings. Remove the stop and rotate the engine to the determined TDC reading and you can make a reference mark on your alternator rotor and primary to allow you to readily find TDC in the future.

Click to expand...

Remember on the commando stator there are two marks. You need to identifify TDC and use the corresponding mark.

Well the torque settings story is probably a load of crapola. Proper torque is determined by three things: desired clamping force, the fastener in question (size, grade and thread) and the material the fastener is threded into.