Timing with a boyer

jesterday · Jul 15, 2014

I am having an issue with timing, or at least I think I am. I time the bike to be 31 degrees btdc static according to the factory degree marker on the primary cover. I know these aren't always accurate. And I know you can't accurately time a boyer statically. The issue I am having is when I use my timing light, it shows it idling around 31 degrees, when I Rev it up, it goes all the way off the wheel, somewhere around the 50 degree mark. am I crazy? Or does my timing light have some weird auto advance thing? I would get a degree wheel but it isn't something really available in my town and I have no clue how to use it anyway.

The other thing I am wondering is could my boyer box possibly be damaged causing the weird advance in ignition?

concours · Jul 15, 2014

Any chance you're using the wrong timing mark? Had a thread recently... :?: ignition-timing-t19692.html

auldblue · Jul 15, 2014

Hi
May I ask does it start ok, and run ok.

J

jesterday · Jul 15, 2014

It starts and runs OK, I foul a lot of plugs, I am using a js single carb. I have tried every needle jet that Jim has trying to lean it out and I think it is there. So my old man thinks it is not timed perfectly and I am just not burning all the fuel or something. I am at a loss. I am spending $10 every 20 miles on plugs.

I am reading the proper timing mark I have it marked so it is easily identifiable.

texasSlick · Jul 15, 2014

The automatic advance unit should be wedged in the fully advanced position when setting timing to the factory spec (28 to 32 degrees depending on model). If you failed to wedge the AAU full advanced, you could get the results you posted. I just do not understand how you could get the engine started with that scenario.

Slick

PS. You can download a degree wheel from LAB's technical data at the top of the Forum page.

auldblue · Jul 15, 2014

Hi

Have you did a plug chop. I had a fair bit of bother myself mikuni , but I also had oil issues . Plugs the same as yourself ,

I know some carbs can be a bitch , but sometimes a plug heat change does help .

J
Texas

Could you run that one past me again?

concours · Jul 15, 2014

texasSlick said:
The automatic advance unit should be wedged in the fully advanced position when setting timing to the factory spec (28 to 32 degrees depending on model). If you failed to wedge the AAU full advanced, you could get the results you posted. I just do not understand how you could get the engine started with that scenario.

Slick

PS. You can download a degree wheel from LAB's technical data at the top of the Forum page.

AAU is discarded when the Boyer is fitted.

texasSlick · Jul 15, 2014

concours said:
AAU is discarded when the Boyer is fitted.

Thanks for that info, Concours.......if it were still fitted by some chance, would that not explain the results jesterday reports?

Slick

auldblue · Jul 15, 2014

Slick

If it was fitted it would have points ,the rotor fits into the aau bolt hole to set the boyer.

J

texasSlick · Jul 15, 2014

auldblue said:
Slick

If it was fitted it would have points ,the rotor fits into the aau bolt to set the boyer.

J

Ah! such a possibility just occurred to me, but you beat me to editing my post. Sorry my ignorance of Boyers and other EI's is showing. Such is the happy and sheltered life of having a magneto!

OK then, can anyone explain jesterday's weird timing?

Craig · Jul 15, 2014

IF both plugs are fouling maybe you still have a carb . problem and your timing is close ,if as you say bike starts and runs it can't be far off. Do those carbs have a cold start device , enrichment circuit ? Is it in closed position for sure ? Might be something like that eh ?
Craig

auldblue · Jul 15, 2014

Craig said:
IF both plugs are fouling maybe you still have a carb . problem and your timing is close ,if as you say bike starts and runs it can't be far off. Do those carbs have a cold start device , enrichment circuit ? Is it in closed position for sure ? Might be something like that eh ?
Craig

I know nothing about that type of carb ,what about a plug chop.
The degree wheel only goes up to 40 ish
J

JimC · Jul 15, 2014

As for timing, TDC needs to be established. Then a timing mark can be scribed using a degree wheel to find the desired degrees advance. As for static timing a Boyer, I'm not sure that can be done. You can line up the holes and dots on the Boyer stator plate, but that's only ballpark. IIRC, the Boyer instructions call for dynamic timing with a timing light.

Just a WAG here, but it really sounds as if the timing may be in the ballpark.

auldblue · Jul 15, 2014

JimC said:
As for timing, TDC needs to be established. Then a timing mark can be scribed using a degree wheel to find the desired degrees advance. As for static timing a Boyer, I'm not sure that can be done. You can line up the marks on the stator plate, but that's only ballpark. IIRC, the Boyer instructions call for dynamic timing with a timing light.

Just a WAG here, but it really sounds as if the timing may be in the ballpark.

I spoke to mick hemmings about this and all he said was set it up with the marks in the primary .start it ,
warm it up, and get the strobe on it and it'll be right. " no prob mick "

I agree the timing is in the ballpark, at least his exhausts are not glowing.

J

kerinorton · Jul 15, 2014

jesterday said:
I am having an issue with timing, or at least I think I am. I time the bike to be 31 degrees btdc static according to the factory degree marker on the primary cover. I know these aren't always accurate. And I know you can't accurately time a boyer statically. The issue I am having is when I use my timing light, it shows it idling around 31 degrees, when I Rev it up, it goes all the way off the wheel, somewhere around the 50 degree mark. am I crazy? Or does my timing light have some weird auto advance thing? I would get a degree wheel but it isn't something really available in my town and I have no clue how to use it anyway.

The other thing I am wondering is could my boyer box possibly be damaged causing the weird advance in ignition?

I suspect if you can start it and run it, the timing must be close. if you want to check the timing mark is correct, you will need to work out how many mm piston travel back from TDC, the TDFC mark will align with 28 Degree mark. That would be the only proof of that timing mark being in the right place, or failing that, take the primary cover off and establish where tdc is, and put a mark on the inner timing cover where this lines up. Then run your engine with the timing light an watch what happens.
I thought I was having problems with my 850 one time so I got my son to help check the timing, and hold the bike still. It was about 31degrees or so with the Boyer so I left it alone.

I also run BP6EY or N9YC plugs in both bikes. the listed ones are too cold for normal use. [ unless you flog the shit out of it like all the idiots did when they were new. Norton had to cater for the Idiots first you know.

gripper · Jul 16, 2014

The timing marks will jump about all over the place if you are strobing it on the centre stand. Get a mate to operate the throttle with the bike off the stand while you pray to the strobe god. If you have re-routed the wires from the boyer pick-up coils and/or replaced them with some solid wire it will screw your timing up big time. Might start ok but will run badly. If you had that much advance, if and when you got it started your exhaust would be glowing red in seconds. Don't ask me how I know but it cost me a pair of pistons.

commando6868 · Jul 16, 2014

gripper said:
The timing marks will jump about all over the place if you are strobing it on the centre stand. Get a mate to operate the throttle with the bike off the stand while you pray to the strobe god. If you have re-routed the wires from the boyer pick-up coils and/or replaced them with some solid wire it will screw your timing up big time. Might start ok but will run badly. If you had that much advance, if and when you got it started your exhaust would be glowing red in seconds. Don't ask me how I know but it cost me a pair of pistons.

Just curious, how does strobe timing on the center stand make the timing marks jump all over the place? I put a mat under the center stand to stop it walking around, and have timed it that way a few times, no problem. It is easier to have someone else operate the throttle while you do the strobe. it only takes a couple of seconds of revving to check the mark.

Timing with a boyer

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