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Discussion Starter · #1 ·
I've replaced my old point system of my 68' trophy with a boyer system and can't figure out how to start the timing. Do I set timing as if there where points, or do I just bring the right piston to TDC? I have the Boyer instructions, but point 16 just says "Set engine to the full advance timing mark on compression".
 

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Full Advance

I've replaced my old point system of my 68' trophy with a boyer system and can't figure out how to start the timing. Do I set timing as if there where points, or do I just bring the right piston to TDC? I have the Boyer instructions, but point 16 just says "Set engine to the full advance timing mark on compression".
The service bulletin, 294 issued in Feb 68, illustrates changes in the way the B (650) engines were referenced for full advance.
However, in all cases this is stipulated as 38deg BTDC.
So in answer to your query, this is the setting, not TDC.

Good luck
 

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Yep, I'm with Rochdale :)

Do you have the slots in the crank, with a small hole behind the timing side (right hand) cylinder at the base, where with a bolt you can locate the fully advanced (38 BTDC), and the TDC positions? My '71 has it, can't remember whether '68 should have it.

Anyhow, I set my Boyer with the engine fully advanced, then first with the red dot lining up through the hole in the Boyer pickup plate, getting the engine to run and then revving to approx 5000 rpm and checking it with a strobe (still with the red dot appearing through the hole). Should work that way.

-Ville
 

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I f I may can I make one small correction.

You should check your final timing adjustment with a strobe via the timing mark on your rotor and not on the Boyer timing plate. Checking the timing that way will only confirm the ignition timing relative to the Boyer's plate. Even if you were out ten degrees, the strobe will still confirm the plate's position.

What you really want to do is to check the timing of the spark relative to the crankshaft position - and by extension the piston's position. This you do with the strobe aimed at the timing marks on your rotor. Ref your bike briefly to 5000 RPM and the timing mark should stay steadily behind the indicator pin.
 

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I stand corrected :)

For some reason I didn't have timing marks on my rotor (at least the type pictured in Haynes).

We did do temporary marks with nail polish, but in essence that's the same thing, right?

-Ville
 

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Discussion Starter · #6 ·
No, I don't the hole to the TDC indicator. Now when I use the timing wheel, am I going for 38 deg BTDC, or half that due to the cam turning half as fast?
 

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Crank degrees

The normal timing references for valves and ignition are always crank degrees.
In this specific instance 38 degrees BTDC is definitely crank.

Good luck.
 

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If I may put in my 5 eggs.
When you use hole behind the barrels, there are two slots in the flywheel.
One is at TDC and the other is the timing mark (38 BDTC).
So initially, you need to find the TDC slot using a stick (long paintbrush handle or similar) in the plug-hole to verify you are in the correct slot. Careful...dont jam the `stick`!
Then put it in gear and rotate the rear wheel backwards to find the 38 BTDC slot. [It may be neccessary to rotate further and then go forwards to take up any backlash]
When the timing mark is central in the hole, the alternator timing mark should look look something like this:

And if you had a Sparx kit, it should look like this:

Then when you start the engine, using a strobe you can adjust the ignition stator (above) for fully advanced on the alternator at high revs...whatever is recommended for your kit.
 

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Caulky,
Many thanks my friend for you "five eggs". With the photos makes perfect sense to my dense head.
I have a 69 TR6 I have been working on for some time. Obviously the cases have been split because I do NOT have the access hole behind the barrels. Then trying to figure the 38 degrees has been troublesome. I have a wheel and such, but you made it pretty clear!

Bryan
 

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Just a quick addition, if a degree disc is used on the exhaust camshaft (points shaft) the fully advanced angle would be 19 degrees, not 38 because its rotation is half as fast as the crankshaft.
 

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Discussion Starter · #12 ·
Okay, So I've set the rotor to 38BTDC, put a new battery in, changed out my old coils, wires and plugs. I still can get the bike to turn over, I've even tried to up it in 2nd. Any help here will be great. Thanks
 

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Presumably, you mean you cant turn the engine over by rotating the rear wheel. Put it in top gear and gently `inch` it. Plugs out?
If the plugs are out, does it kick-over easily?...if not there`s a serious engine problem. You mentioned the valve gaps were tight earlier.
Might be bent pushrods.
Remove the rocker caps, undo the tappet adjusters.
If it still wont kick-over, I`m afraid the head will need taking off to locate the problem.
 

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I suspect he's using the term "turn over" to mean start. I've run into more than one person who thinks and engine that won't turn over is one that won't start, instead of one that won't revolve with the starter. Since we're talking about a kick start bike here, "turn over" does not even really apply.

68TR6C, if you mean it won't start, you should say that to avoid confusion.

I suggest you check for spark with the plugs out. If you have a good hot spark and are sure you timed it correctly and it still will not start, then I would suspect something else, like fuel. If you choke it, do you smell gas? Are the plugs getting wet? Try squirting a little gas into the throat of the carbs with a syringe and see if she'll fire.
regards,
Rob
 

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Discussion Starter · #15 ·
Sorry for the confusion, I meant that the engine wont start. I checked for spark, none. I do have power and ground to the ignition box. I also double checked my wiring and timing. The cylinders are getting fuel, the plugs are wet from trying to kick start the bike last night.
 

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I'm coming in late on this. Here's a link to Boyer help files that should help you work thru your problem. No spark at all leads me to believe you have connected something wrong or there is a bad component. I'm not an expert here but if the system is hooked up right, it should work. http://www.britcycle.com/help.htm

Read thru these help files and make sure you did everything right. I'm willing to bet that you missed one detail that is preventing the system from working correctly assuming this is a new Boyer.
Good luck,
Rob
 

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Sorry i know this is an old thread but I'm trying to swap out for an electronic ignition for a 69 Bonnie. I can't get the old advancer plate out. Any idea of what sort of bolt (diameter / thread) I could use as a puller?
 

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ADVICE ------ Boyer MICRO MK-4 Installation issue! ------- ADVICE would be appreciated !!

While installing the magnetic rotor, I think I may have trimmed the cap head screw that holds down the Boyer magnetic rotor slightly shorter than required; when fitting the rotor (finger tight) with the newly shortened screw, I feel that the rotor is stiff and doesn't rotate freely, its only when I loosen the screw a little, the rotor moves freely, so, with this situation I don't think I would be able to tight the cap head screw firmly in place.
I tried to get a replacement screw without success, I wonder if it OK to file down/shorten the (coned) back of the rotor so its not jammed.

Thanks
 

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You do realise that the part sdown by the bolt o
ADVICE ------ Boyer MICRO MK-4 Installation issue! ------- ADVICE would be appreciated !!

While installing the magnetic rotor, I think I may have trimmed the cap head screw that holds down the Boyer magnetic rotor slightly shorter than required; when fitting the rotor (finger tight) with the newly shortened screw, I feel that the rotor is stiff and doesn't rotate freely, its only when I loosen the screw a little, the rotor moves freely, so, with this situation I don't think I would be able to tight the cap head screw firmly in place.
I tried to get a replacement screw without success, I wonder if it OK to file down/shorten the (coned) back of the rotor so its not jammed.

Thanks
You do realise that the magnet plate only rotates when the engine turns over ? Loosening the bolt it will not be locked onto the taper. The bolt has to be tight.
 
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