Boyer issues? Or not?

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Coolhands

Coolhands

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In this edition of “If It’s Not Broken I’ll Fix It Until It Is”:

Took the bike down to remove the primary to replace transmission and crank seals, put a timing wheel on to check the accuracy of the timing marks (they were good).

At first I had some pops but couldn’t get it started.
New battery 13v
New rotor and stator
Good compression
Mikuni with same settings when it was running
Timed at 31 degrees with rotor flat and the mark in the anti-clockwise hole.
13v at coil and jumped negative battery post to Boyer white wire.

Have spark on both cylinders when grounded on kicking over, turning on ignition, and when scratching the black/white and black/yellow (red this might not happen but can sometimes?)
Absolutely nothing when trying to start. No pop… nothing.

Pulled the carb just to make sure the idle circuit was clear and the slide was shut

Is it possible the Boyer box can be fried and sending bad signals?

Pretty frustrated. Set of amals and points sitting on the bench is my next step if you gents don’t have any better ideas.

Compression, fuel, spark, right?

Any ideas? As per usual I feel like I’m missing something simple.
 
I think I read that a Boyer ignition when unplugged will take a "Few" kicks to get signal. I often think points systems start easier, but after that electronics are best.
 
Yeah, I’ve kicked it more than a few times. This was a first or second kick bike when I took it down to fix the oil leaks
 
Could be you've dislodged an electrical connection during other work.
Try by passing ign switch and go direct to boyer power (ok maybe a simple toggle switch in line just as an emerg shut off).

Could timing have been set to the wrong crank rotor mark (180 deg away from correct mark)?
 
Tornado said:
Could timing have been set to the wrong crank rotor mark (180 deg away from correct mark)?
Click to expand...

For that to happen when the ignition was apparently working normally beforehand then the Boyer rotor would have to be removed and reset incorrectly but there's been no mention (so far) of the Boyer rotor having been removed and replaced at any stage of the work done on the primary side so the ignition timing shouldn't have changed.
 
As with all Boyers check the wires to the stator plate. Vibration causes the copper strands to shear within the insulator, so not visible. Connect a multi meter set on ohms to each and check continuity while wiggling the wires.
 
cliffa said:
As with all Boyers check the wires to the stator plate. Vibration causes the copper strands to shear within the insulator, so not visible. Connect a multi meter set on ohms to each and check continuity while wiggling the wires.
Click to expand...
Thanks for this. 140 ohms on the plate and 70 per coil, but I didn’t wiggle the wires. I’ll check this next. Also found a suspect connection I’m going to rewire.
 
Are the spark plugs wet with fuel?
My Boyer equipped bikes start first kick - as do Pazon and Trispark
 
Coolhands said:
In this edition of “If It’s Not Broken I’ll Fix It Until It Is”:

Took the bike down to remove the primary to replace transmission and crank seals, put a timing wheel on to check the accuracy of the timing marks (they were good).

At first I had some pops but couldn’t get it started.
New battery 13v
New rotor and stator
Good compression
Mikuni with same settings when it was running
Timed at 31 degrees with rotor flat and the mark in the anti-clockwise hole.
13v at coil and jumped negative battery post to Boyer white wire.

Have spark on both cylinders when grounded on kicking over, turning on ignition, and when scratching the black/white and black/yellow (red this might not happen but can sometimes?)
Absolutely nothing when trying to start. No pop… nothing.

Pulled the carb just to make sure the idle circuit was clear and the slide was shut

Is it possible the Boyer box can be fried and sending bad signals?

Pretty frustrated. Set of amals and points sitting on the bench is my next step if you gents don’t have any better ideas.

Compression, fuel, spark, right?

Any ideas? As per usual I feel like I’m missing something simple.
Click to expand...
Spray a whiff of starting fluid in there.
Pop? More fuel is needed.

Pull each plug, dribble a teaspoon of gas down there.
Start & run 1-3 seconds?
More gas.
I use a squirt bottle. Hey, if it was good enough for Austin Coyle, good enough for me.
Boyer issues? Or not?
 
Coolhands said:
Static timing set to mark thru counter clockwise hole at 31 deg BTDC on the compression stroke.
Click to expand...
Wiring appears OK as you get spark, so I would suspect the static timing is a bit off.
There was some initial sputtering going on for you and now nothing, no kickback, so it doesn't seem to be too advanced, timing may be retarded slightly.

I would try marking the existing boyer stator plate position (not the inner one with the magnets on it) against the side of the case timing well and advance the boyer stator plate a tiny bit at a time clockwise to advance it and see what happens.
In between the time the ride gets flooded with fuel :) I would fiddle with the stator plate advance or retard until I get a reaction.
Boyer stator counter-clockwise to retard, stator clockwise to advance.
 
FWIW- I just went through a situation where bike was getting harder and harder to start and would occasionally kick back. It was formerly a 1 or 2 kick starter. Found the power wire crimp connector under the tank for the Boyer hanging on by 1 strand.
 
I'll make a guess that the wrong rotor timing mark was chosen for the set up of the boyer. Effect is it fires when the pistons are at Bottom dead center.
Cheers
 
Steve W. said:
I'll make a guess that the wrong rotor timing mark was chosen for the set up of the boyer. Effect is it fires when the pistons are at Bottom dead center.
Cheers
Click to expand...
 

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Images you posted say it should start if nothing else is faulty. It is certainly within range on the static timing. Puzzler it is.

Did you try new spark plugs? Sounds like a BS idea, but sometimes that is a cure for hard starting. I've had plugs that show spark, but the motor was still hard to start until I installed new plugs.
 
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