Author Topic: Stalled on the road. Now wont start.  (Read 7073 times)

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on: August 26, 2017, 09:12:14 pm
As the title says: It died on the road, and now wont start. This is what happened: Was in 4th gear, somewhere between 5500-6000 rpm (the needle fluctuates so much at that point its hard to tell). So, I noticed I was beginning to lose power, and had suddenly slowed down to about 60 mph. The engine was skipping the thumping....Foolishly I tried to give more gas and kept at it for a few seconds. No luck. It continued to slow down with real loud popping in the exhaust, and came to a halt. My buddy riding behind me saw sparks/flames shooting out the exhaust.  Trailer it home from there.

Testing so far:
1. Fresh gas, carb clean
2. Battery at 13.2 V
3. compression : 120 psi (Ace kit)
4. sparks on kicking

Does not start. I would like to test the coil (bosch blue coil) and the ignition system: Boyer. Where do I start?


Bullet Whisperer

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Reply #1 on: August 26, 2017, 09:25:03 pm
Perhaps the ignition timing has slipped?
 B.W.


Adrian II

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Reply #2 on: August 27, 2017, 12:56:42 am
Possible!

I had this happen on a BSA B40 once, the Boyer's magnetic trigger plate came adrift. Unlike the Lucas a/r unit for the points assembly, which had a nice ground finish on the taper to help it sit securely (in the camshaft, in the BSA's case), the Boyer piece had a turned rather than ground taper which I suspect would have made a less secure join, the turning marks being noticeably ridged. Not having seen more recent Boyer ignitions I don't know if this is still the case.

A.
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Yamahawk

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Reply #3 on: August 27, 2017, 01:57:14 am
Well, your problem does sound like it is ignition related. I would check the Boyer plate that resides behind the round ignition cover, and make sure it hasn't vibrated loose, or even lost a post in there. recheck all your electrical connections to the Boyer module, probably installed in the left hand side box. Also check the wiring to see if any of it is rubbing on the box or frame, and has made a short in this fashion. If this looks ok, check your battery connections and follow the 12v red wire to see if there is any open circuit in the positive path. Electrical problems can be hard to pinpoint, so use your ohm meter to determine connectivity, and voltage paths to all you ignition circuits. And hopefully, you will succeed! I have had a wire break inside the insulation, and would make intermittent contact as the bike was running. That was hard to trace...  :)
Charlie
Think about the circumstances of your call...Not many were wise by human standards, not many were powerful, not many were born to a privileged position. But God chose what the world thinks foolish to shame the wise, and God chose what the world thinks as weak to shame the strong. 1 Cor 1:26-27


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Reply #4 on: August 27, 2017, 03:56:43 am
The yellow plate is a snug fit. All connections to and from the coil and ignition unit are tight. In the box is a green connector and a random black wire. I think the green connector has been there , not sure of the purpose of the black wire.

I have tried to look for a bullet specific boyer ignition setup video on youtube and on the boyer website but have been unable to find one.  THAT would be helpful.

On kicking I can her one, sometimes two blatty pops in the exhaust, not the usual thump.


mrunderhill1975a

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Reply #5 on: August 28, 2017, 05:36:26 pm
I had an intermittent problem on my 2004 bullet.  After several weeks of checking, changing coil, ignition, etc., Kevin Mahoney suggested I clean the ground wire to the frame behind the battery.  I thought that suggestion silly, but when I removed the battery the connection was corroded with sulfate. I cleaned it off and have not had a problem since.


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Reply #6 on: August 29, 2017, 02:19:37 am
How old is the battery ?
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Reply #7 on: August 29, 2017, 06:44:19 am


Yamahawk

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Reply #8 on: August 29, 2017, 07:20:25 pm
Its about 3 years old. Its a LiFePo4 battery.

https://www.batterystuff.com/batteries/lithium-iron-batteries/sstz7s-fp.html

Sometimes, batteries can show good voltage, yet their amperage is not sufficient. I have found this on AGM batteries, and also Lithium Iron Phosphate batteries also. The battery is the weakest link in a Boyer ignition system, and I would start there, as the Boyer doesn't handle weak batteries very well. Also, lithium batteries don't handle being discharged below about 9v very well, either. Any way you can jump it off of a good battery and try to start it?
Think about the circumstances of your call...Not many were wise by human standards, not many were powerful, not many were born to a privileged position. But God chose what the world thinks foolish to shame the wise, and God chose what the world thinks as weak to shame the strong. 1 Cor 1:26-27


ROVERMAN

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Reply #9 on: August 30, 2017, 08:43:36 pm
This may sound a bit "out there" but i once had my exhaust pushrod jump off the rocker. It ran exactly the way you describe. Only takes a minute to check valve clearances.
Roverman.


tooseevee

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Reply #10 on: August 31, 2017, 01:36:00 am
This may sound a bit "out there" but i once had my exhaust pushrod jump off the rocker. It ran exactly the way you describe. Only takes a minute to check valve clearances.
Roverman.

             I thought dropped valve at the very first because he said loud popping from exhaust and sparks and flames shooting out

              If the pushrod came off the rocker (or the lifter) wouldn't the valve just remain shut?

              Help me out here. I'm not disputing you, I'm just asking. Maybe I'm not thinking it through.
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Reply #11 on: August 31, 2017, 03:20:58 am
My timing is way off. See attached image taken at TDC of the compression stroke. The timing rotor is snug as is the plate. Opening timing side to look at gears. 



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Reply #12 on: September 01, 2017, 05:21:21 pm
Update: The timing gears are all fine. No shearing of teeth. Oil was clean.

The timing is certainly off. That is an easy fix. What has me stumped is why is it off?


longstrokeclassic

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Reply #13 on: September 01, 2017, 06:56:59 pm
Neither end of the distributor shaft has a woodruff key, so it only needs the nut or bolt to work loose and eventually something will slip.


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Reply #14 on: September 01, 2017, 09:37:58 pm
Yes, the shaft is a taper fit with friction.
Loosen the center screw, and turn the shaft back to the location for proper timing.
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