Swapped Boyer for Tri-Spark

[swooshdave]

I know the bike had a Boyer when I got it back in about 1993. I don't know if it had been replaced at any point since then. The bike starts with one good kick when it's warm. Not much to complain about there. Idle was ok. But for some reason I just have a hard time when it's cold. My brother seems to be able to start it when it's cold but I just have never figured it out.

After seeing @Mike T bikes start right up with their Tri-Sparks and I had a couple hundred in my piggy bank I reached out to @marshg246 and a Tri-Spark showed up in just a couple days. It sat around for a while but I had some free time today and invited @Mike T over to supervise.

I had switched the bike to negative earth a few years ago. After taking some pics of the existing wiring I just ripped everything out. I whipped up a wiring harness and plugged everything in. And nothing. No light. Make to the instructions. Yeah, I had been looking at the wiring diagram for the positive earth for the wires at the timing area. Not sure why. I'll blame the heat.

Sorted out the wiring and got the tank back on. Gave it the lightest kick and it fired right up. And just a lovely idle. Warmed it up a minute and put a timing light on it. At 3500rpm it was about 35 degrees. Adjust the unit and timing was spot on.



I'm looking forward to how it starts in the cold.

And the Boyer when in the bin.

Also that INOA shirt is at least 35 years old.

 

[CanukNortonNut]

Swoosh,
Are you running a choke with Amal's or blanked them off? I find that I have got to put on the Choke or Air Valves on a cold engine with my Pazon Sure Fire. Similar to the Boyer.4

 

[swooshdave]

Single Mikuni on this one.

 

[Onder]

Ironic. Last few days wrestling with two no-start bikes. RE Interceptor absolutely refused to go. Pazon SureFire. Pulled it off and put on a Pazon Altair I had. No start but constant kickbacks. Took that off and put on a new SureFire . Same deal less the kickbacks. Tried to start the Commando with an Altair. No start constant kickbacks.
After hours of this both suddenly will start and run fine. And just to note that EVERYTHING has been checked and rechecked fuel,air, electrics etc.
Total mystery. And yes I have the same Boyer EI in your pix on the shelf. It may go on next!

 

[Fast Eddie]

I know the bike had a Boyer when I got it back in about 1993. I don't know if it had been replaced at any point since then. The bike starts with one good kick when it's warm. Not much to complain about there. Idle was ok. But for some reason I just have a hard time when it's cold. My brother seems to be able to start it when it's cold but I just have never figured it out.

After seeing @Mike T bikes start right up with their Tri-Sparks and I had a couple hundred in my piggy bank I reached out to @marshg246 and a Tri-Spark showed up in just a couple days. It sat around for a while but I had some free time today and invited @Mike T over to supervise.

I had switched the bike to negative earth a few years ago. After taking some pics of the existing wiring I just ripped everything out. I whipped up a wiring harness and plugged everything in. And nothing. No light. Make to the instructions. Yeah, I had been looking at the wiring diagram for the positive earth for the wires at the timing area. Not sure why. I'll blame the heat.

Sorted out the wiring and got the tank back on. Gave it the lightest kick and it fired right up. And just a lovely idle. Warmed it up a minute and put a timing light on it. At 3500rpm it was about 35 degrees. Adjust the unit and timing was spot on.



I'm looking forward to how it starts in the cold.

And the Boyer when in the bin.

Also that INOA shirt is at least 35 years old.

Best invest you’ve made in the old girl IMO!

Don’t bin that old stuff Dave… some schmuck will buy it !!

 

[Matchless]

I put a Boyer MK3 on my 850 when I first built it twenty odd years ago. It failed two miles into the first ride. Boyer sent a replacement FOC. That worked fine but I could never get the bike to idle reliably, sometimes it would & other times it would stall, & always thought it was a carb issue. I tried rebuilt Concentrics, brand new Concentrics, a single MK2, & an SU. Then someone on here said he had cured the same issue by fitting a Trispark. I fitted one that same week & it completely cured the problem.
It would seem that Boyers are inconsistent in their manufacturing as most are fine as far as I can tell.

 

[o0norton0o]

The "thing" about this kind of thread is that there are always other variables present when we make our conclusions and those variable differ from bike to bike. The last time someone started extolling the virtues of tri-spark, I sent boyer an email about their spark timing for their Microdigital (red box unit) They sent me back an answer saying that below 400 rpms the red box spark timing is +40 degrees from full advance, so that would make it +9 if the full advance is set to 31 degrees... You would think that at +9 that even a very lean mixture could never kick back because the spark should be well past TDC, but it does... I have a procedure that I've developed over time to start my bike to avoid kick back but the threat is always there.

In fact, I can make my bike kick back every single time if I wanted it to do that, but you would think with +9 timing that would be impossible.... I would love to hear speculation why it still will do that.. My own theory is that the magnetic triggering is very inaccurate at low rpm's. Any other ideas?

Does a Tri-spark NEVER kick back?

 

[hhh]

The "thing" about this kind of thread is that there are always other variables present when we make our conclusions and those variable differ from bike to bike. The last time someone started extolling the virtues of tri-spark, I sent boyer an email about their spark timing for their Microdigital (red box unit) They sent me back an answer saying that below 400 rpms the red box spark timing is +40 degrees from full advance, so that would make it +9 if the full advance is set to 31 degrees... You would think that at +9 that even a very lean mixture could never kick back because the spark should be well past TDC, but it does... I have a procedure that I've developed over time to start my bike to avoid kick back but the threat is always there.

In fact, I can make my bike kick back every single time if I wanted it to do that, but you would think with +9 timing that would be impossible.... I would love to hear speculation why it still will do that.. My own theory is that the magnetic triggering is very inaccurate at low rpm's. Any other ideas?

Does a Tri-spark NEVER kick back?

If it's kicking back at theoretical ATDC, I would assume it's malfunctioning and not getting the first cycle correctly timed. What conditions guarantee a kick back? I get occasional kickback on my TR44W with a red box Boyer with full advance timing set to about 28.

 

[Fast Eddie]

Does a Tri-spark NEVER kick back?

Good question !

I’ve been fitting Tri Spark to Triumph and Norton twins and triples for years, and many bikes.

I cannot say with certainty that NO Tri Spark has ever kicked back, but to the best of my recollection, I do not believe I have ever suffered one.

I know that not everyone enjoys success with Tri Spark, but I think I’m on something like my tenth, and have NEVER had one fail.

 

[o0norton0o]

If it's kicking back at theoretical ATDC, I would assume it's malfunctioning and not getting the first cycle correctly timed. What conditions guarantee a kick back? I get occasional kickback on my TR44W with a red box Boyer with full advance timing set to about 28.

A lean mixture kick guarantees a kick back on my bike. If I don't bleed the bowls enough or open the throttle too soon, I can make it kick back every time. So,... now I bleed the bowls, then give a light kick with the ignition off. Then I turn the ignition on and give it a good kick and raise the throttle as it lights off. I have the choke bodies removed on my amals and I'm sure it would help to have them kick back less often.

I'm really interested in hearing if the Tri-spark NEVER kicks back...

 

[Tornado]

Well, my little old Wassel-Vape EI...been on the bike now 8 yrs, 25k miles....only kicked back once when I diddled with a scosh more advance....put it right back to where it was happiest (28-29 BTDC) and never again kicked back...starts mostly 1st/2nd kicks hot or cold...nearly never more than 4 or 5 kicks. I put that down to kick technique/engine rotation point before the big push. Dual Amal Premiers, no chokes.

 

[seattle##gs]

I have a routine with my Tri-spark. Put the kickstart in the 10: o'clock position and get ready to kick. Then turn the key on and kick through. Otherwise it kicks back often. The Trispark is a very good ignition and my favorite of the three. But give Boyer some credit...it's been firing your bike since 1993. That's 32 years.

 

[Cuppy]

Good question !

I’ve been fitting Tri Spark to Triumph and Norton twins and triples for years, and many bikes.

I cannot say with certainty that NO Tri Spark has ever kicked back, but to the best of my recollection, I do not believe I have ever suffered one.

I know that not everyone enjoys success with Tri Spark, but I think I’m on something like my tenth, and have NEVER had one fail.

My TriSpark kicks back and has put me out of commision with a severely sprained ankle already once this year. It strobes at 29 BTDC. I have to be very careful not to give a lazy kick when starting.

 

[Fast Eddie]

My TriSpark kicks back and has put me out of commision with a severely sprained ankle already once this year. It strobes at 29 BTDC. I have to be very careful not to give a lazy kick when starting.

Well that certainly answers the question about them never kicking back !

You do now that you have to hold it above 4,000 to strobe it properly ?

How does it time with the LED ?

I don’t strobe mine anymore. I found that setting it with the LED made it strobe cock on, so now I just set with the LED.

 

[Cuppy]

You do now that you have to hold it above 4,000 to strobe it properly ?
Yes
How does it time with the LED ?
Dead nuts on 29

 

[Tornado]

You do now that you have to hold it above 4,000 to strobe it properly ?
Yes
How does it time with the LED ?
Dead nuts on 29

What vintage of TriSpark? They do get updated with better features....perhaps yours is pre-anti-kickback?

 

[Cuppy]

What vintage of TriSpark? They do get updated with better features....perhaps yours is pre-anti-kickback?

It was one of the 1st TRI-0006 models. Got it from Greg Marsh. According to Greg it shouldn't be kicking back.

 

[Matchless]

I have a Trispark on the 920 Commando, the TR7 750, & also one on the T150 750. The first two are the points housing type, the latter is the sequential firing separate box type. I can honestly say I have never suffered a kick back with any of them. I think kick back is often down to issues other than ignition.
Whilst I am no lover of Boyer ignition systems, having had problems with poor tickover & failure on a Norton, pinking on a BSA A65, & cutting out on the TR7 (red box type) I know that many people love them. But for me the Trispark seems to work like the Lucas points set up, which if in good condition works perfectly. Just not when worn out, rather like Amal carbs.

 

[Cuppy]

But for me the Trispark seems to work like the Lucas points set up, which if in good condition works perfectly. Just not when worn out, rather like Amal carbs.
Mine is was new 2 years ago and has 400 miles on it. It has occasionally kicked back only a few times and works a treat otherwise.

 

[ashman]

I ran my old Boyar for over 32 years and was still going when I went down the Joe Hunt way, in all those years my Boyar only kicked back 2 times, had a belly of fuel and a lazy kick, it also idled good when at traffic lights.
Was also a everyday rider when running with the Boyar so average 6k to 12k miles yearly, rode it everywhere.