Tri-spark back fire on start carb, caught fire....

Tri-spark and custom rewire /new 3 phase alternator on 850 commando.. So far I did the normal setup for the trispark tried to do a one man strobe turned out to be impossible for me, anyways it kicked back at me which was surprising but much less than I was used too but I took for a ride and after a short break kicked to restart flames shot out of carbs and right carb caught fire I jumped into action and put it out immediately.. Scared the shit out of me, the idea of this beast burning up..... anyways it started next kick fine but it does slightly back fire sometimes as I let off the throttle any Ideas... Thanks

Oh my Jeremy, back fires to point of starting fires implies a wee bit too advanced, so tweak some retard till she just don't backfire, then follow your favorite method to actually try to measure what that is in degree's. For some reason after I've had some of these events the spark plugs sometimes failed from fouling cooked in I guess. Just keep in mind after fixing or fine tuning one thing, another may have crept up to annoy ya.

Backfiring is what a Boyer does when your battery is failing. The Trispark retards further and I've never had a backfire yet.
I suggest you double check everything:

1. Are the timing marks on the chaincase consistent with reality? - It's only a couple of minutes with a plug out to check actual TDC, and different alternator rotors can be quite a way off.
2. Double check the Trispark has been set up per the instructions - its very easy... mine strobed up to within a degree or two on installation, and ran absolutely fine.

Evidence here - this was the first kick after rebuild - the ignition only got strobe checked after the first shake-down rides.

[video]http://www.youtube.com/watch?v=OQGQ8uK-pYM[/video]

spanskAlpha
I replaced my Boyer with Tri-spark on my MK3 last year. Have not had a kick-back since. Has worked with the engine in winter, and will set back my Tri-spark.
Was then a little unsure what to put it on.
Is it 32 degrees at 3000 rpm?

Vidar

vidar hjelm johansen said:

Is it 32 degrees at 3000 rpm?

Click to expand...

28 degrees for Tri-Spark.

3000 rpm, ?
Vidar

vidar hjelm johansen said:

3000 rpm, ?

Click to expand...

Just increase the RPM until you reach the point where the strobe shows the ignition has stopped advancing, that should be somewhere around 3,000 RPM.

Jeremy, how did you put out the fire?

Dave
69S

The carb that caught fire was lucky on the right side, the side i was on... I just immediately hit the petcock and shoved my face right up to the carb (since I been messing with the bike I have not put the air filter back on the bike which probably didn't help) but I just gave it one strong short blow of air right in the carb and it just went out, over all was probably only 4 sec... But that gets the heart going.... I basically restarted the tri spark install this time using the 28 degree mark on the primary instead of the one I tried to make... It seems to be much closer.... The only problem i have with the Tri spark install is I think there should be two marks on the stator to line up the B mark to later line up the rotor marks using a straight edge to line the rotor marks off of one B mark seems to leave too much area for guestimating the actual line??? If that makes sense am I the only one who can overthink easy install instructions???

Lucky boy. I had a Farmall Cub catch fire on me one day, long time ago, I think from the ignition wires, forget how it happened, but I do remember it settled down to a small flame coming out of the tank (the cap was off). I really didn't know what to do, but I had the cap in my hand and I just put it over the flame and it went out. I suppose it could have exploded all over me, now that I think about it, but it didn't. Not sure what I'd do today, probably run, or maybe the same thing still being just as stupid.

I guess that's why I asked. Thanks.

No more fires please. Let's keep those taps and floats working right, not leaking.

Dave
69S

Ugh, you should always fight a motorcycle fire as they don't blow up just melt away and can take out other things if just abandoned. Push or throw bike out of any gas spill below it and let if fall side ways so flames not hitting tank then huff and puff from below upward and hope it goes out before you do. If not sprung a real big leak should go out till just the gas tank cap or it over flow burning, then move bike again and try covering the tank with jacket or pants or what ever.

I saved P!! blowing out the flames at gas station on cement, so know to start at bottom and work up now, not the other way around of just re-lights from below.