Hi I have a Triton I got as a box of bits. It has a 1962 T110 bottom end and engine number confirms this. It has a T120 barrel and head. Having sent my K2FC mag away to be sorted and still suffering poor starting and running so I have fitted electronic ignition, the Thorspark kit which fits in the mag. Have it fitted to another old bike and really happy with my decision for all those about to hit the keyboard and have a go. I have a couple of questions hopefully those on here more knowledgable than me can answer. My manual on the T110 say 35 degrees BTDC. The T120 is 39 degrees BTDC. Given I have a mix I wondered which way to go. What I have researched would suggest 39 degrees BTDC. I have the auto advance and wondered if I need to set BDTC mark with the auto advance unit locked fully advanced. The electronic ignition says not needed and compensate with the magnets, but this seems a little hit and miss. Thanks.
I haven't done a pre unit electronic kit yet but if you have an auto advance mag i would assume you advance the ring to fully advanced at the BTDC mark as the mag will advance as the revs rise.
You need to set the ign timing at 39 degs BTDC when fully advanced. Best way is to strobe it at high revs. Since it doesn’t have timing marks you will have to make your own. Alternative is to static time it at max advance when the piston is 3/8” BTDC
I would say it depends on the cams you have fitted as they as well as the compression ratio will determine the ideal ignition timing, if you have the T110 cams they will be softer profile and different overlap to the T120 cams.
Hi Hopefully a learned person will be able to put some light on the issue. Excuse long message, but if I give you all the info then it might show what the problem is. I read an article which said with you would use the following formula to time the bike with electronic ignition. You take the degrees of the AAU which is 12 and x this by 2 so giving 24. You then take this away from the 39 degree BTDC so giving you a figure of 15 degrees. This i did and set my timing to this 15 degree mark. Bike fired up great and on the strobe light the light moved to the 39 degree mark when I revved the engine. It did dance around the 15 degrees mark a bit. Built the bike up and took it out and it ran the best it ever has. I could actually stop the engine and confidently kick it over first kick. Ignition system is hidden in the magneto Assumed i had cracked it but several days later bike suddenly started backfiring and running terrible. Just made it home. Timing appeared ok as in not moved. Next day fired it up and noticed one side not running well as it kept backfiring. Other side appeared fine and I could start it easily. The left side exhaust was hot. The right side luke warm. Here is a list of what I have done to try and find out what’s happening. New coil. It is a single coil with two HT leads. New plugs Changed Caps over. No difference Both carbs just had all new parts. Stripped right side carb. All fine Both needles have clip in centre groove No cable issues Checked valve clearances exhaust .004. Inlet .002 so okay. Compression checked and both sides equal and within parameters. Took head off to check valves. All seating correctly and not sticking. Laid spark plugs next to each other and both have same size fat blue spark. Ignition system is using ‘wasted spark system’ so sparks. matched exactly. Anyway not sure what else to check to eliminate. What ever it is must be damn simple as the bike ran a treat and suddenly developed this fault of backfiring and running terrible on the right side and the vast temperature difference indicating the right side was not firing right. Anyone any ideas?
I would say dirt in carb, can you get it running on 2 if you rev it. also have you swapped plugs over side to side.
The carb was stripped so no dirt. New plugs and both firing at same time and swapped over. Tried reving engine and right side backfires very loudly
As my piece says. All new parts for carb and have stripped right carb since problem. All fine. Bowl filling and jets clear. I have an in-line fuel filter.
Have ruled that one out. Floats are brand new and the new type. Both carbs are serviced by one tap into a splitter so no issues there. Fuel delivery from the tickler is quick and same for both carbs.
A flat or low voltage battery can cause the electronic ign to go haywire as you describe. Suggest you check the charging system. Also the magneto drive cog is on a cone without a keyway so maybe it’s slipped? I see you think not but that would give the symptoms you describe. Final suggestion is there might be a duff connection somewhere? Vibes play hell with the connectors. ATB Taff
New gel battery which is on a battery monitor when bike not running. Tested battery charging when bike running and it is fine. Have to say I keep thinking timing and have checked everything is tight. The only thing which I could query is when timing the strope light was slightly advanced or retard of the mark I had. Could not get it it to line up perfectly how much I moved the magnets. However given bike starts first/second kick put it down to age of everything including me Wiring all good and this would be confirmed with big fat blue sparks on the plug.
A vacuum leak on one side ? Try spraying something on each side of the carburettor manifold/intakes WD-40 or similar see if engine running Changes.
Yep thought that one. Renewed o rings and gaskets on inlet flange Nothing changed when I sprayed wd40 before carb strip down. Will try again today just to ensure new gaskets have sealed.
Given whats been reported i would still say its carburetion or air leak as all else has been ruled out, have you checked the flowing enough fuel getting through to the carbs IE partial blockage in tank/tap or lines that's perhaps intermittent, loose jets, as the condition suddenly came on rather than developed, and all else has been checked, but by your description of cool exhaust pipe i would say its a float problem causing over rich mixture.
