Triumphrat

webonnielad · 08-25-2007

Even when I’m riding in dry conditions I'm still getting intermittent firing, it starts after about 40 miles when the engine is warm always around about 3200 rpm and disappears at about 4000rpm in 4th & 5th it feels similar to the sensation just prior to switching to reserve.

So far I’ve checked and/or replaced

Spark Plugs
They’re a good colour and the mixture is correct and within safe tolerances for good running. Confirmed by two a successful dyno runs.
In all gears to check A/F, hp and torque prior to the problem I’m now experiencing.

Coil
Coil checked and replaced (the old one checked ok on a meter but I replaced it anyway).
Ignition leads checked and replaced (one of the original leads was found to be faulty when I tested it on a meter).

Carburettor’s = stripped checked and re-checked 5 times.
Floats checked
Jets cleaned
Slide checked
Needle position checked
Diaphragms checked
Carb boot’s checked for air leaks,
Air filter cleaned and re-oiled
Carb blanking points for balancing checked for airleaks
Carb’s balanced
Tank vent in gas cap checked
Breather tubes checked.

I’ve lowered my suspension 20mm all round so to avoid it potentially from hitting my front mudguard so: I remounted my horn under the tank.

The left hand ignition lead runs really close to it. I was wondering if the vibration while I'm moving along could be touching the lead onto and off of the horn.
As there's a HT charge going through it.

The questions I have are:

1. Is it possible for that charge to penetrate the insulation on the ignition lead causing it to short?
2. Could it be the igniter failing to advance properly?
3. A fault with the IPU (ignition pick up)? Gapping perhaps?
4. A fault with the kick stand cut out switch?
5. A fault with the engine cut out switch?
6. Does anyone know how to test a TPS?

If you have any proven test methods for diagnosing any of these I would be extremely grateful for your help.
Just wanted to run this past you before i start getting into solving it in greater depth. The igniters my next best guess especially as it's linked into the immobilizer circuit on my alarm. I just wanted your opinions first.

Jon

Thanks in advance

Geoff · 08-25-2007

interesting.. yes, the high tension charge can leak from a plug wire, usually indicating a fault in the wire itself. One thing we used to do (with a car) was run it at night, if the plug wires are bad, you could see sparks jumping around.
One night it was rainy, and I demonstrated this effect on a friends old beater Pontiac, there were sparks running all around in there like crazy! it looked like disney at nite
G