Triumphrat

My05Thrux · 11-04-2012, 04:16 PM

Had the same issue on a 95 TBird - went thru the carbs, gas flow, coils, before discovering that the sensor on the end of the crankshaft that senses the three bumps on the crank, acting like a distributor and telling the coils to fire was wearing out. Only failed at higher revs, but eventually got worse and I did enough reseach to figure it out. It was a simple fix once I figured out what the issue was.

Aunatural · 11-04-2012, 07:54 PM

That is the part that I suspect. When it happens it is misfiring on all cylinders and the tach gets "bouncy".

IrlMike · 11-05-2012, 04:39 AM

I missed that earlier. Thought for some reason you had already replaced it? Definitely an item that could be causing the fault. Check the gap before buying a new item (tho' it's a good spare to have) - it's critical, as the sensor output amplitude varies with rpm & unversely with the gap, which isn't a desireable characteristic as all the igniter wants is the zero crossing point as a rotor lobe passes it. 0.6 to 0.8mm is the spec. I prefer to be toward the 0.6 end. A new engine cover gasket will be needed, but the oil level is well below.

If the gap is ok, it would be worth checking the wires to it for any intermittant continuity issues. Unplug the igniter & connect a resistance meter firmly at each end, wiggle/bend the wire & look for any jumps in continuity.

lovecuba · 11-05-2012, 03:21 PM

In my view are absolutely necessary on our machines. The crude factory filters are actually 'strainers' hence the need for two of them!
Fuel should be filtered up to the standard of injected motors where even the tiniest amount of grunge can ruin an injector, whats so wrong about applying that standard to our fuel delivery systems?
A good quality inline filter will have absolutely no effect on flow, if it does, then it is doing it's job.

denny · 11-05-2012, 05:54 PM

One thing I've considered....

Filters that are made for fuel injection might be made to operate at higher pressure.

i.e. Fuel injected bikes have fuel pumps and their fuel system operates at a high pressure when compared to the gravity feed of our bikes.

So I chose an inline filter that originally was used on an 1100cc Carbureted Honda.

So far so good, since 2003 with no problems. I've had the carbs open a few times and no dirt in there either.

lovecuba · 11-05-2012, 06:05 PM

Quote:

Originally Posted by denny

One thing I've considered....

Filters that are made for fuel injection might be made to operate at higher pressure.

i.e. Fuel injected bikes have fuel pumps and their fuel system operates at a high pressure when compared to the gravity feed of our bikes.

So I chose an inline filter that originally was used on an 1100cc Carbureted Honda.

So far so good, since 2003 with no problems. I've had the carbs open a few times and no dirt in there either.

Yes, you are right on Denny. Take the fuel injected 955 for example. It as a pre pressure filter that sits in the tank on the inlet side to the pump, on the pressure side is a canister filter between the pump and injecters. This filter is packed with a DIN standard filtering media which is far superior than a gauze strainer. There are small inline filters available that have this superior media fitted and work well without having to be fed by pressurised fuel.
Whilst the clearances and pressures involved in fuel injection systems are not applicable to our machines having absolutely clean fuel delivered to the engine is.

WSC · 11-06-2012, 11:07 AM

I'm sure you can find a filter that will work, but indiscriminate installation of any old filter can definitely cause trouble. Keep in mind, with a gravity flow system you have somewhere in the neighborhood of 0.2-0.3 psi to work with. Any pressure drop across the filter can be problematic. I've seen many cases where the filter caused the bike to "run out of gas" despite the fact that the tank was above the reserve level. (Switching to reserve had no effect.)

Any containment smaller than the smallest orifice in the carb should pass through harmlessly. Filtration beyond that level is pretty much pointless. Fuel injection systems with injector seals and higher pressures are a completely different animal, subject to erosion in addition to simple blockages.

Aunatural · 11-08-2012, 12:50 PM

Well, it's alive and kicking. Replaced the ignition pick up and off we went. For fun I did some voltage drop tests after the bike was warm and found a half of a volt drop on the coil feeds when warm. Cleaned that one up too. Runs and pulls fine. Just for reference, it does have an inline filter, Mikuni's, pods, and an ignitech unit. now if I could just come up with a set of cams and a 3-1 header.......