Triumphrat

elsdonf · 09-10-2009, 10:21 AM

Hi All

I have a 2001 Truimph Bonneville. It started cutting out when the tank was low on fuel. Reserve made no difference. Filled up with fuel and all was okay until low again.

Drained and cleaned tank, line, drained and cleaned the carbs (without stripping them). Replaced all parts, still no difference.

Bike would run for 20km then fire only on one cylinder and then die. Wait 5 minutes, start again and then run for 2km, drop to one cylinder and then die again.

In the wintertime, when the temps are 20C, it ran better. Now in the summertime, 32C+, its very much worse.

Cleaned all electrical connections. Replaced spark plugs, HT leads, HT coil, pickup coil. Now it will run with the choke out but cuts out when the choke is closed.

Now stuck for what to try next. Help greatly appreciated.

One frustated, house bound biker.

BombFactory · 09-12-2009, 11:50 AM

Could you clarify one thing please: you say it runs with the choke "out" but stops when the choke is "closed"; are you referring to the position of the choke control or the actual choke barrel/plate? I assume you are referring to the choke control (i.e. the choke being "out" means the choke barrel/plate is closed and in use, and the choke control being "closed" or pushed in means the choke barrel/plate is open and the choke is not in use). Is this correct?

It sounds to me like a fuel starvation issue—especially if the engine runs when the choke is applied and the mixture is extra-rich. This may also explain why it is running on one cylinder, as, correct me if I'm wrong, but each cylinder is directly fed by one carb. It would seem to me that some debris is in the carb of the dead cylinder, or something else has coincidentally gone awry in that carb.

Are you getting spark to both cylinders, even when running on one?

mglemans86 · 09-17-2009, 10:53 PM

Remove the fuel petcocks. You may find the lower portion of the filter screen is clogged.