Triumphrat

Wombat

I spotted a 2000 Thunderbird on Craigslist and shot off a few questions to the owner who replied with this:

The bike has been sitting for a while, however, the problem existed prior to that period. It manifests itself as a drop of about 1000 RPMs both at idle and while it is running. It is getting beyond my capability to diagnose and know that someone else would be able to do a lot with it and enjoy it like I have. It is running, however, today I had an instance which was the last straw for me. I increased the idle RPM to try to mitigate the issue and was riding it today when it shut off in traffic. After it cooled down it returned to it's previous condition. I took the carbs off the bike last month to clean them out in case it was a blockage problem, but that was not the case.

He is asking a high price for a bike in good running order but I would like to hit him with a reasonable price for the condition it is in.

Any thoughts on what may cause this issue?

My first thoughts would be Ignition pickup and/or coils.
My next guess would be the ignitor.

There is not much else in the system, is there anything else that I would need to consider?

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Bob

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Age is of no importance, unless you are a cheese.

Tbirdnz

My guess would be the coils breaking down when heating up, maybe #1 coil


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Ride on !

Wombat

I am thinking on the same lines

Doesn't #1 coil drive the tach?

__________________
Bob

Click to see My Photo Album

Age is of no importance, unless you are a cheese.

IrlMike

Doesn't sound quite like the usual coil fault to me, or what I've read of the pick up failing.

But does sound electrical/ignition. I've just had to pinch up the coil connections - they had definitely loosened over 5k miles or so. What led me in that direction was a delay in the tacho beginning to move when starting - a few seconds before getting off zero - not normal. After going over the connectors it has not happened again. (I think there was another thread recently with the same issue.)

(It is No. 1 coil o/p feeds the tacho I think, Brown/Yellow wire is on rearmost coil IIRC.)

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Legend chassis, Tbird tank/seat, Sprint fairing, tubeless wheels, Thunderbike 3-1, air box mods, 115/40 jets, DJ needles, Ignitech with TPS, ZX6R shock, ZX7R USD forks/yokes, Alcon 6 pot