Yet another "my XT isn't running very well" thread ...

After much tinkering, I've got my 1984 34L (55,000 km) back on the road and running. It starts perfectly, first kick, hot or cold and appears to run fine ... until you get to about 80-100kph. Then its starts to cough and splutter in an alarming fashion. Not 'backfiring' sort of coughing, just 'momentary total loss of power' coughing.

Having trawled through the various threads here, I strongly suspect that it's the inlet rubbers and have ordered a new set from Kedo (only 44 Euros). I've not replaced these in the 20-odd years I've had the bike, so it probably needs doing anyway.

While I'm waiting for these to arrive, I've got suspicions about the secondary carb - there's a thread about wobbly diaphragms which rings bells from the last time I had the carb to bits (to clean all the passages out thoroughly). Does anyone have any idea what road speed the secondary carb usually kicks in (or not)??

[edit: a friend tells me that the secondary carb comes into play around 1/4 throttle, so its probably not that then - my problems start at around 3/4 throttle. Hope the inlet rubbers fix it - any other ideas very welcome in the meantime ]


I should that say I've checked all the various float height, secondary carb sync etc.

Well, I'm astounded: new inlet rubbers fixed the problem

S'funny, though my logical mind said it had to be, I never really believed it would work. Just goes to show what a fine bunch of folk you all are. Thanks to those posters-of-the-past that showed me the way to enlightenment.

(and thanks to Kedo for such swift despatch)

Frrarrrrrrppp!