Yamaha TRX850 Enthusiasts Forum

Hi guys

I put a top yoke and riser bar kit on my TRX this week and everything went ok (apart from those dastardly shear bolts). After I bled the brake lines I fired it up, keen to take it for a spin, but itls only running on 1! - the left one

Now I assumed it was electrical - maybe I dislodged something with the bar swap - since there wasn’t even a cough from the right cylinder. However after pulling the leads out and testing with a spare spark plug there was a strong spark on both

Next thought - maybe no fuel getting to corresponding carb. I took off the air box and started it and sprayed a bit of WD40 into the inlet – I reckon if it wasn’t getting fuel it would have at least farted when I did that, right?

Now I’m wondering if anyone knows something that could make my bike go from running perfect to running strictly on 1, without so much as a cough of warning?

Thoughts include
– the spark plug in that cylinder has failed somehow (the first thing I will check tomorrow)
- a passageway in that carb has suddenly become all blocked up (carb strip down and clean will be my second task)
- something mechanical eg. valve stuck open
- other

Cheers,
N8
SR500
XS650
XR350
TRX 425

As it was running absolutely fine before you fuk't it up I'd suggest it is most likley electrical. Try flickinhg the kill switch on and off a few times. And If you are getting a spark to both plugs, check the actual plugs. Then check all of the connections for the electrical system righht back to the plugs

Also, try something like carb cleaner (or 'Start Yer Bastard') to spray into the carbs rather than WD

turns out it was the spark plug

Back on the road and running better than ever, thanks

cheers, n8

Unbelievable coincidence this!! Must have been something weird in Perth last week - mine was running perfectly last time I rode it - put in the shed for a few days & next time I went to start it the RHS plug had nothing! Fitted new plugs & she fired up straightaway - very spooky!!