Bike gone funny

Nev said:

You Should put spark plugs into the leads and place them on the engine, to earth them when turning the engine over to avoid problems....... There will be faults in the ecm. Clear fault codes, check you have not torn the plug caps/rubber ends etc when removing the leads from plug tops. When there is a misfire the O2 reads lean, so your autotune will chuck in a heap of fuel, which it then later trys to pull out. I think it very unlikely you have damaged the ecu. They have a number of failsafes built into them. Why are you running an auto-tune? Is there no-one to tune your bike where you live?

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Hi Nev i understood that but got lazy as there were 6 plugs, so regretaably just unplugged coils instead..
do you think it would be a good idea to clamp a digital tacho on the plug leads individually and monitor which ones are firing/misfiring?


There were fault codes which i cleared, an ignition circuit fault for cylinders 2 & 3 (i had the coils disconnected on them, but only pulled the leads off the plugs for cyl #1) and a fuel pump error (i removed the pump relay). clearing the codes didnt make a difference in this case.
Also the misfires which kill the motor happen only when around idle... open up the throttle and all is well. I must check throttle position calibration on the PC5.

There is a guy who can do dynojet tuning but I like to have a live AFR on the whole time - for example the PC5 went dodgy back in January and ran very lean (discoloured the exhaust flange bolts), i only spotted it due tot he AFR gauge. Updating the firmware on the PC5 fixed it.

if a bike is firing on only 2 cylinders, does it cut out or just run weak?

idk said:

I ran mine on two cylinder for about 5 miles in Canada (sorry, 8 kilometers. )when a spark plug popped out. I disconnected the coil and injector for that cylinder and rode into a town where a mechanic loaned me the tools and I fixed it. It felt like I was riding a Harley.

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ok good to know, i was wondering if i had a dead coil or somehting. it still goes like a scalded cat, just rough around idle and ignition will intermittently die for a sec when revs are anywhere from idle to 2000rpm or so
i wire brushed, greased and recrimped the coil connections and it made no difference. wondering what to try next