www.YamahaR.co.uk

Hi all Currently R1 4c8, an rdlc 125 in bits all over the house. My hands are usualy covered in oil or muck from landrover. My other intrest. Previous was an R6 5eb loved it, broke it, cracked liner! had CCM, Hornet 600. and thats that.
Thank you in advance. I find myself with an intermitent missfire on the R1 think its all the way through the range but its difficult to notice it at higher rpm. 30k on clock valve clearance checked 7k ago, I changed plugs, checked coil resistance all ok run a little fuel injector cleaner through it no joy It has a power commander fitted k&n filter and akrapovic cans. It gets regular long blasts track action and lots of oil and filter changes. Any advice greatly recived thanks again. Sparky.

Welcome in Mick
I only know the basics , if it's been used then it's probably not old fuel so maybe it's electrics . Have you checked the HT leads ? I had it on a couple of bikes were the HT lead corrodes or the wires break where the plug cap screws on , in your case it'll be the stick coils.
Nice intro by the way , hope you enjoy the forum and get the bike sorted

Hi. Try disconnecting the PC then give it a go


Sent from my iPad using Tapatalk

Welcome mate.

Hi Sparky, welcome and enjoy forum

Hi, welcome to the forum.
Try and get it to misfire at a standstill so that you can check the downpipe temps and locate the problem cylinder. Then swap the coil and injector from the misfiring cylinder, making a note as to which cylinders they have been fitted to. See where the misfire moves to or if it stays with the same cylinder. If a coil has an intermittent fault, it may still read an acceptable resistance when not playing up or under load.
Or maybe possible air leak?

Pete.

I had a misfire on my 4c8 it turned out that water had got into the power commander and fooked it up once disconnected the bike was fine.... but from memory there was a single grey wire That runs from the power commander to the fly by wire throttle, didn't disconnect that and she stopped misfiring but was ran very rough, grey wire disconnected and she was fine .

Good luck and welcome to the forum

Stephen [emoji3]


Sent from my iPhone using Tapatalk

Welcome in mate.
I had an intermittent coil fault in combination with a a faulty set of throttle bodies (bugger to find). Resistance tests were fine until the coil was oven hot then it showed straight away.
Fault was poor stuttering running holding low throttle below 5k. Acceleration and high revs. Smooth as silk.


Sent from my iPhone using Tapatalk Pro

Welcome, also a newbie

Sorry I can't help but where in Lancashire are you?