hey chaps. Took the bike out last Saturday and at high revs it was bogging pretty bad, I have read another thread on here but I didn't see a cure from the op. So I'm thinking fuel or current issues, sounded like it was still firing just suddenly a few thousand rpm lower then it would kick back in again, I think that sounds more like fuel, Maybe filter? Pump relay? I'm a bit short of time at the mo so wondered which direction to go in first? Idles and starts fine, happened about 10 times during 2-3 hours riding, full tank, good batt, no fault codes. Any help gratefully received
Could also be the front coil and even the ecu as with my 999. Condensation over winter can produce water in the tank as well. That might be a good place to start...
Thanks fellas, I can spend a couple of hours on it tonight so will check filters, coils and will clean as many connections as poss. Got a small window to test it tomoz morning so will update thread with any progress Thanks again
Possible faulty petrol tank vent. When was fuel filter last changed? I would change the fuel pump/injector relay to eliminate that. What's the mileage on the bike? I experienced similar symptoms to yours, turned out to be valve clearances!
Could be fuel tank vent, I had the tank off recently to do belts and it was a pain getting the tubes back on because of a silly carbon cover. Will check that first. Bikes done Just over 10k, valves were done at 5k according to prev owner. No idea when/if the fuel filter has been changed...is there a mileage recommendation? Thanks for replying
It was a few years ago now so struggling to remember the mileage, somewhere in the region of 10k. Once the valve clearances were done the misfiring/bogging down issue disappeared. I vaugely recall the mechanic at Snells mentioning that valve seat recession could be an issue as the valves have a hard time.
Likely if you have changed/done something on the bike, and then the issue appears very soon after, its related to what you did. Blocked/kinked fuel pipe, breather, something like that would be my £1 each way bet Could also be if you drained the tank there is crap in the filter that needs clearing
So this wasn’t a normal service, where several things were done to the bike, such as changing the fuel filter, plugs etc. ? The only work carried out was correcting out of tolerance valve clearances, nothing else?
most likely bradders... I'm slow taking things off but have a habit of putting it back together too quickly. I'll learn one day... Last night I Checked vent pipe, cleaned earth connection, changed horizontal plug, checked air filters and cleaned a few connectors. Will lift the tank this morning and check the hoses then give her a run, see what happens. Am gonna order a new fuel filter Etc so I can change that ASAP. If it was valves wouldn't it generally run lumpy? And start consuming oil? Thanks for your help fellas
Managed to do a bit of a test this morning and it seems to have gone, will change the vert plug now to match. Will still do the fuel filter though as i doubt its ever been done. But... I did notice a switch hangin off the under side of my clutch lever? Looks like a brake light switch. Any one know what its for? Doesnt look like its been on for a while as the old glue is now dirty. Looks like it had been pushed up into the switch wiring to keep it out the way. My other bike has a standard clutch lever and has this switch, i just dont know what it might do? Thanks again for your input
The clutch switch overrides the side stand/in gear starter safety circuit to allow you to start the engine in gear when the stand is up (and clutch pulled in)
Got out for a proper ride sunday, got about an hour in and its bogging again, as low as 7k now... Next step gonna do fuel filter this week and pinch coils off my tb. Fingers crossed
Possibly heat related Blakey, if it happened an hour into your ride. Can you do/get a cylinder compression test ? iirc you should be looking in the region of 150psi in both cylinders.
No idea of it could the the same, but I had an old 600 monster that had the ignition pick ups fail at temp. So perfectly fine until 2 laps in the itvws slime it was running out of fuel.
