Hey, I hope someone could help me with the following issue I'm having with a CBF125 2009 model. I've had this bike for many years now and its been very reliable, however the following issue has now happened twice. Today I cold started the bike fine, it fired straight up and continued to idle no problem. I rode the bike 15 miles on a dual carriage way at about 50 MPH, doing some filtering at lower speed (20 MPH etc). At a traffic light (not the first one I came to on the journey) I changed down a gear to stop and the engine cut out. The bike would not restart, it would turn over on the electric start fine, but no ignition. I pushed the bike to the side of the road and gave it 10-15 minutes to cool down, I also walked it back and forth a few time to get air on the engine. After which it fired straight back up again and I rode another 3 miles to the place I park my bike for work (a lot of stop start riding, lots of traffic lights). Exactly the same issue happened last Friday, but on the way home (again after I'd been riding the bike for 15+ miles). Here are some other facts/thoughts. - I recently did a valve clearance check and changed both clearances, the exhaust was very tight and was causing the bike to cut out when cold idling. I did do this check at about 0 degrees so maybe exhaust clearance is too big given the warmer weather. However I did this check about 1 month ago and the issue has only happen in the last few days (I've ridden the bike pretty much every day since the clearance has been changed). - Battery and turn over when the above issue happens sounds exactly the same as it normally does, so it doesn't appear to be a battery/starter motor/electrical problem. - Engine management light goes off as expected when the issue occurs, when trying to restart. So management light isn't showing an issue. - It seems to occur when rapid deceleration happens and gear changes, so going from high revs, to idle (ie when stopping at traffic lights). - Giving some throttle when trying to start the bike, seems to make the bike want to start a bit more, however i wonder if this is just flooding the engine. As mentioned above it seems to be heat related as letting the bike cool a bit seems to help. However heat only seems to be impacting the starting of the engine (and maybe related to the cut out?). Given the mileage involved I'd expect the engine is running at operating temperate for a long time before this occurs. I wonder if its nothing to do with heat, and the walking about with the bike helped some how. Here are things I'm going to try: - I haven't checked/changed the spark plug in a while, and will do this in due course once I get a new plug. Maybe something wrong with the spark plug, as it appears to an ignition issue (maybe explains the cut out?) - I will double check valves again to see what they are at the current temperature. Other than that I'm out of ideas.
