South West Bikers | Motorcycle Forum

My bike was surging the other evening and seemed a little down on power so I took out the plugs yesterday and they looked a bit rough, cleaned them up as a temporary measure and planned to pick some up after work...
This morning I went to start the bike and it backfired and cut off as soon as it fired up, tried restarting and it backfired a load more times then cut... and that was all it would do

So I took the car to work and swung by the shop and got some new plugs, all fitted and it will run now but it has a low idle (less than 1k, possibly 500rpm) and is lumpy but still has the occasional misfire which sometimes causes it to cut out.

Its a 2006 Honda Hornet CB600F

Any ideas what the hell it could be? as nowhere is open to call a professional

you have set the gap correct on your plugs ? clean air filter and no air leaks ? would be the first things I would be checking.

brizzer wrote:you have set the gap correct on your plugs ? clean air filter and no air leaks ? would be the first things I would be checking.

set the gap? I bought brand new plugs, NGK CR9EH-9 which is what Honda list, didn't know anything about "setting up gaps"

PMSL kids of today eh , in the old days you used to have to check the gap between the plug electrodes was the correct distance with feeler gauges, NGK now pre gap them , but i always check em before fitting 25 to 30 thou I usually go with 25 si that it will stay within reaosn as the electrodes erode, it do not attempt to regap iridium plugs though too bloody expensive to stuff up they are

oh right, I'm gonna strip the tank off and have a good look to see if there's any split hoses, rusty earths, loose wires etc to rule that stuff out...

Beyond that, my mate will drop the bike down to the engineers in his van for me... bloody thing

Might be worth checking you haven't either inadvertently knocked your idle down whilst changing plugs, taking tank off etc. or maybe using new plugs as directed in the manual the previous plugs ran on a lower idle. The fact its the hottest day of the year can also affect the running, also it could be some crap in the carbs from when you swapped the plugs and some crap fell down the cylinder. Reset the idle first, take it for a high RPM blast up the A30 then see how it runs? It may be more complicated than that, but it would be a shit to pay an engineer to just reset your idle ;) .

Unfortunately I don't know how to re-set my idle, I did nudge a bar that spans the carbs so perhaps that could be it, it slides back and forth but springs back to place so thought it'd be ok...

Everything seems electronic in terms of set up though as theres no idle screws that I could see...

Its a 2006 F6 Honda Hornet...

Coils??? regulator???

MCH wrote:Unfortunately I don't know how to re-set my idle, I did nudge a bar that spans the carbs so perhaps that could be it, it slides back and forth but springs back to place so thought it'd be ok...

Everything seems electronic in terms of set up though as theres no idle screws that I could see...

Its a 2006 F6 Honda Hornet...

Ahhh is it injection rather than old carbs, I'm buggered then ;)

I'm thinking it must be something I've disturbed as before I looked into it there was only a slight juddering

Going to see if I can find any twisted pipes etc on my day off on Wednesday I think

Make sure the air-box is seated properly & that there are no vacuum take off points exposed or left without covers.

Older 'blades had a habit of backfiring into the intakes, particularly if the throttle had been 'blipped' as the motor was killed. This usually popped off a little rubber cover on the carb balancing stub on the right cylinder inlet tract (the other 3 had screw in plugs) which gave poor running.

Would be inclined to look for something missing, disturbed or not correctly fitted before adjusting tickover etc.

Just took the tank off and side plastics and started having a poke around to see if any hoses were off or anything...


Then I found the main feed from the air induction control valve to the carb had a hole in it... That is definitely not going to help!