banner001 wrote:im gonna go out on a limb and say, too rich on the pilots, hence why when coming to a stop you backfire (too much fuel) and the bike cuts out (overly rich mixture)
I think your right and it is running rich, what puzzles me though is it was fine when I got it and I haven't changed anything apart from the plugs so surely it should run fine still.
I should take the plugs out and check them now I've been riding, might add that to my list for tomorrow, like I mentioned earlier the plugs were loose when I got the bike so I sort of get the impression that was done to lean the bike out by letting in more air through the thread
The plug in the first cylinder comes out black and sooty but the other 3 are just a little bit oily, that was with the bike ticking over in the garage though, like I say haven't checked the plugs since I've been riding.
I'm no professional so I'm not trying to say I'm right and your wrong but from what I've read it tells me it could be an ignition problem, maybe a faulty coil so I've ordered a set of cbr600 stick coils and loom in an attempt to try and fix it.
I have read a lot of your posts and I know you know your stuff so any advice would be greatly appreciated, what's your thoughts on the loose plugs?? Do you think that was an accident or was it done on purpose??
I might try loosen them tomorrow and see what it does
jimsym wrote:Not sure on the differences between models, but my L9 was set up way way way too rich when I got it and sounds somewhat similar to what you're experiencing.
As a result, when starting, it required the throttle a good deal open, and would then require frequent throttle blipping at idle until it had gotten up to temperature.
Also, any choke would insta-stall the bike - I expect this was due to air starvation.
Having said that, I never experienced any backfiring.
Interesting that does sound similar, mine is fine on the choke though but as soon as it gets a little bit of heat in the revs rise for a few seconds then drop off, then rise again then drop until I take the choke off.
Mine will idle fine as well but cuts out if left for a minute, it's when I'm slowing down and going down through the gears the engine stalls and backfires.
The more I think the more it sounds like it's too rich, it's going from revving high with loads of fuel to revving low with loads of leftover fuel flooding it.
You can't just open up the throttle either or it dies straight away, I have to give it a little twist to pick the revs up before I can open it up any more, although I turned the tickover up a bit and it sorted it for now lol
Right so that's it tomorrow the carbs are coming off for a clean up
Just gonna make myself a list of things I need to find out, feel free to add anything
1. Standard jet sizes
2. Air/fuel mixture screw position (how many turns)
3. Air/fuel screw location
Would it pay to just adjust the 1 carb for now as only 1 plug comes out sooty??
Need to go on a hunt for a carb balancer, try get one tomorrow morning
Just a thought the pilot circuit only does the low revs but the problem goes all the way through to the top
The bikes been fitted with an exhaust system so I'm wondering if it's been jetted as well, maybe it's got the wrong jets