My 2005 Thruxton has developed a miss it only does it once in awhile and it's hard to figure out. We have moved from sea level to around 7,500 ft. elevation and I have rejetted and the plugs look a nice tan color on 91 non ethanol fuel. It seems like it just cuts out for a stroke and then goes back to a nice idle. I have changed the plugs and checked the wires going to coil and spark plug wires and all seems good there. I have also purchased a Twinmax electronic carb balancer and adjusted the carbs. The bike runs great at speed and am really happy with the way it runs, it's just this little miss at idle that's driving me crazy. Could this be a clogged air, pilot or something else?? Thanks in advance for your help. Chuck.
My old T100 of the same vintage did this before stuttering more seriously when hot at about 3,000 rpm. It was the ignition coil (not the pick up which can mimic the same problem). I replaced it with a PVL (sold as Nology in the States) problem solved. You can check resistance values in the windings but until they fail totally with an open circuit can give a good reading. The fine wire breaks but makes intermittent contact. On an OEM Gill coil you should get something in the region of 15-17 ohms between HT sockets, nearer 25k ohms measured via the plug caps.
I'll check that today, it does seem like the ignition cuts out just for a split second, I'm suppose to be going on a gathering with some friends Thursday that will end up being about 700 or so miles, damn. But it runs so good at speed. Thanks for the reply, Chuck.
Today I pulled the carbs completely apart and cleaned everything and blew air through all the passages. All looked good so put them back together. Now I have a steady idle, all I can figure it must have been clogged somewhere? I just hope that was it and I don't get stuck going through the desert, it's suppose to get hot on our way. Wish me luck!
If it was dirt in the carbs then try adding some fuel system cleaner to your fuel for the next few fill-ups. Modern petrol is pretty crappy and will leave gum/varnish/shite wherever it can. Can't do any harm to try. I've used Redex in my '95 Trident 900 for many years with no problems - other fuel system cleaners are available (Lucas in the USA?)!
Tearing the carbs apart and cleaning all the passage ways out did the trick, I went on a ride over the Million Dollar Highway (550) North to Montrose for a bike meet. This highway goes over three passes that are 10,610' 10,916 and 11,004' and the bike ran great!!!!! This part is from Silverton going toward Red Mountain Pass at 11,004'. Thanks for all your help guys and here is a video of when I got clear of traffic and was able let her stretch her legs a little. Thanks again, Chuck Horton. www.youtube.com/watch?v=BJByskZ6NeE&t=13
