Hi All (Apologies in advance for the essay) I am the proud owner of a 2009 Triumph Bonneville EFI SE Mag wheel that I have had for a number of years. I have done the usual mods on this. TORS pipes O2 sensor removal DNA Filter upgrade Relevant TTP map plus various other cosmetic changes. No issues originally but approx. 2 years ago I noticed very very rarely the bike would start snatching and bogging down when accelerating. once I rolled off the throttle it would be back to normal. Recently this has gotten worse and the bike will now daily snatch bog down and then stall if I continue trying to accelerate/ride If I however take the bike out of gear and then accelerate without load the revs go up with no issues as soon as I put in gear again the acceleration sputters bogs down and will stall, if I then switch the ignition off restart everything is back to normal. This tends to happen once or twice during a thirty minute city commute. Also today I noticed that if I pulled the choke out on full both the bike exhausts will backfire at 3,000 revs and the revs will drop down to 2,000 and work back up to 3,000 backfire again and drop down again until the revs drop down lower and lower to I assume the bike stalling (although I did not check to see if that is what would happen as I was sat in traffic.) I recently have done the annual service and have checked for loose wires plugs etc. also checked air filter to make sure it is not clogged up. Bike has not been sat around as it is used 5 days a week for commuting. If anyone has any ideas or similar experiences please let me know, as it is I am at my very limited wits end.
Thanks, I will have a look at the petrol tank breather over the weekend and drop some redex into the tank. Its odd as the acceleration is fine when I take the bike out of gear and then accelerate I would have thought fuel issues would still show unless I am misunderstanding.
Thanks. I have checked the breather tube seems to be connected and no obstruction. on the fuel issue still not sure as per my original comment regarding the rev drop when the choke is on full and bike is not under load.
Is the fuel filter was blocked why does the bike run fine after I turn the ignition off and restart it would a blocked fuel filter not be a consistent issue rather than a periodic one. Sorry not trying to gain say you just trying to get my head round it.
As you have a choke, I presume your bike has carbs. I think it's quite likely a restricted fuel flow issue. Could well be a restricted filter or blocked jet. Turning the bike off and starting it again gives enough time for the float bowls to fill up again. Also check the resistance of the coils when warm. When they break down, first failings show up when warm. Try draining the carbs into a container. Look for crud in there and check the same amount of fuel comes out of each one.
It's not a choke, just a fast idle lever. It doesn't enrich the mixture, it just activates a cam which pushes on the throttle linkage to increase the revs above idle. Same system used on early EFI Moto Guzzis. The injection system wasn't advanced enough to cope with cold starting so needs the "fake choke".
