Tweet
Pretty happy that my initial problems were simply fixed after my last post about the vacuum advance 'chattering' - see Idle Chattering MkII below somewhere. Thanks to advice (and encouragement) from Brian and Mike Hart.
I now have kicked myself long and hard for being a bit on the 'forgetful' side in putting things back together.
On Sunday morning I had the chance to change the hoses over (‘octopus fuel taps vacuum supply swap with vac advance hose) and one problem was fixed – but I still seem to have a few reluctant cylinders. This time it was a case of running an XS 275 single as only number 4 cylinder really wanted to fire. A few months ago – the last time I had some clear time in the garage to look at the bike - I had a twin 550 – so things aren’t too good and getting worse!
Not a lot of time again, but I took plugs 1 and 2 out, which were wet with fuel and sparking (although No 1 much more readily than 2). The puzzle from before was that the two cylinders not too happy were 1 and 2 – so the old fault diagnostics for a dead coil, where one feeds cylinders 1+4 and the other 3+2 didn’t apply this time. I suppose I should move the plug lead of the working cylinder across to No. 1 and see if that changes anything - maybe isolating whether it's a fuel or electrical problem.
As my time ran out in the garage yesterday I took out the carbs, and - yes, I agree with Mike Hart in his excellent thread on fuel supply changes, air filters and carb set up – what a pain this standard airbox is. I will play with all of that at a later date when I can get the damn thing running reasonably OK to begin with.
Any thoughts from folks who have had a similar problem to chase would be appreciated. One apprehension I have is that someone once told me that this sort of thing can happen when the electronic ignition ‘black box’ is on it’s way out. I really hope it’s not something like that!
I’ll post up any discoveries after I get the chance to look at the carbs.
I now have kicked myself long and hard for being a bit on the 'forgetful' side in putting things back together.
On Sunday morning I had the chance to change the hoses over (‘octopus fuel taps vacuum supply swap with vac advance hose) and one problem was fixed – but I still seem to have a few reluctant cylinders. This time it was a case of running an XS 275 single as only number 4 cylinder really wanted to fire. A few months ago – the last time I had some clear time in the garage to look at the bike - I had a twin 550 – so things aren’t too good and getting worse!
Not a lot of time again, but I took plugs 1 and 2 out, which were wet with fuel and sparking (although No 1 much more readily than 2). The puzzle from before was that the two cylinders not too happy were 1 and 2 – so the old fault diagnostics for a dead coil, where one feeds cylinders 1+4 and the other 3+2 didn’t apply this time. I suppose I should move the plug lead of the working cylinder across to No. 1 and see if that changes anything - maybe isolating whether it's a fuel or electrical problem.
As my time ran out in the garage yesterday I took out the carbs, and - yes, I agree with Mike Hart in his excellent thread on fuel supply changes, air filters and carb set up – what a pain this standard airbox is. I will play with all of that at a later date when I can get the damn thing running reasonably OK to begin with.
Any thoughts from folks who have had a similar problem to chase would be appreciated. One apprehension I have is that someone once told me that this sort of thing can happen when the electronic ignition ‘black box’ is on it’s way out. I really hope it’s not something like that!
I’ll post up any discoveries after I get the chance to look at the carbs.
Comment