engine caught a cold??

[oyster]

Just lately the engine seems to 'sneeze' occasionally! It's reasonably well tuned, new plugs, various fuel supply. On, usually, low throttle either after roll off or gentle riding in traffic, it seems to do a violent, single sneeze. Appears to be on the right side. I wonder if its blowing back through the inlet? Performance seems to be as good as usual on acceleration. Anyone else enjoyed this experience? And, how is it cured?

[gus]

Hi
Well you say the bikes reasonably tuned.It need to be in good tune.
Check valve clearances,sync throttle bodies clean plugs etc etc.Make sure the little black nipples which cover the vacuum take offs are not perished and leaking.
Mr sheene,s bike did the same until i adjusted the valves correctly.
good luck
gus
ps check for leaks on exhaust system aswell

[oyster]

Thanks Gus, I have done all as suggested. No exhaust leaks. I am wondering about a tired injector?
anyone?

[Stevie]

It sounds like something my bike used to do when it was very new (<6000 miles) but has only happened, I think, twice since. The last time was about 1000 miles back and it's due it's 18000 service now. If you ever find out please let us know. The dealer (John Clark, Dundee) never found the source and it happened so infrequently that I never bothered chasing it.

[Boxadog 2000]

Check the wires that go into the ignition switch, my bike had exactly the same problem and it turned out to be a broken wire.

[gus]

How many miles has the bike done?
Were the valves set correctly using four feeler gauges?
Mr sheenes bike had exactly the same symptoms.A little fluffy sounding with the odd sputter and back fire.It had new plugs,airfilter etc etc and had just been twinmaxed.I checked the valves using the four feeler method and adjusted accordinally.
This cured the problem.
I aint sayin yours is the same problem.But it wont hurt to double check.
gus

[oyster]

18 000 miles old. Four feeler valve adjust.
Bob, I checked my ignition switch after you posted the pics a while back, and checked all the other known wire rub places. Left fuse box v. faring is where my wire bundle was getting friction!
I believe it may be dodgy injector. Today I did fifty miles with a rich mix of injector cleaner, and another fifty on normal fuel. It seemed to help.
Any further advice out there? I want another four months of good riding before the winter lay up and my latest collection of goodies are added!

cheers!

[gus]

Well if thats the case then i recommend riding it on the limiter everywhere.That should sort the lump out good and proper.
Hope you get it sorted.
gus