Misfiring

[Mike H]

During my mini tour to Herefordshire and mid Wales last month the X10 developed a slight misfire, especially noticeable at idle. Otherwise it ran OK. Working on the basis of "what did I do to it last that has changed something", only thing was at last service apart from the oil and filter change was the spark plug. Maybe I've got a duff one?

So today, I was going to put the old one back in to prove it, or not.

No it was much MUCH simpler than that! Plug cap was loose.....  Doh...!


Memo for the future ~ when replacing the plug cap make sure it's fully pushed home ("click"). A squirt of WD40 onto the plug itself first will doubtless help. Then give it a wee gentle pull again, it shouldn't move, if it does, it's still not on properly!

HTH

[spannerman]

Mike, I did the same on my Beverley 350, serviced the bike and it cut out at the bottom of the hill a live on.
I managed to snap the existing spark plug cap (green rubber), only to find out there has been a couple of improvements to the design.
With the upgraded plug cap, it never gave any future trouble.   

[Mike H]

Really? The design looks OK to me, tho yes should be the 'later type'. Main prob is it disappears into the cavity the plug sits in, as does the plug of course, so you can't properly see what's going on in there.

Took it out for a ride today, acceleration is better! 

[spannerman]

From memory (which is fading fast) it was the green rubber waterproof ring that had stuck fast to the cylinder head, and I managed to snap the cap at the 90deg angle. If I managed to snap it off, I came to the conclusion that careless mechanics could be cracking them and causing future 'tracking' problems. The newer types were slimmer and fitted better.
 Still moving on, on my CBF600 getting the middle plug caps on and off is much worse.

[Mike H]

Ta for the info ..