Strange Knock.

[seb421]

Dont really know how to explain this other than it does it once in a while

bassicaly if it does happen it will 99 times out of 100 happen at tick over, the bike will suddleny make a knock sound and drop rev's (almost to 500) for a split seccond then correct its self

if i remeber correctly its also done it once or twice over the last year while ive been slowing down slowly on the bike coming to a stop as well

as i said its rare but wonder ifts being caused by a lack of back pressure on the exhaust system having race can's fitted and them also blowin at the link pipes, could it be causing predetonation of the fuel mix which and also valve bounce?
because ive run the bike like this for ages do you think i may require new vale seats fitting to the head as they may be burnt out?

[Phil-VTwin]

It could be a misfire, mine does this occasionally too!

[seb421]

Any idea of what might be causing it to miss fire mate?

[goody]

Mine does it as well, thought it was normal. It did it when I first got it and it hadn't been serviced in a while and still does it after checking valve clearances, Valve timing timing, new plugs filters, balancing the carbs etc. I thought it was down to poor fueling from such big carbs at low revs.

[Phil-VTwin]

Its probably due to fueling, i know mine is a bit rich at lower revs, search for "airbox cough" and you will find its a common quirk of the storm.

[seb421]

yeh im quite used t the 'cough' with the airbox, the bikes allways done that so wasnt worried about that, just this knocking like its droping on to the one cylinder for a revoltion that was concering me, got a week off in three weeks so wil get Damon Hill to fully go over the engine and fit my Dynojet kit

[bazza696]

yeh im quite used t the 'cough' with the airbox, the bikes allways done that so wasnt worried about that, just this knocking like its droping on to the one cylinder for a revoltion that was concering me, got a week off in three weeks so wil get Damon Hill to fully go over the engine and fit my Dynojet kit

mine coughs now and again, and I get the knock, I was putting it down to a bit of pinking due the fuelling, I was not really concerned about it. Tony mon says that his PC has put a stop to the cough, so its probably fuel/timing on idle, cause mine hunts a .lot on tick over. Just turn the idle up.

[sirch345]

Seb,
Not too sure what noise your bike is making if it's not the spit back through the carb/airbox noise as others have suggested, and you've said it's not that. Best as you say to get it checked out at a garage IMO too.

Mine does it as well, thought it was normal. It did it when I first got it and it hadn't been serviced in a while and still does it after checking valve clearances, Valve timing timing, new plugs filters, balancing the carbs etc. I thought it was down to poor fueling from such big carbs at low revs.

Goody,
Some say they've never had this happen on their Storms, while others like you, Seb, Bazza, Phil and myself have. The best info I could get on this was that the tick over was to rich (as Phil mentions) and it was gassing up. So I did back off both air screws (only by around 1/4 of a turn out for each carb) and that has helped, but not completely eradicated it.

Chris.

[Stratman]

Mine has always done that - very rarely, as you say. Had it 10 years now so I wouldn't worry too much!

[mwross1964]

Mine's has done it since the replacement engine, not all the time thou' but in low revs or when its ticking over,it sounds like its from the engine but god knows, you can feel it as well as hear it.