rear cylinder missfire
 

Hi all. newbie here! :oops: ive been reading the forum for a couple of months now and found many items of interst/to be of great help. Brilliant site!
ive had my svs (99) for 3 months now after passing my DAS 2 months ago (having previously ridden 125s for a few years), and it has recently developed a misfire from the rear cyclinder. it more often than not sounds likes its external (top of the cyclinder) but when cold it can pop and fart from the exhaust. it only happens at low revs (idle on slight choke when cold) and when 'blipping' between 1400 and 2500rpm when running nice and hot. would this possibly be a spark plug fault? or something more major? the previous owner insisted he had just fitted new spark plugs and oil + filter. the bike has done 11000 miles only
Hope someone can be of some guidance
thank you all, and i hope that one day too i can be of help to newbies like me. this site even made me choose an SV!!

oh yes i forgot to mention i have also had it running once on just the front cyclinder after the bike had been sat in the garage for 4 days. i went and toppped up the tank(live opposite petrol station! :wink: ), and went 1/2 a mile down the road after a lot of backfiring, and all became normal! (possible maybe that fuel line some where is blocked?)

oh yeh.... i had to replace my caliper seals, and after reading on here that some of you have found this to be somewhat expensive, i manage to get the seals for one caliper (dust seal o-rings x2, and main piston seals x2) for £12.95 from DPL in doncaster. initially i thought i was going to have to pay £40 for two 'kits' :shock: thank god i was stubborn (or is that just tight?! :? ) and shopped around for a while! if anyone wants there contact details i would be happy to help

eyup Sdicko!

Hows Selby nowadays? I lived in Howden but worked around there.

I had this problem with my K2, It was an intermittant fault though.

First have a look at the plug, the seller told you he fitted new plugs, maybe he hasnt got the cap on properly, or even the plug is loose. The rear one is simplicity itself compared to the front one :P

When I eventually found the fault on mine, it was the low tension wire from the coil chafing on the frame. The dealer said it had been misrouted at the factory :cry: after trying to blame someone else who serviced it.

I found mine by trial and error, you might be able to go straight to it now.

Enjoy your SV

The other thing to check is the choke cables, and the back one seems to be more of a problem than the front.

Undo the screw that holds the plunger/cable end into the carb and carefully draw the plunger out. Corrosion is the culprit. Clean any white crud off, lube cable well, I use silicone rubber&plastic lube (aerosol from Halfords). Check plunger slides freely in carb.

If it is cruddy, might also be worth checking front one too, though that really needs the carbs off to do it (possible without, but very tricky).

sd1cko you want to cut down the size of your avatar a bit.

If you want to add something that large, add it to your signature as it doesn't bugger up the page layout for everyone.

Cheers Mark.

mine does the exact same thing too, so hopefully what wheelnut said will fix it, its been bugging me ever since i bought it!

by the way wheelnut where is this coil and wire so I can look for it?

thanks all for the suggestions.

unfortunately Wheelnut, Selby is still the same boring place as ever with always increasing houseprices (£90k + for a 2 bed house in the rough areas!) and decreasingly little jobs (average wage is £16k :cry: )! I suppose living in a popular biking area with little police presence is definately a bonus though! (and then theres the sherburn meet on sundays!)
Will check the possible wiring problem this weekend, seems a logical start as the sound sometimes seems external

as requested i have also removed my avatar until a smaller one is found :D sorry for any inconvenience caused