bike wont start and backfires

beaunc30 · Post by **beaunc30** » Sat Jan 21, 2012 3:23 pm

hi could anybody give me any ideas as to what could be wrong with my bike it has sat in the shed for a couple of months but has always been started regulary, i started it today and it started fine switched it off then left it about 5-10 mins then started it again and didnt seem to run very well as if it was only firing on 3 cylinders then it would only run with the choke fully open but only just, checked all plugs are sparking and they seem to spark fine, checked all breathers and took the top of airbox off everything seems ok but now it wont start at all just backfires now and then i am completely confused to what it could be.

spud · Post by **spud** » Sat Jan 21, 2012 3:48 pm

might seem a silly one but have you checked to see if its geting petrol , (ie) vacuum hose on the tap to the cylinder head as these can come off and brake down over time , and give the earth points on ur bike a check over in case you have painted any brackets and geting poor earth , but im sure wont be long till some one with alot more know will come and give you a hand

spud

beaunc30 · Post by **beaunc30** » Sat Jan 21, 2012 3:53 pm

thanks for your help all pipes etc seem to be fine im pretty sure in thinking that if its backfiring its getting petrol think i might get myself some new plugs and give that a try

scotjell · Post by **scotjell** » Mon Jan 23, 2012 1:20 pm

Possible CDI problem, if replacing plugs check each one for a spark. Had similar problem tried all sorts and luckily I had a donor NC so borrowed the CDI and started first time. Graeme France on here does CDI's if you need one.

Post by **CMSMJ1** » Mon Jan 23, 2012 6:04 pm

Plugs...always is!

Post by **Morespeedvicar** » Wed Jan 25, 2012 2:31 am

CMSMJ1 wrote:Plugs...always is!

Damn he beat me to it!

Try taking the plugs out and putting the tip into a gas cooker flame or a blow torch, dry them out. Maybe give them a wire brush aswell.
Cheers
Ian

beaunc30 · Post by **beaunc30** » Thu Jan 26, 2012 9:41 pm

changed the plugs for some nice new ones today and it started first time and runs like a dream :)

Post by **CMSMJ1** » Thu Jan 26, 2012 11:06 pm

W00t. Always the plugs man...

Jashdown · Post by **Jashdown** » Fri Jan 27, 2012 12:44 am

Whyyyyy does it always have to be the plugs when they are so expensive! Places in Aus sell them for $30 a piece.

scotjell · Post by **scotjell** » Fri Jan 27, 2012 12:30 pm

There's a guy on flea bay sells them for around £7 each!

bike wont start and backfires

bike wont start and backfires

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