Backfire ?

Author
Discussion

Marshy98

Original Poster:

169 posts

224 months

Thursday 19th March 2009
quotequote all
Hi

Gave the car a run at Snetterton on Monday and it went a treat, when starting it from hot i had a big backfire through the air box, on closer inspection its scorched the carbon fibre, looks like it came from the small black hose that comes from the carbs into the bottom of the airbox, what does this hose do and what might have caused it ?

Marshy

DarioT

277 posts

216 months

Thursday 19th March 2009
quotequote all
mine backfired through the air cleaner once. no great problem... given that it was once in 2.5 years.

likley it was a miss fire caused by an errant spark. the engine ignition operates on a wasted (or lost) spark principal.

so that each coil fires twice and only one of those times in it in the right place. the other time is on the exhaust stroke..... go figure!

it could have been a kick back when trying to get over TDC when hot and it ran the wrong way for 1/2 a rev.

just my 2p

Edited by DarioT on Thursday 19th March 19:51


Edited by DarioT on Thursday 19th March 19:52

ScottHughes

262 posts

201 months

Friday 20th March 2009
quotequote all
That black hose I think is the fuel return.. but only operates if you have a sticky float.. I had to strip my carbs down last week as when I turned the ignition on it filled the air box full of fuel...