Hi all,

To give some background,my CBR954 was stolen a while ago. Sadly my baby was uninsured and as funds are limited at the moment, I bought a CBR400 nc23 which had been standing for some time. Well this has lead to rather a steep learning curve as it turned from a quick fix into just about a full blown restoration.

I need some guidance please as I have reached the point of turning my bike into a Molotov cocktail because she wont start. When trying to start her, she will backfire through carbs and if I continue to crank it for any period, it will then backfire through the exhaust.

So far I have tried cleaning the carbs. The coils,HT leads, plugs, battery, rectifier and fuel pump have all been replaced and I have verified that the new parts are working. The fuel is also fresh.

From my understanding the backfire indicate's a lean condition, yet if I pull the plugs they are wet?

I suspect that the problem is carb related but that being said, the jets are standard size, float height's and idle adjustment are set as per the Haynes manual. I don't know what to check anymore?

Thanks in advance
Conrad

Only time Ive experianced back firing through the carbs is when Ive been clever enough to put the wrong plug caps to the wrong plugs. Gave me a hell of a fright when it happened hehehe

As far as i remeber the coil on the lhs (as you sit on the bike) supplies cylinders 1 and 4. The coil on the rhs supplies 2 and 3.

What plug from each coil doesnt matter, as long plug caps from left goes to 1 or 4, and right goes to 2 or 3.

Hope you get it sorted.

Hi,

Thanks for the response, I double checked that tonight and confirmed the coils are wired up right.

Im not sure why I didnt think of this before, but this evening I poured a little fuel down the carb throats and she fired briefly. So Im assuming that its definitly a carb problem but Im just not sure what could be causing it. Does anyone know if there are any likely culprits that I need to check when I strip the carbs again?

Thanks

Might sound kinda obvious but make sure the carbs are clamped up nice and tight.. i had a similar symptoms when i first bought mine as a not runner. Turned out the carbs weren’t clamped up at all..

dry them plugs off using a gas cooker or the like..

then try and get it going with some carb cleaner sprayed into the airbox...