RRJ wont play nice

[hondaguy]

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

[jac_is_smiling]

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.

[hondaguy]

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

[Townsend87]

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..

[CMSMJ1]

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...