Hi folks, I'm approaching the final straight of my resto, I've stripped most stuff off the bike and either refurbed or replaced most stuff,

There is a spark, and fuel to the carbs but it won't start,the battery is new, I've checked the run switch is in the correct position.

I've not yet fitted the clocks.

Any suggestions please?

Thanks, Andy

BillyBarcelona wrote: Sat Jul 06, 2024 10:04 pm fuel to the carbs

Is the fuel actually getting into the cylinders?

If not, carbs are blocked. If you are and it's flooding then I'd say timing may be out.

Thanks, how does one adjust the timing please?

Andy

I am not familiar with the CB400 series so any suggestions may be completely off. As suggested by MadMotoUk, if you removed the ignition pulse rotor and did not return it to the correct position you will get miss timed spark. Also does you bike have a fuel pump. It may not be working and thus fuel is not reaching the carbies, as also suggested by MadMotoUK.

Hi, thanks for the replies, I've now checked the clutch lever cut off switch, also the side stand switch and they are both operating correctly.
There is fuel getting to the carbs as the screws below the bowls leak fuel when unscrewed slightly, as I said, there's a spark too.
I'm now at a total loss as to what it can be, the battery is not yet flat from trying, but it won't be long.
I still don't know how to access the timing on the bike, if anyone could point me in that direction I'd be grateful.

Thanks again, Andy

With the rocker cover off and #1 at TDC, cam lobes should be facing straight downwards into the cylinder on #4. Easiest way to tell if the timing is right. If the lobes are facing upwards, it's 180° out.

Thank you, if it is out,how do I adjust it? I can't see any points so I guess it's electronic ignition, but where's the distributor?
Cheers

If it's out, you need to realign the camshaft.

Sorted now folks, the spark plugs were dry, put some fuel directly into the carbs bypassing the tank , too much and it pours out of the air cleaner drain hole.

Smelt fuel when I turned it over, and in a few goes it went, I guess the engine needs to draw fuel through the petcock diaphragm but needs a little help, not run for more than 5 years and it's a sweet as a nut.

Thanks to all those who kindly gave advice, it was all useful.

Andy