So I've been throwing wrenches and elbow grease at my CBR1000F SC21 for a few months now and I've finally come to the point that everything should come together.

Last weekend I replaced the head gasket, reinstalled the head and everything attached to it hoping to get back in the saddle on the weekend (since the weather had been lovely). But alas, she won't start.

At first when I remounted the carb and pushed the starter she came to life, albeit a bit stumbly. At the same time gasoline also poured out of the thing. I suspected a stuck float needle so I pulled the carb of, cleaned the bunch, check the operation of the floats and remounted the carbs.

Ever since that last remount she just won't start. I've taken the carbs off again, cleaned all the jets and everything I could reach with copious amounts of carburettor cleaner and a small brush. Also checked the spark and that seems okay.
When I now push the starter it sounds like the engine almost starts but just not quite.

I'm at a loss, anyone got ideas?

 

Check the primary and secondary resistances of the coils to see if they're both the same (maybe do the stick coil upgrade at the same time) or even check to see if there's a spark with a plug grounded to the rocker cover bolt, pull the diaphragm pipe off the petcock and suck on it to check if the diaphragm is operational in the petcock and fuel is coming through. LASTLY Whip the plugs out to check they're not damp. If they are burn them over a cooker flame until warm and dry and put them back in before turning it over. All basic checks really.

My choke was stuck and would not operate and the effect it had was almost trying to go but not quite catching. Although this one hadn't run for nearly 2 years after being left in a field!!! I pulled across the choke bar on the carbs and up she went. You have to remember too that if the top end has been off and the tensioner too then you may need it to be full of oil and actually tensioning the chain or the cam timing may be a little out.

The above advice is just my opinion, I am not a mechanic!

 

I'd say, double check the cam timing. My money is on one cam is out a tooth.

 

I think I owe you a drink. Both cams, 1 tooth out.
Unfortunately, still a no start.

 

Legend.

 

So still a no start but I have concluded this:
Air is leaking out of (I assume) cylinder 4 because when I crank the engine by hand I hear quite the hissing noise coming from the right side of the engine on the compression stroke of cyl. 4. Also when starting the engine the crankcase ventilation seems to blow quite a lot of air.

Tomorrow I'm tearing her up again to poke around hoping to find what may be wrong.
Any pointers would be greatly appreciated though.

 

How about the stubs which get used to balance the carbs, if the blank is missing it will be puling a vacuum on that pot.