Motorcycle Repair: 1982 honda nighthawk 650, honda nighthawk 650, 1982 honda nighthawk

Question
I finally got my nighthawk 650 running, and put a new battery in it and cleaned the carbs, but i cant get the bike to fire on all four cylinders... it is mainly number one cylinder that isnt firing, but number two isnt very strong... i have both gas and spark for all cylinders, but when i put my hand over cylinder 3 and 4 pipes it echoes and the air coming out is warm, but number one and two cylinders doesnt have a strong air flow, and the air coming out of the pipes are cold... is there any way you can diagnose this or give me an idea where to start at fixing the problem?

Answer
Hi Jake,  well this is not one of my better known models, but it does sound like carburation is still the main problem.  However to be sure, I would remove all the spark plugs and evaluate the running condition of each cylinder.  While they are out, do a compression test.  If the compression is within 10% of each other, then the carbs will have to come off again, and you will need to identify the slow/medium running jets and make sure these are cleaned thoroughly.  You may need to purchase a manual to identify the right circuit, and also check that the jet size is correct by sizing it; sometimes the hole is there, but constricted with residue, this will affect the running significantly.

Good luck,  Jan