Topic: Hard Starting

[gaillarry]

1978 CB750K - Just overhauled the engine and when the bike runs, it sounds great with lots of power, BUT it's a bugger to start.  I had to use ether in the airbox to get it started.  Once running and warmed up, the bike will restart no problem, but after sitting for 30 mins it won't start without a burst of ether - any suggestions?   I've also noted that #2 exhuast pipe is not as hot as the other pipes?

[don_m]

About then the EPA required cleaner burning engines & it is typical that motorcycles using butterfly chokes such at these to be very cold hearted.  Many have sealed or limited adjustment to the idle mixture.  One thing that helps is to set the choke on full & open the throttle full while cranking a couple of turns of the engine to prime it.  Then close the throttle with the choke still closed & crank it again.

[Harry]

Try cranking with chole engaged and kill switch on (to prime). Wait a few seconds, disengage kill switch and try again.

[jesse]

the 77 and 78 have an accelerator pump built on to the number 2 carb.with the airbox off twist the throttle several times to see if the pump is squirting fuel into the carb throats.if not then you need to clean the pump or replace diaphram.

[eldar]

I am working out this problem too. My #2 was running to rich. I corrected my screw up with the accel pump and that has helped. I eyeballde my points gap and timing so I need to correct that. Even so now though, my bike takes off after cranking for a second or so. Hell starting with the kicker is easy.
I would say to make sure all carbs are bench synced first then set the idle screws out 1.5 turns. Also make sure the choke is set correctly. The flaps should be full open when the choke is NOT engaged.