Topic: Cold starting

[climbingaz]

I just recently got my '78 750k all roadworthy and have started to venture out around for short rides to get all the kinks worked out.  One thing I've noticed is she is very cranky in the mornings when I try to start her.  Once I do get her started and she's warmed up, I usually never have a problem re-starting her.  I know it's a 33 year old motorcycle and I'm not expecting miracles, but do you have any pointers or suggestions for getting her going on those cold mornings?

p.s.  all stock, with airbox, carbs have been cleaned half a dozen times during the rebuild.

[flybox1]

CLEAN!  
nice build!
my 350F is that way too.  
i can only suggest to keep a good charge on the battery, and up to date on all your maint.

BTW, what seat/tail light combo is that?  it flows really nice.

[vanillagorilla]

I got the same issue... Couple squirts of starting fluid dont the velocity stacks makes things much easier. I am hoping that the lack of backpressure was affecting mine, we'll see if my new muffler helps.

[climbingaz]

CLEAN!  
nice build!
my 350F is that way too.  
i can only suggest to keep a good charge on the battery, and up to date on all your maint.

BTW, what seat/tail light combo is that?  it flows really nice.

Thanks!  Still got a lot I want to do to it, but version I is done.    The seat/tail is a custom piece made by Benjies Cafe Racers.  At about $400, it was 4 times as much as I paid for the bike to begin with  , but it was the only one I really liked that fit with the '78 stock tank.

[climbingaz]

I got the same issue... Couple squirts of starting fluid dont the velocity stacks makes things much easier. I am hoping that the lack of backpressure was affecting mine, we'll see if my new muffler helps.

Hmmmm....that's got my thinking.  I was experimenting with the muffler baffle.  Had run it without the baffle on a few rides but gave up after losing half the hearing in my right ear  .  Perhaps it was too free-flowing and not creating adequate backpressure?

I did put the baffle back in this past weekend and had the same issue, but thinking it might have been worse without the baffle.

Unfortunately starting fluid isn't an option for me using the stock airbox.

[vanillagorilla]

I got half a mind to go out and see if its easier to start, but the other half is reminding me there is a 17 degree wind chill. I guess I'll find out eventually.

[flybox1]

check your plugs after it idles for a bit. 
your A/F mix might not be optimal.

[bollingball]

climbingaz you can give it a spray in the slot on bottom of air box. This does not fix your problem but it will tell you something try it and report back.

[Nikkisixx]

I think the choke setup is just a little more finicky on the PD carbs, and takes a little fiddling to get just right.  I have found that "pumping" the throttle before hitting the kicker or starter richens the mix a bit and makes my '78 less #$%*y when she is cold.  You've got an accelerator pump, might as well use it 

[climbingaz]

I think the choke setup is just a little more finicky on the PD carbs, and takes a little fiddling to get just right.  I have found that "pumping" the throttle before hitting the kicker or starter richens the mix a bit and makes my '78 less #$%*y when she is cold.  You've got an accelerator pump, might as well use it 

It does seem much more sensitive to choke use than other bikes I've had.  My initial routine has been (full choke, no throttle) but she doesn't seem to like that.

Great suggestions so far, thanks!

[flybox1]

have you check'd for vac leaks at carb to engine boots?

[climbingaz]

have you check'd for vac leaks at carb to engine boots?

Brand new boots installed last month....but I'll double check the clamps again.

[madmtnmotors]

My 78' 750 is pretty fussy after sitting for two weeks or more. Two twists on the throttle while setting the choke (there is an idle ramp on the choke linkage, opening the throttle makes for an easier pull on the choke cable). I usually start at 3/4 choke and adjust it to keep the idle around 2800/3000 till it warms up, usually five minutes or so. If I know I'm going to ride the next day, starting it the night before makes for a shorter warm-up the following morning.

[Bill K]

  My 78K was giving me one hell of a time cold starting. Turns out one of the choke valves were misaligned on the choke shaft not allowing FULL choke when cold starting. This was something I inadvertently done while cleaning the carbs. After fixing this I barely bump the starter and it fires right up. I beat my brains out and finally found it was something this simple. Good luck!

                                                                              Bill K

[vanillagorilla]

Interesting...
Might have to take a look at that sometime!

[climbingaz]

Just an update...

Adjusted my valves and redid the ignition timing and she fires right up.  I think it was the ignition timing.  Gotta love these old bikes. 

[mbzak]

Cold starting and "cold-bloodedness" is helped with better ignition than just points.  HondaMan has a great ignition setup (see the top of the classified section) or you could go more expensive Dyna-S.  Something similar to the Dyna-S (I think) is the Pamco.  The K7 and K8s are more cold blooded than the earlier ones...

[yo2001]

  My 78K was giving me one hell of a time cold starting. Turns out one of the choke valves were misaligned on the choke shaft not allowing FULL choke when cold starting. This was something I inadvertently done while cleaning the carbs. After fixing this I barely bump the starter and it fires right up. I beat my brains out and finally found it was something this simple. Good luck!

                                                                              Bill K

I found the same with my cb350. I had to reset the choke flaps by setting the #1 and match the rest so all the flaps are close fully. now it'll crank even in the teens with about 3 kicks. I'll choke fully then crank and soon after, I'll open the choke slightly to get the motor to take in some air and boom, fast idle.