Topic: cold start problem,

[royroy]

Hi there everyone,
I need some help i have a cb650 Thar wont cold start, it run starts easily and wen warm starts with no problem is the choke important mine doesn't seem to work cable not right please all help is appreciated.

[evanphi]

Yes choke is important. I don't know your bike specifically, but usually full choke to get it started, then back off gradually while holding the throttle open to about 2.5K RPM. Do your carbs have a fast idle cam? Enricher circuit? Those may need attention as well...

I'm sure others more knowledgeable to the CB650 will chime in... but yes the choke is important!

[Moffman]

I knew before opening the thread it was going to be about a CB650 as a fellow owner. These bikes are notorious for poor cold start performance. The choke is very important and without it would make starting the bike miserable at least in my opinion. Mine bike has always needed a good 5 minutes with vary degrees of choke and adjusting the throttle stop. Majority of the time I'm starting my ride with the choke on at least a quarter.

The choke is pretty simple, its just a cable that runs from the choke knob by the gauges along the frame under the tank and then is held in by depending on the year either a plastic or metal tab. You can see here it in this pic, it's the black piece in the bottom right.

[royroy]

That pic is exactly what mine looks like my cable caseing broke off just under the plastic knob buy the clocks
Going to remove it tomorrow and see what can be done need to keep the knob as i the whole bike is original.
I need to check if the butterflies are closing properly, as im a new owner to the bike haven't gotten the nack of it just yet.