Topic: CB550 Wont start ffter short ride and short stop... Reverse choke and it Starts?

[Fraserimoore]

Hi Guys,

As the Subject states:

Went out on my CB550 for roughly 10-15mins. Stopped off for a brew and after 30mins of it sitting I went to start it up and it wouldnt fire.

Should I be needing the choke after such a short stop? I was using the choke and then decided to try with the choke off and it fired straight up?

Does this sound ok or am I possibly running too rich?

A bit about my bike:

Pods, rejetted with 40slow and 110main, float height correct
Carbs bench sync'd, all timing and valves set/adjusted correctly. Plug chops done to the best of my ability.

It seems to idle and ride absolutely fine (to me anyway...a novice) Plugs are perhaps a little carbon fouled.

The only thing I haven't done it adjusted the needle clip (currently at stock). Would moving the clip up 1 / dropping the needle perhaps lean it out a little?

Cheers Again

[flybox1]

Shouldnt need any choke on a hot engine.  If its been sitting for a while, it might need partial choke.
My 550 would cold start with full choke and then need it taken off immediately.

[calj737]

Pods, rejetted with 40slow and 110main, float height correct
Plugs are perhaps a little carbon fouled.
Would moving the clip up 1 / dropping the needle perhaps lean it out a little?

A smaller main jet would be my choice if the idle plug chop shows good plug conditions. That would get you closer to "lean" then use the needle position to fine tune. Its much harder in my opinion to take rich fuel out using the needle because its a specific volume of fuel. Minor adjustments of the jets and screws make it easier to dial in the correct A/F mixture from my experience.

[Fraserimoore]

Cheers for the quick response guys.

Both giving answers which I was sort of hoping for.

Good thing thing I've got lots of size jets to play with. I'll take the main down 1 size and see how it's goes.

As for my cold start, I'm exactly the same, the choke goes off immediately once it fires. It's probably just my novice error and habit to place the choke lever back in the up position every time I stop and then I forget and start scratching my head wondering why it won't start, DOH!

[Bankerdanny]

Choke on makes the mixture richer, so too rich wouldn't be the problem.

15 min isn't a long ride and if it's chilly enough out, and also if there is a good breeze, the engine could cool enough to need choke to start again.

I wouldn't worry about it if your bike runs and idles well.

[HondaMan]

A 110 main jet in a 550 is mighty rich, so I suspect the plugs were still 'wet' from the ride when you tried to restart. This makes the spark weak until you get them to burn again for a minute or so: it effectively "shorts out" much of the spark energy when the plugs are wet or carbon-fouled.