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Discussion Starter #1
Hello to everyone I'm a new rider and a new member here!

It doesn't seem like a huge problem, but it's weird and it's bugging me so I wanted to hear from the experts.

I have a 1973 Honda CB450. It starts and drives fine. The only problem is that it doesn't start with the choke closed. It only starts when the choke is open.

It's not really an issue in terms of riding, but I was curious as to why this is happening. I recently cleaned the carbs too.

Any thought?? Thanks!
 

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Welcome Stu! Several of us here have had one of those so hopefully we can help you!

For clarification, the bike will only start with the choke closed you said.. is that choke on or off? Butterflies open or closed? Just making sure..

Any change whether the bike is cold or warm?

What mileage do you get roughly?
 

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Discussion Starter #3
By choke closed I mean the butterflies closed, so no air coming in.

It doesn't seem to matter if it's cold start or hot.

I'm not really sure about mileage, it doesn't seem to be out of whack.
 

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Mine will start to fire with the choke closed, and the throttle just a little open, when cold, but I have to open the choke right away to keep it running, and use the throttle to keep it running until it is warm enough to idle. There is a spring-loaded door in the choke plate that is supposed to do this for you, but it doesn't help mine.
 

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Discussion Starter #7
Oh so mine isn't the only one that has trouble starting with the choke closed huh

It still really doesn't make sense though...

Isn't the point of closing the choke to make the fuel mixture rich and help the start?
 

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Yes, it makes it rich enough to start, but, once it starts, it is way to rich to keep running, even when fairly cold.

Of course, if your float levels are too high, you could be too rich for the choke to begin with.
 

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Discussion Starter #9
So basically if the bike starts with choke open then it's not an issue right?

I wouldn't have to worry about bike not starting with the choke closed?
 

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If you don't need choke, you don't need it. I just use mine to get the fuel flow started sooner, then only when it's cool. If it starts too easy without choke when cool, your float levels may be a bit high.
 

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There is a reason why the manufacturer puts it there. It doesnt mean you necessarily need it. But, it's there in case you do. Ex: During summer you might not need it and during winter you do. I dont use mine but mine is an enricher/ not a choke. What you should be concerned with is the condition of the engine and the way it runs (lean or rich).

So basically if the bike starts with choke open then it's not an issue right?

I wouldn't have to worry about bike not starting with the choke closed?
 
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