Choke doesn't choke

[TheNose]

I rebuilt my carbs and put new o rings in them. Before the rebuild, I could apply the choke and it would fire right up. Now, I have to crank for a long time before it will fire. Does anyone have any ideas? I have the Mikuni VM carbs that have a choke like this -



This is not the carb that I have, but the choke looks like this.

Thanks,

Terry

[robinjo]

Are all four chokes engaging or just the one at the handle?
The choke mechanism itself is really simple and allmost impossible to plug up with dirt or rust particles. Idle speed and mixture set correctly?

[Sandy]

One thing often overlooked is the tiny orifice at the bottom of the choke reservoir in the float bowl, that's the tubular reservoir in one corner of the float bowl. This supplies fuel to the choke tube and plugs quite easily. Because it's in the float bowl and not on the carb it is often overlooked.

[TheNose]

Are all four chokes engaging or just the one at the handle?
The choke mechanism itself is really simple and allmost impossible to plug up with dirt or rust particles. Idle speed and mixture set correctly?

Yes, all four are engaging. The idle speed is correct and I used a colortune on the mixture. Should I adjust the Pilot screws on the bottom?

Thanks,

Terry

[TheNose]

One thing often overlooked is the tiny orifice at the bottom of the choke reservoir in the float bowl, that's the tubular reservoir in one corner of the float bowl. This supplies fuel to the choke tube and plugs quite easily. Because it's in the float bowl and not on the carb it is often overlooked.

I soaked the carbs in cleaner, so I can only assume that they are clean. Im trying to avoid pulling them again. I will if I have to, but I hoping it will be something simple.

Thanks

Terry

[TheNose]

Maybe Keith is back now, so ... bump back to the top.

Terry

[flyingace]

If you remove the plugs, choke the bike and spin the engine, do you see/smell gas vapor?

If yes, I would suggest jumping the bike with cables from a car (not running) to eliminate a weak battery as the problem. Probably not what it is, but it only takes 5 minutes.

If no, make sure you have fuel in your float bowls. This eliminates petcock and/or needle and seat problems. Beyond that, you will need a carb guru.

[retrex]

[quote="TheNose"]

I soaked the carbs in cleaner, so I can only assume that they are clean. Im trying to avoid pulling them again. I will if I have to, but I hoping it will be something simple.

Thanks

Terry

Sandy wrote:
One thing often overlooked is the tiny orifice at the bottom of the choke reservoir in the float bowl, that's the tubular reservoir in one corner of the float bowl. This supplies fuel to the choke tube and plugs quite easily. Because it's in the float bowl and not on the carb it is often overlooked.

Dipping in Carb cleaner even overnight does not necessarily open gummed up passage ways. I have soaked overnight and found that blockage is still an issue. You really need to shoot carb cleaner through all the carb circuits and note what happens to be assured all are flowing freely. Poke out the goo as necessary. The choke circuit is especially prone to clogging due to the way it is situated as Sandy pointed out. You may have to bite the bullet and go back and redo the cleaning. I hope you read the carb cleaning papers on this site and followed them to the letter. Read twice and clean once. Good luck. Oh and one final thought. Did you check your throttle stop to see that it was letting in enough air? An engine does not live by gas alone.