autochoke/enricher question

[indy50]

Does anyone out there know the position of the needle thingy on an autoenricher at normal operating temp(warmed up)? I am having troubles with bogging down,and rough idle. Ive already checked air filter,cleaned carb, tested coil. I was told that these autochoke devices dont work well in cold weather. Any help would be greatly appreciated.

[swampsniper]

If you take an autochoke unit and dump 12VDC across the leads, the needle should extend about 3/8", in 5 minutes.

[scooterollie]

When cold, the needle is in the "up" position, allowing more gas to flow through the enricher circuit of the carb. As Swamp said, when 12V is applied, the needle should extend, shutting off the extra flow of gas. It has been my experience that some of these shut off way too soon, not giving the engine enough time to warm up before the mixture is leaned out. If it did not extend, the mixture would always be too rich. Having not experienced this situation, don't know what that would do to engine operation.

Worth checking and a pretty simple diagnosis but your problem may be related to something else.

[indy50]

Thanks for the reply guys. When I applied voltage, the needle did nothing at all. It appears this thing will not extend. I noticed the past few days that the bike has all the symptoms of running too rich. Does anyone sell these chokes seperately? I've shopped around a bit but I can only find complete carbs. I'm thinking about replacing my carb with a manual choke type. I removed the choke and that just makes engine run worse. With the choke on but unplugged, engine runs, but I had to step the idle up considerably causing the engine to load up and eventually die. Could something else be causing this ? Thanks again for the info.

[scooterollie]

You might try Scootertronics at:

store.scootertronics.com/index.html

They don't handle Roketa but they may have the part. Would be a good idea if you could find the brand name found somewhere on the carb. "Mikuni" and "Keinhin" are two often used on these scoots.

[indy50]

Thanks for the lead Scooterollie. Scootertronics had a choke unit for 150cc carbs. I'm not sure that it will be compatible. I did find one for qmb139 at parts for scooters.com I'm gonna order it tomorrow if I cant find one locally. btw, carb has no markings as far as brand. I've had it off and apart a few times and I found no markings. I've got a parts bike (same model & yr) it has Keihin carb ,but is not completeand the parts are not compatabile with the other (autochoke& diaphragm missing. thanx lots!!

[earlwb]

I got one off of Ebay a while back.

[stewntexas]

Concerning the little Choke/Enricher thingy, this is the only part on my Helix that seems more like magic than science. I can't seem to get my head around how it works, why it works, and why it seems to work only part of the time, and there is no real way to check it out.

I see info regarding ohms in my shop manual, but the new official Honda part reads exactly the same as the original Honda part that does not seem to be working.

I'm more of a kinda ON or OFF person. If it works, then HOW and WHY, if it doesn't work, then WHY NOT, and how to determine the difference.

If I could find some type of an add-on/replacement choke for it, I would make the change quickly on my Keihin carb.

[stewntexas]

Well, it appears this topic has been here for over 24 hours without a new reply.

Looks like I am not the only one that is confused as to whether or not this part is magic or science.

[swampsniper]

There is a chamber full of special wax. It is heated by a resistance element when you turn the key on. When the wax gets hot it expands, and pushes a needle to block off a special fuel circuit, which leans out the fuel mixture. Turn the key off, the wax cools and contracts, and pulls the needle back, giving you a fuel rich mix for easy starting. To test it you apply 12VDC to the wires, and watch the needle. In 5 minutes it should extend about 3/8", about 9mm, then retract when you disconnect the power. It does not move fast, either way.

[Enviromoto]

Thank you swampsniper I learned somthing today. karma

["Big Guy"]

Had this problem 2 years ago. Don't remember who sent me the email, but it was from a dealer:

"Autochoke only works if the throttle is closed, as it operates on a separate air passage next to the throttle slide. If you open the throttle slide, no air is drawn through the passage for the choke. The wires heat a ceramic type heater that in turn causes the carb slide to drop into the carburetor, turning off the choke. Putting current to the bystarter does not cause the choke slide to rise out of the carb, rather drop slowly into it over the course of a few minutes.

To test, remove the screws that hold the unit into the carb, and lift the choke slightly out of the carb body while cranking the engine to manually choke it. If it starts, then the carb is ok, choke is not."

I wound up replacing the choke.

[indy50]

like Jeremy I also learned a bit from this thread about the autochoke. I also tried the method 250MC54 explained, I figured that if this thing is stuck in the extended position then by rraising it while cranking, the engine should start and run. I found that I didnt have carb issues and ordered another one of these perplexing little gadgets( after a couple of thorough carb cleanings), part should get here in a day or two. Oh well its a little cold for riding lately and I got an immaculate carb and some great info out of the deal!! Thanks all!!

["Big Guy"]

Now you know why I back up all my emails every month!
Glad you got it figured out...

-Rich