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Discussion Starter · #1 ·
After looking at the AC parts diagram for the CV carb and choke system, I think I've come up with a solution for the hot start, high rev issues. As you know, the choke will engage and apparently remain engaged for a specified period of time whether engine is cold or warm. In oder to avoid the warm start problems with the choke, I plan to put an in-line switch in the circuit for the wire to the choke. Thus disabling the choke when the engine is warm. It looks like the wires connect with flat connectors which will make it easy to do. I'll need to put several inches of lead on either side of the switch in order to locate and secure the switch where I want it and have enough wire to get to the choke connections. Tomorrow I'll track down a weather proof switch and look for a good place on the ATV to put it. When I'm done and tested the set up, I'll post results.
 

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That is a very good idea! You would think Cat or Suzuki would have thought of that???
 

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Good stuff thumbguy ... you would think that this far down the road with these bikes/engines and for the price they would put a little more engineering into them.
 

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Sweet idea, can't wait to hear the results.

Nice thinking!
 

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I believe you need to have power to the choke for it to start the slow choke opening procedure. I believe it works like a zone vavle on a heating system. Once power is applied the valve starts to slowly open. On my 05 500 with this set up one day in the winter my boys left the key on after checking the time. When I went to move it later It would not start but would turn over fine. Waited 15 minutes for the choke to reset and started right up. You might want to reconfrim this before you waste the time putting in a switch. Just shut the bike down then turn the key on and start it up after 10 or so minutes it should not High idle. Just my experience with this set up on my 3 bikes with the electric choke.
 

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but in that 10 min period the hour metor is still clicking away, i was thinking the same thing as i was reading, just turn the key on and wait a bit. worth a try i guess!
 

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Ive been thinking about modifying my choke also. I would just like to lower the rpms when the choke is doing its thing. It rev's way too high on a cold motor.
My 03 has a manual choke and to tell you the truth, it works better, or at least I like it better.
I believe the only way to keep choke off is to keep electicity going to it all day, like mentioned earlier (correct me if I'm wrong) I'll keep watching this post, I am very interested in how this turns out.
 

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Discussion Starter · #8 ·
<div class='quotetop'>QUOTE (650 Crazy Cat @ Jan 19 2007, 10:07 AM) <{POST_SNAPBACK}></div>
I believe you need to have power to the choke for it to start the slow choke opening procedure. I believe it works like a zone vavle on a heating system. Once power is applied the valve starts to slowly open. On my 05 500 with this set up one day in the winter my boys left the key on after checking the time. When I went to move it later It would not start but would turn over fine. Waited 15 minutes for the choke to reset and started right up. You might want to reconfrim this before you waste the time putting in a switch. Just shut the bike down then turn the key on and start it up after 10 or so minutes it should not High idle. Just my experience with this set up on my 3 bikes with the electric choke.[/b]
When you first tried to start the engine, did you use the primer on the carb at all? If not, give that a try next time. I bet the engine starts right away. These electric chokes are haywire at best.

The objective of installing the switch is to avoid having to wait for engine rpm to drop after starting a warm engine. Waiting ten minutes to start the engine is even less appealing. When the engine is warm, no choke should be required to start the engine. By cutting power to the electric choke, I should be able to start a warm engine without choke assistance and not have the engine revving so high. No different than with a machine equipped with a manual choke. In fact, with the choke engaged during warm engine starts, you're just burning more fuel unnecessarily.

As far a a progress report goes, I don't have one yet. I spent half an hour looking for the choke wire connection and an easy way to access it. The diagram is much simpler than the actual machine's wiring. It looks like I have to take off the air box to access the wire to the choke. It's very cold here and I'm not too keen on freezing my a$$ off to do it. I'll wait for a warmer day. If any of you are in a warmer climate and you're interested in trying it, let us know how it goes. You can also ask your dealer/mechanic what they think of putting in a switch. Good luck.
 

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I must be weird or mine dont work like your guys ACs do,i start mine when its cold and it hits the choke and works good, when the motor is warm i have not ever noticed my choke working for more than a couple seconds and one blip of the throttle when kick it right off...??? guess iam lucky :D i like they way the choke works only had trouble with it when it had dirt in it and this was not the atvs fault it was mine for rideing in the stuff i do....
 

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Discussion Starter · #10 ·
<div class='quotetop'>QUOTE (CFM-Z440 @ Jan 19 2007, 12:45 AM) <{POST_SNAPBACK}></div>
That is a very good idea! You would think Cat or Suzuki would have thought of that???[/b]

Would have been a great idea if the electric choke worked opposite to what I hoped my plan was to do. Check the attached link to find out why my plan will not work and why one of the other suggestions might.

http://www3.telus.net/dougsimpson/CVcarb.html
 

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Discussion Starter · #11 ·
<div class='quotetop'>QUOTE (tiggershark @ Jan 19 2007, 12:01 PM) <{POST_SNAPBACK}></div>
Ive been thinking about modifying my choke also. I would just like to lower the rpms when the choke is doing its thing. It rev's way too high on a cold motor.
My 03 has a manual choke and to tell you the truth, it works better, or at least I like it better.
I believe the only way to keep choke off is to keep electicity going to it all day, like mentioned earlier (correct me if I'm wrong) I'll keep watching this post, I am very interested in how this turns out.[/b]
I've been doing more research on electric chokes. From what I've been reading, they are frequently subject to failure and the excerpt below explains ways to get around the electric choke. Fortunately for those of us with problematic chokes, the carburetor has a primer built into it. As a matter of fact, when I went to start my Cat after two and a half months of sitting idle, it wouldn't fire until I used the primer. I also have an old two stroke, dirt race bike with a primer only, no choke and kick start. It has worked flawlessly for many years. Sooooo, I'd say that if we use the primer, we might not need the electric choke at all. I'm going to find the easiest way to temporarily disable the electric choke to see if I can get it to operate using the primer only. If it works without it, I permanently disable it.

Below is some good reading on electric chokes. Have a look and let us know if you'll be giving the electric choke the boot. If you do, let us know how things work without it.

Eliminate automatic choke. Most of the GY6 scooter engines seem to come equipped with the Keihin style CV carburetor with automatic choke. In theory, this is a nice feature - the choke turns on by itself when needed and then shuts itself off - assuming it all works properly. Unfortunately, the automatic choke on these carbs seems to have a tendency to stick ON at times. As a result, the air/fuel mixture will be way too rich. This KILLS performance. There are a few ways to deal with this... one is to just remove and block off all passages in the carb for the automatic choke. An epoxy such as JB Weld can be used or one of the epoxy putties commonly found in automotive stores. If you primarily drive in warm weather, then the choke may not be needed anyway. However, if you drive in cooler climates, then you may need a way to richen the mixture so that you can get your engine started easier. Getting a whole new carburetor with a manual choke is one idea. Some of the newer Dazon buggies (go karts) are supposed to come with a manual choke carb on their GY6 engine. Also, a Mikuni TM24 carburetor can be used as a substitute, but since it's a slide carb then the throttle cable will need to be modified or replaced. The TM24 carburetor (or other manual choke carbs) also may require a spacer on the intake manifold to help the float bowl clear the engine shroud underneath. Another way to get fuel enrichment on a stock carb with choke removed is to add one of the plunger primers that are made for use on snowmobile or ultralight engines. This primer plunger can be pumped and squirt fuel into the intake and help with cold weather starting. A small 1/8" fitting needs to be added where the fuel is squirted into the carburetor or intake manifold. Also, a 1/8" hose needs to be added to supply fuel to the plunger primer. This supply line can be T'ed off the main fuel line or fuel can be tapped off the float bowl or however it works best on your application.
 

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I just thought of something...

Your idea will not work. The choke comes on when the temp of the wax inside it drops. It uses power sent to it from the engine to heat the wax which will slowly shut the choke off.

I would just leave it be. It doesnt harm anything in my opinion. I work on them for a living, and I have yet to have a problem with one that wasnt caused by someone removing it.
 

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Discussion Starter · #13 ·
<div class='quotetop'>QUOTE (CFM-Z440 @ Jan 21 2007, 02:56 PM) <{POST_SNAPBACK}></div>
I just thought of something...

Your idea will not work. The choke comes on when the temp of the wax inside it drops. It uses power sent to it from the engine to heat the wax which will slowly shut the choke off.

I would just leave it be. It doesnt harm anything in my opinion. I work on them for a living, and I have yet to have a problem with one that wasnt caused by someone removing it.[/b]

You are correct in saying that my idea will not work. I had already pointed that out a couple of posts back. As far as the chokes not causing problems, in all due respect, you're wrong. Having a device that activates when it shouldn't (i.e. when the engine is warm) is, in my opinion, a poor design. Having to wait a minute or more for engine rpm to drop before I can shift into gear as a result of the choke being engaged, is to me, ridiculous. Imagine getting in your car to drive to work but the transmission will not engage because the engine is revving at 3500 rpm! Would you consider that as being acceptable? Another aspect of electric choke failure is that if the choke malfunctions, it will stay permanently engaged thus causing the engine to run rich. This will have a negative effect on engine performance and will also contribute to excessive fuel consumption. Electric chokes do malfunction.

Now, since you seem to know something about the electric choke, will the choke (enrichening system) effectiveness be eliminated if the choke is removed? If the choke is removed, would covering the hole with JB weld be all that is needed to seal the system? Also, there is a primer on the carb. In lieu of the choke, will the primer be sufficient for cold engine starts?

Thanks.
 

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<div class='quotetop'>QUOTE (Borat @ Jan 21 2007, 02:40 PM) <{POST_SNAPBACK}></div>
<div class='quotetop'>QUOTE (CFM-Z440 @ Jan 21 2007, 02:56 PM) <{POST_SNAPBACK}>
I just thought of something...

Your idea will not work. The choke comes on when the temp of the wax inside it drops. It uses power sent to it from the engine to heat the wax which will slowly shut the choke off.

I would just leave it be. It doesnt harm anything in my opinion. I work on them for a living, and I have yet to have a problem with one that wasnt caused by someone removing it.[/b]

You are correct in saying that my idea will not work. I had already pointed that out a couple of posts back. As far as the chokes not causing problems, in all due respect, you're wrong. Having a device that activates when it shouldn't (i.e. when the engine is warm) is, in my opinion, a poor design. Having to wait a minute or more for engine rpm to drop before I can shift into gear as a result of the choke being engaged, is to me, ridiculous. Imagine getting in your car to drive to work but the transmission will not engage because the engine is revving at 3500 rpm! Would you consider that as being acceptable? Another aspect of electric choke failure is that if the choke malfunctions, it will stay permanently engaged thus causing the engine to run rich. This will have a negative effect on engine performance and will also contribute to excessive fuel consumption. Electric chokes do malfunction.

Now, since you seem to know something about the electric choke, will the choke (enrichening system) effectiveness be eliminated if the choke is removed? If the choke is removed, would covering the hole with JB weld be all that is needed to seal the system? Also, there is a primer on the carb. In lieu of the choke, will the primer be sufficient for cold engine starts?

Thanks.
[/b][/quote]


Depends on how cold you are talking. With nothing more than a primer, it would fire and then die if used in cold weather. I think it would be pretty unforgiving in any climate, because you would have to let it warm up before you could go anywhere. If you hit the gas it would just die.

If you want a real fix, get a carb for an older model like an 04' They still had a cable choke. There were really no other significant changes in the carb than that. You would also need a cable and lever setup for an 04'

I have never had trouble getting one in gear from the choke operation unless the idle setting was set too high. It sounds to me like you have somewhat of an extreme case, or your idle may be set too high. I bet if you turn your idle setting down just even slightly, you will be suprised in the difference it makes.

Arctic Cat was simply trying to make them idiot proof with out the expence of fuel injection. They lisen to the wrong group of complaints in my opinion. Also the only time the enrichening valve/choke makes any significant difference in the fuel mixture is when the throttle is closed. Once you are moving it has little to no effect. So that throws poor performance and excessive fuel use out the window.

So in my opinion it is not really a problem.
 

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Is there a way to lower the rpms while the electric choke/ enrichment is doing its thing? A seperate screw for the fast idle portion? I would like to tame mine down a bit. The electric choke works very well on my 05 500, just needs a little fine tuning.
I have started it in gear (brake lever pulled in) and I dont have to wait for the rpms to come down, but thats not really the right way to get around it.
 

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My choke has stuck twice. The 1st time, it cleared up witin a few minutes. That was several weeks ago. The 2nd time (Saturday), I messed with it for about 45 mins. Finally, I guess I covered the intake enough and heard a thump from the carb. It was fine the rest of the day. Does the carb need to be cleaned? I only have about 200 miles on it.
 

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My choke doses some weird stuff too but only in the winter. Some days I have to keep adjusting the idle to keep it running after it has worms up!
 

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I tried starting my H1 when it was 0 degrees outside last weekend. I had to talk nice, then talk dirty, then apologize, then cry, then laugh, go drink a cup of coffee, then look at it adoringly/angrily/respectfully, then she fired up and stayed running. NOW, I will admit that the plug was likely fouled from the prior pilot jet/exhaust combo that I had in it (55 pilot with stock exhaust...no good), so that had a play in it I'm sure. Regardless, I wasn't impressed with the autochoke at that time. The only way to keep it running was to keep priming it.
 

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Discussion Starter · #19 ·
<div class='quotetop'>QUOTE (CFM-Z440 @ Jan 23 2007, 02:31 AM) <{POST_SNAPBACK}></div>
<div class='quotetop'>QUOTE (Borat @ Jan 21 2007, 02:40 PM) <{POST_SNAPBACK}>
<div class='quotetop'>QUOTE (CFM-Z440 @ Jan 21 2007, 02:56 PM) <{POST_SNAPBACK}>
I just thought of something...

Your idea will not work. The choke comes on when the temp of the wax inside it drops. It uses power sent to it from the engine to heat the wax which will slowly shut the choke off.

I would just leave it be. It doesnt harm anything in my opinion. I work on them for a living, and I have yet to have a problem with one that wasnt caused by someone removing it.[/b]

You are correct in saying that my idea will not work. I had already pointed that out a couple of posts back. As far as the chokes not causing problems, in all due respect, you're wrong. Having a device that activates when it shouldn't (i.e. when the engine is warm) is, in my opinion, a poor design. Having to wait a minute or more for engine rpm to drop before I can shift into gear as a result of the choke being engaged, is to me, ridiculous. Imagine getting in your car to drive to work but the transmission will not engage because the engine is revving at 3500 rpm! Would you consider that as being acceptable? Another aspect of electric choke failure is that if the choke malfunctions, it will stay permanently engaged thus causing the engine to run rich. This will have a negative effect on engine performance and will also contribute to excessive fuel consumption. Electric chokes do malfunction.

Now, since you seem to know something about the electric choke, will the choke (enrichening system) effectiveness be eliminated if the choke is removed? If the choke is removed, would covering the hole with JB weld be all that is needed to seal the system? Also, there is a primer on the carb. In lieu of the choke, will the primer be sufficient for cold engine starts?

Thanks.
[/b][/quote]


Depends on how cold you are talking. With nothing more than a primer, it would fire and then die if used in cold weather. I think it would be pretty unforgiving in any climate, because you would have to let it warm up before you could go anywhere. If you hit the gas it would just die.

If you want a real fix, get a carb for an older model like an 04' They still had a cable choke. There were really no other significant changes in the carb than that. You would also need a cable and lever setup for an 04'

I have never had trouble getting one in gear from the choke operation unless the idle setting was set too high. It sounds to me like you have somewhat of an extreme case, or your idle may be set too high. I bet if you turn your idle setting down just even slightly, you will be suprised in the difference it makes.

Arctic Cat was simply trying to make them idiot proof with out the expence of fuel injection. They lisen to the wrong group of complaints in my opinion. Also the only time the enrichening valve/choke makes any significant difference in the fuel mixture is when the throttle is closed. Once you are moving it has little to no effect. So that throws poor performance and excessive fuel use out the window.

So in my opinion it is not really a problem.
[/b][/quote]

With regard to setting the idle screw, that goes without saying. If the freaking choke worked right, I wouldn't constantly adjusting the idle screw. I will be looking at an alternative method to replace the electric joke and I don't plan to buy an new carb. I might pull the electric choke to look at the interior dimensions of the needle/plunger and have one fabbed up at a machine shop and figure out an method to actuate it.

Pardon my ignorance but would you please explain how leaving the enrichening circuit engaged will not have an effect on fuel consumption or performance? I know from experience that if I leave the enrichening circuit engaged on my KLR 650 (same carb but with manual enrichener) after the engine is warmed up, the engine is sluggish and I certainly burn more fuel. You might want to do a little homework in this regard.

Below is a quote from a site that works with CV carbs. I've posted the full version previously.

4) Eliminate automatic choke. Most of the GY6 scooter engines seem to come equipped with the Keihin style CV carburetor with automatic choke. In theory, this is a nice feature - the choke turns on by itself when needed and then shuts itself off - assuming it all works properly. Unfortunately, the automatic choke on these carbs seems to have a tendency to stick ON at times. As a result, the air/fuel mixture will be way too rich. This KILLS performance.
 

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<div class='quotetop'>QUOTE (Borat @ Jan 23 2007, 11:22 PM) <{POST_SNAPBACK}></div>
<div class='quotetop'>QUOTE (CFM-Z440 @ Jan 23 2007, 02:31 AM) <{POST_SNAPBACK}>
<div class='quotetop'>QUOTE (Borat @ Jan 21 2007, 02:40 PM) <{POST_SNAPBACK}>
<div class='quotetop'>QUOTE (CFM-Z440 @ Jan 21 2007, 02:56 PM) <{POST_SNAPBACK}>
I just thought of something...

Your idea will not work. The choke comes on when the temp of the wax inside it drops. It uses power sent to it from the engine to heat the wax which will slowly shut the choke off.

I would just leave it be. It doesnt harm anything in my opinion. I work on them for a living, and I have yet to have a problem with one that wasnt caused by someone removing it.[/b]

You are correct in saying that my idea will not work. I had already pointed that out a couple of posts back. As far as the chokes not causing problems, in all due respect, you're wrong. Having a device that activates when it shouldn't (i.e. when the engine is warm) is, in my opinion, a poor design. Having to wait a minute or more for engine rpm to drop before I can shift into gear as a result of the choke being engaged, is to me, ridiculous. Imagine getting in your car to drive to work but the transmission will not engage because the engine is revving at 3500 rpm! Would you consider that as being acceptable? Another aspect of electric choke failure is that if the choke malfunctions, it will stay permanently engaged thus causing the engine to run rich. This will have a negative effect on engine performance and will also contribute to excessive fuel consumption. Electric chokes do malfunction.

Now, since you seem to know something about the electric choke, will the choke (enrichening system) effectiveness be eliminated if the choke is removed? If the choke is removed, would covering the hole with JB weld be all that is needed to seal the system? Also, there is a primer on the carb. In lieu of the choke, will the primer be sufficient for cold engine starts?

Thanks.
[/b][/quote]


Depends on how cold you are talking. With nothing more than a primer, it would fire and then die if used in cold weather. I think it would be pretty unforgiving in any climate, because you would have to let it warm up before you could go anywhere. If you hit the gas it would just die.

If you want a real fix, get a carb for an older model like an 04' They still had a cable choke. There were really no other significant changes in the carb than that. You would also need a cable and lever setup for an 04'

I have never had trouble getting one in gear from the choke operation unless the idle setting was set too high. It sounds to me like you have somewhat of an extreme case, or your idle may be set too high. I bet if you turn your idle setting down just even slightly, you will be suprised in the difference it makes.

Arctic Cat was simply trying to make them idiot proof with out the expence of fuel injection. They lisen to the wrong group of complaints in my opinion. Also the only time the enrichening valve/choke makes any significant difference in the fuel mixture is when the throttle is closed. Once you are moving it has little to no effect. So that throws poor performance and excessive fuel use out the window.

So in my opinion it is not really a problem.
[/b][/quote]

With regard to setting the idle screw, that goes without saying. If the freaking choke worked right, I wouldn't constantly adjusting the idle screw. Try adjusting your idle mixture screw to 2 1/2 - 3 turns out then set your idle speed with the engine warm at the recomended rpm. You should not need to mess with the speed all the time then

Pardon my ignorance but would you please explain how leaving the enrichening circuit engaged will not have an effect on fuel consumption or performance? Yes, when the throttle is open there is much greater air flow. The fuel added from the enrichening valve is combined with some air of its own, and the enrichening fuel circut is restricted to a pretty small hole. So when the throttle is opened there is no more additional fuel from the enrichening circut then their would be at an idle, which is very small ammount of fuel. This has little to no effect. The stock jetting is on the lean side anyway, so it certainly does not hurt. You might want to do a little homework in this regard. You might want to do the homework, I deal with this type of stuff every day! and not just on a Arctic Cat!

Below is a quote from a site that works with CV carbs. I've posted the full version previously.

4) Eliminate automatic choke. Most of the GY6 scooter engines seem to come equipped with the Keihin style CV carburetor with automatic choke. In theory, this is a nice feature - the choke turns on by itself when needed and then shuts itself off - assuming it all works properly. Unfortunately, the automatic choke on these carbs seems to have a tendency to stick ON at times. As a result, the air/fuel mixture will be way too rich. This KILLS performance. This is a pretty generalized quote, and yes, it will kill performance in the low throttle ranges, but at WOT it will not be really noticable
[/b][/quote]

Look man, Im not trying to say that auto chokes are gods gift to atv's! But they are not quite as bad as you guys describe! If you want to get rid of it go right ahead. Do a write up on how to do it. People will love it! But the auto choke has not been troublesome enough to go to all of that trouble (on a stock machine) in my opinion. I mean for christ sake, it is a Utility ATV not a race quad!
 
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