Idle Issues

dylhainen

New member
I finally got my LO206 where I want it in terms of idle, acceleration and top speed. However when I start it up it sits between 2k and 2,200rpm which is fine, but once I hit the track and get up to speed I take my foot off the throttle and the engine only pulls back and stays at 3800 RPM.....so I'm breaking to slow down, but it keeps going back up. On top of that there is a corner I like to slow down in and I go to back off and not only won't it back down it accelerates back up to 4,100 RPM....So I let coast on 3800 RPM and eventually it slowly drops down back to the correct Idle speed of 2,200rpm. I have tried everything and I can't figure it out.....when you take your foot off the throttle, the throttle cable goes loose like it should so I have no idea whats going on......any suggestions would be helpful. When I pull in to stop it's sitting at 3200 rpm and I have to hold the break down while I'm shutting down the engine which is burning up the clutch...very strange
 
Have you cleaned the carb (internally?)
Also, check that your slide is not hanging up. Just because there is slack in the cable doesn't mean that the slide is closing. The end of the cable can be catching in the slide bore. This is a common problem when I see guys try to use the ball end cables in their slides. These carbs take a different throttle cable than the old flathead cables that most kart shops stock. The animal/LO206 cable has a much smaller barrel end to the cable, rather than the ball end. It makes a difference!


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🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
31 years of service to the karting industry
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
 

dylhainen

New member
Have you cleaned the carb (internally?)
Also, check that your slide is not hanging up. Just because there is slack in the cable doesn't mean that the slide is closing. The end of the cable can be catching in the slide bore. This is a common problem when I see guys try to use the ball end cables in their slides. These carbs take a different throttle cable than the old flathead cables that most kart shops stock. The animal/LO206 cable has a much smaller barrel end to the cable, rather than the ball end. It makes a difference!


-----
🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
31 years of service to the karting industry
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
ordered the right cable as I'm not sure whats on there now, but the way I see it, it can't hurt to change it. I'm going to take the whole carb. apart because I got the engine brand new in January, but never did adjust the float height and all that. Hopefully all that and ensuring the slide isn't messed up along with spraying it so it moves even easier. All this has got to solve the issue
 
ordered the right cable as I'm not sure whats on there now, but the way I see it, it can't hurt to change it. I'm going to take the whole carb. apart because I got the engine brand new in January, but never did adjust the float height and all that. Hopefully all that and ensuring the slide isn't messed up along with spraying it so it moves even easier. All this has got to solve the issue

Absolutely you need to set the float height and drop -- it is not preset from the factory. There are several other minor mods. you can make that will help as well, but let's get this thing up and running properly first. :)

FWIW, this is why many racers choose to purchase a race-ready engine package...so they don't have to do much of the work themselves. Nothing wrong with either approach. You certainly save some money if you can assemble and tune the engine yourself rather than pay an engine builder to do that for you. The downside is that you will run into some snags in the early part of the learning curve that could cost you on race day, or by damaging your engine. The builders' assembly and tuning experience is often worth the extra money.
 

dylhainen

New member
Absolutely you need to set the float height and drop -- it is not preset from the factory. There are several other minor mods. you can make that will help as well, but let's get this thing up and running properly first. :)

FWIW, this is why many racers choose to purchase a race-ready engine package...so they don't have to do much of the work themselves. Nothing wrong with either approach. You certainly save some money if you can assemble and tune the engine yourself rather than pay an engine builder to do that for you. The downside is that you will run into some snags in the early part of the learning curve that could cost you on race day, or by damaging your engine. The builders' assembly and tuning experience is often worth the extra money.

Also, I noticed while setting idle and mostly throttle and acceleration on the stand, changes when I drive the cart. Is this normal, because it makes it hard to set the throttle to where you want it. I thought you could set it up properly on the stand where you want it, then it would do the same when you drove it, but in my case the weight of the driver, changes the setup, so you literally have to set it up while someone is sitting in the seat. Is that normal?
 

flattop1

Dawg 89
No not really . It's going to change some as it warms up .
The throttle cable could be an issue as stated if it's the ball end . You need to go through the carb set the float height and drop . Then set the idle air screw as recommended . The idle speed it needs to idle that's about it . Your not racing on the stand , trying to tune the carb on the stand is hopeless .
Briggs racing has a tutorial Steve Baker and Jimbo or Brian have explained it multiple times in the Lo 206 Fourm . It may even be a sticky . Also search lo 206 carb setup with the search function in the upper right hand corner .
 

dylhainen

New member
Ok, I set the float both height and drop. Adjusted valve lash. but I only have two screws to adjust the carb. One is the idle speed screw, the other is the air fuel mixture screw. Can I adjust these two items on the stand? Also, what you attached refers to an air bleeder screw......which one if any of the adjustments I have on my carb. is this?
 

dylhainen

New member
So I can adjust Idle and air/mixture when the cart is on the stand as this has nothing to do with the throttle in my mind, correct?
 

dylhainen

New member
Absolutely you need to set the float height and drop -- it is not preset from the factory. There are several other minor mods. you can make that will help as well, but let's get this thing up and running properly first. :)

FWIW, this is why many racers choose to purchase a race-ready engine package...so they don't have to do much of the work themselves. Nothing wrong with either approach. You certainly save some money if you can assemble and tune the engine yourself rather than pay an engine builder to do that for you. The downside is that you will run into some snags in the early part of the learning curve that could cost you on race day, or by damaging your engine. The builders' assembly and tuning experience is often worth the extra money.

So I did float height, float drop, replaced throttle cable and ensured it was working as intended and adjusted the valve lash. What kind of other minor mods can I make that will help as well?
 
So I did float height, float drop, replaced throttle cable and ensured it was working as intended and adjusted the valve lash. What kind of other minor mods can I make that will help as well?
There's several other things that you "can" do. Are they necessary? Not at all.
Align the intake, level the carb, work with ignition timing, vary your valve lash, etc.
 

flattop1

Dawg 89
"The one without the spring"?
Whoops ! Item #13 is the idle speed screw .

Screenshot_20200921-100955_Google.jpg
 
^ Yep, and that spring had better be in there for tech. :)
The screw will vibrate right out if it's not.
We've seen the air bleed screw vibrate out while on the track if the spring wasn't long enough for as lean as we had it adjusted....just something to watch out for.
 
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