Throttle sticking no matter what I do...

[Wolfslash16]

Well, I've loved my slayer and it's been great so far. Except for when the throttle sticks at about 1/4-2/4 throttle. When I start it, it idles just fine with out moving, but after I warm it up and do a WOT pass, it will stick and stay there untill the truck comes to a complete stop. It will also creep forward at 3-4 mph at idle after it warms up too. While it's moving at full speed and I let go of the throttle, it will rev down to idle, then go back up to half throttle and stay there. I've tried adjusting the idle speed screw so I have to hold it at half throttle just to start it and it will STILL continue to stick. I've checked the throttle linkage and the carb, and I even checked the engine while I had it apart. If I hold my slayer off the ground and let it get up to about 3/4 throttle and I let go off the throttle (I let it go back to netural) the servo will go back to idle, but the engine continues to rev up to half throttle even though the carb isn't moving AT ALL when this happens. I have no idea why the throttle is sticking, and I've tried everything. Why is it doing it? PLEASE HELP ME FIGURE OUT WHY THE THROTTLE IS STICKING!!! It is geting a little worse after every run, and it's starting to freak me out! PLEASE, I NEED HELP!!!

[Snook Man]

I didn’t think the clutch bell issue you had would solve your problem.

Remove the air filter and watch the slide valve when you operate the throttle to verify it returns to the 1mm or less gap and that it does not close any further when you apply the brake.

If the carb slide valve is returning to the idle gap immediately when you release the throttle trigger and the servo is not glitching causing the throttle valve to fluctuate, your problem is not an idle issue Per Se, but an engine that is running too lean/starving of fuel due to the tune or an air leak.

[fallonguy]

Can you post a picture maybe we can see something that might help.

[Wolfslash16]

Here are some pics I hope they help...This is with full brake on...This is with full open throttle..

[Double G]

The linkage/slide on the servo horn should be screwed right before the point where there is binding. So make sure that you can spin it freely. Secondly, the carb should not be set completely straight with the engine, it will need to be around 10° clockwise. This may also require a slight adjustment of the throttle arm too. With the engine off, pull the filter and then manually push the throttle open using the linkage and feel for any binding.
Also, is that a crack or just imperfection in the carb body under the HSN?

[Wolfslash16]

Ok, thanks, could someone post a pic showing how the carb angle should look? I'm not sure at what angle to move it to so a pic would be nice. Any pics on how everything like throttle linkages etc. should look would be nice too. Also, does anyone know how to look for air leaks without spraying my engine with chemicals? I really don't want to clean it all off when I'm done doing that. As for the crack under the hsn, I'll take a look at it when I get home. I'm in my computer tech class at school! LOL Gota love 9th grade!
Thanks for the help in advance! Keep the help coming guys!

[fallonguy]

Also look at the ground wire to the ez start it look like it might bind there.

[Wolfslash16]

Well, I found the problem. There was a HUGE crack in the carb body just under the hsn. When i found it i was like, . I least I know what the problem was. I'll try and post some pics tommorow because it's getting really late here and I need to go to bed...

[fallonguy]

Well, I found the problem. There was a HUGE crack in the carb body just under the hsn. When i found it i was like, . I least I know what the problem was. I'll try and post some pics tommorow because it's getting really late here and I need to go to bed...

Glad you were able to find what the problem was.

[Wolfslash16]

Opps double post sorry

[Wolfslash16]

I do have one question for you guys out there, while I had my engine apart looking for leaks, I was looking at the backplate part 5274 and at the "ports" on the top of it. I was wondering what these ports are for, and if I made them larger if it would increase power or somthing. I only want to mod those ports, because it never moves and it can't throw anything out of balance...

[Double G]

Well, I found the problem. There was a HUGE crack in the carb body just under the hsn. When i found it i was like, . I least I know what the problem was. I'll try and post some pics tommorow because it's getting really late here and I need to go to bed...

You found it? YOU FOUND IT? What about me? I pointed it out!


Get a new carb body, move everything from the old onto the new and while you are doing that you may as well spend a couple bucks more and get the carb rebuild kit (bunch of o-rings).

[Wolfslash16]

LOL Sorry Double G. YOU did find the crack in the carb body, but it was actually under the hsn on the other side, right next to the idle speed adjustment screw. Go figure... I already got a new carb body, now I just need to put it all back together again. When I was looking at the hsn threads, I saw when I tighted the hsn in all of the way, the crack got larger. Hmmmm... Maybe the factory put it in too tight? I know I didn't cause it because I never took the hsn out, so that means I didn't have to put it back in, so I couldn't have caused the crack... and I didn't find the crack until I went to put it back in. Who knows. I'm just afraid when I'm reasembling the new carb I might tighten the hsn in too tight and crack the carb body. Guess I'll just have to be carful...

[fallonguy]

I do have one question for you guys out there, while I had my engine apart looking for leaks, I was looking at the backplate part 5274 and at the "ports" on the top of it. I was wondering what these ports are for, and if I made them larger if it would increase power or somthing. I only want to mod those ports, because it never moves and it can't throw anything out of balance...

Are you talking about the notched on the top of the backplate? they're so the piston doesn't hit make sure when you put it back in the notches go up.

[Double G]

As for the cut-outs on the backplate, leave them be. The HSN needs to be snug on the carb, you'll know when to stop--it's just like anything else were a metal screw is going into a plastic component.