Predator 301 High Idle

[tsimnami]

I could see part of the problem back in the 2 pictures of you showing how far the black plastic piece returns naturally and when forced.
Firstly: That is indeed the throttle mechanism that controls engine speed.
Secondly: The black plastic Phillips head screw you were turning is indeed the idle adjustment screw. If you backed it out all the way you'd see your low jet stuffed down into the hole that's usually covered up by the screw shank. That's how you replace it, you just pull it out and drop a new one in.
Thirdly: That piece you were showing the return on is supposed to naturally spring return until it's stopped by the tip of the idle screw. That's how the idle is adjusted, screw it in and it prevents the throttle from coming back any further, raising the idle speed. Back that sucker up.
Fourthly: What I saw in those pictures was that thin spring's straight section that hooks onto the throttle under your thumb is bent. All non-coiled parts of the springs should be perfectly straight. Bending that zigzag in it shortens it, prevents throttle from returning properly. It's part of how the governor regulates the throttle no matter how hard you floor it, and it does it with those delicate-looking little springs and such, so any change like bends will screw everything up.

In response to the fourth point, yep I screwed that spring up by accident when I was trying to adjust something. I bought a new one the other day but its still revving incredibly high. (First picture is old spring second is new exact part that was installed.

I've cranked the idle screw back pretty much all the way before, but it normally just results in the engine not wanting to run at all. Its also pretty perplexing that the idle speed got worse (3000-5000) without me even touching the screw. Nevertheless I will certainly try again to bring back the idle screw as far as I can.

The throttle looks like it is bouncing back open after you snap it closed. Forget about the black philips screw for a moment. Snug it up and leave it. Find the chrome screw with the spring around it and loosen it up until it no longer touches the spring barely. Start engine and see how it responds. It should not want to idle at all. Unless throttle is pressed. Then run screw back in slowly until idle is achieved. (Chrome with spring around it.)

Hmm, the only chrome screw with a spring I could find is the one in the picture, but I doubt that's the one you're talking about as that only control the max throttle rotation. If this is the case, whereabouts should I look for the screw you mentioned?

 

[tsimnami]

I just realized I attached zero pictures. lol my bad

 

[OPmini]

I just realized I attached zero pictures. lol my bad

See if you can take a video of starting the engine and manipulating this black part of the throttle while the engine is running so we can see what happens

 

[tsimnami]

View attachment 126629

See if you can take a video of starting the engine and manipulating this black part of the throttle while the engine is running so we can see what happens

Ok, will do. I have to wait for my new crank case gasket to come in first though

 

[Denny]

Is the 10 mm nut holding the levers loose enough? The chrome idle screw looks like it might be backed out too far and bouncing the blade open.

 

[madprofessor]

That's some funky pictures...............The end of your throttle cable's running wild, kind of wadded up. It must be secured so it doesn't touch a single thing through the whole motion of throttle travel. Speaking of..............What's the throttle cable hooked up to to pull on? Post a pic the way it's hooked up when running. Now,..................
Denny mentioned the 10mm nut holding levers...............Believe he's asking if the nut that the long chrome throttle hand lever swings on has been loosened enough (kind of floppy) to not hinder the spring's ability to fully retract it, no resistance when you let off throttle.
And, yes the chrome screw about 1.25" long with a spring slid onto it is the throttle limiting screw. The spring is to keep it from loosening via vibration no matter where you set it. It's only job is to stop the throttle from being pushed all the way open when the lever bumps into it. Exactly the opposite of the black idle screw, which limits how much you can let off the throttle. Back the throttle limiter screw out for your own daring self, but run it in some for your kids, so they can only get maybe half throttle before the screw's tip stops the throttle from going any further. Limits both acceleration and top speed. Final thought..............
You're seeing what's happening when you're bent over the engine and hand-manipulating the moving parts. I'm interested in knowing what's happening when all you're doing is pressing the gas pedal (with your foot, not your hand). Block up the rear end with wheels off ground so you can rev it like you drive it (foot) and see what it does. Got a spring somewhere to retract your gas pedal? Your throttle return spring PULLS on the lever, it doesn't have the ability to PUSH your throttle cable backwards through its conduit! That's a major cause of throttle hangups. Can have a good spring at engine, but cable doesn't want to PUSH backwards through the conduit.
Attaching pic showing a shiny chrome very strong spring I added to pull my linkage forward (returns gas pedal to zero). Everyone should have a spring like that added on somewhere!

 

[tsimnami]

That's some funky pictures...............The end of your throttle cable's running wild, kind of wadded up. It must be secured so it doesn't touch a single thing through the whole motion of throttle travel. Speaking of..............What's the throttle cable hooked up to to pull on? Post a pic the way it's hooked up when running. Now,..................
Denny mentioned the 10mm nut holding levers...............Believe he's asking if the nut that the long chrome throttle hand lever swings on has been loosened enough (kind of floppy) to not hinder the spring's ability to fully retract it, no resistance when you let off throttle.
And, yes the chrome screw about 1.25" long with a spring slid onto it is the throttle limiting screw. The spring is to keep it from loosening via vibration no matter where you set it. It's only job is to stop the throttle from being pushed all the way open when the lever bumps into it. Exactly the opposite of the black idle screw, which limits how much you can let off the throttle. Back the throttle limiter screw out for your own daring self, but run it in some for your kids, so they can only get maybe half throttle before the screw's tip stops the throttle from going any further. Limits both acceleration and top speed. Final thought..............
You're seeing what's happening when you're bent over the engine and hand-manipulating the moving parts. I'm interested in knowing what's happening when all you're doing is pressing the gas pedal (with your foot, not your hand). Block up the rear end with wheels off ground so you can rev it like you drive it (foot) and see what it does. Got a spring somewhere to retract your gas pedal? Your throttle return spring PULLS on the lever, it doesn't have the ability to PUSH your throttle cable backwards through its conduit! That's a major cause of throttle hangups. Can have a good spring at engine, but cable doesn't want to PUSH backwards through the conduit.
Attaching pic showing a shiny chrome very strong spring I added to pull my linkage forward (returns gas pedal to zero). Everyone should have a spring like that added on somewhere!

Engine is off the kart right now but let me see what I can do for you with some old pictures. I never changed the throttle setup since I bought it and never had a problemo with it till now. The pedal is spring loaded by a rod as you can see in the video I sent and I also attached a few pictures of how things were attached before it went wrong

da pedal

youtube.com

Is the 10 mm nut holding the levers loose enough? The chrome idle screw looks like it might be backed out too far and bouncing the blade open.

Yep, I checked that but and it’s plenty loose. Where’s this chrome screw you’re talking about?

 

[madprofessor]

"Chrome"-looking screw (maybe should say just silver-colored) with the spring on it, the throttle limiting screw, is only an inch away from your throttle cable connection. In pic it's unscrewed so far it's about to fall out. The long handle of the hand throttle arm is curved around it. If it were screwed halfway in, you'd see the foot of the hand throttle arm bump into the tip of it when you floorboard it, limiting how far the throttle will go.
I see the throttle rod return spring, that's excellent, all rods need that.

 

[madprofessor]

Got a better look at your throttle cable connection to engine, it's awful. The cable itself looks like just a loose piece of wire stuck through a hole in the "throttle plate"? whatever, it's looped around somehow, just completely slack, and it should have no slack in it. You'd have to pull on it a good bit before the throttle would even start to move.
Maybe worse than that is the misalignment. The cable itself has to dive down after it comes out of the conduit to get to the cable "connection", and that gets worse the further the throttle is pulled. The end of the conduit needs to be pointed straight at the connection, so the cable isn't dragging on the edge of the conduit. Pizz-poor spring return on that.

 

[tsimnami]

Got a better look at your throttle cable connection to engine, it's awful. The cable itself looks like just a loose piece of wire stuck through a hole in the "throttle plate"? whatever, it's looped around somehow, just completely slack, and it should have no slack in it. You'd have to pull on it a good bit before the throttle would even start to move.
Maybe worse than that is the misalignment. The cable itself has to dive down after it comes out of the conduit to get to the cable "connection", and that gets worse the further the throttle is pulled. The end of the conduit needs to be pointed straight at the connection, so the cable isn't dragging on the edge of the conduit. Pizz-poor spring return on that.

To be honest, that’s how I bought it and I guess I didn’t know any better to change it, I just assumed it was on there correctly. I’ll try to make a few adjustments to fix it, thanks for pointing it out because I wouldn’t have noticed it myself