Predator 212 with 30 series TC, rpms too high?

[Falken]

My son and I are putting a go kart together from scratch. We have the standard Predator 212 engine, and a 30 series TC installed.

When I start the engine, and the selector is on START, with no throttle applied, the engine idles and the TC doesn't activate. When I switch it to RUN, still with no throttle applied, the rpms are so high that the TC activates, and the go kart accelerates almost full out. I've tried adjusting the idle screw, but that doesn't seem to affect things much. Should I be looking at adjusting the governor somehow? Again, not even touching the accelerator/lever that would connect to the gas pedal. Just trying to put it on RUN mode and not have the torque converter engage full on. Maybe adjusting the TC somehow?

I don't have a lot of experience with this, just trying to build a safe go-kart with my son that isn't ready to tear across the lawn by just starting it, LOL

Thanks in advance for any help, and if this has already been posted to death previously, please just point me in the right direction!

 

[Hellion]

Show us the kart and the throttle linkage on the engine. It could quite literally be set to mid throttle by accident or because there's no slack in the throttle cable. The throttle lever on the engine must return to idle with the help of a throttle return spring, and releasing the gas pedal must also allow the pedal itself to spring back. When there's no foot pressure on the gas pedal, the throttle lever on the top of the engine should rest on the idle speed screw if that makes sense.

The START lever of course is the CHOKE and its only purpose is to enrichen the air-fuel mixture (more fuel, less air) for starting but it bogs the engine otherwise (if you run the engine on choke) and makes the engine sound sort of strangled and lumpy.

 

[Falken]

Show us the kart and the throttle linkage on the engine. It could quite literally be set to mid throttle by accident or because there's no slack in the throttle cable. The throttle lever on the engine must return to idle with the help of a throttle return spring, and releasing the gas pedal must also allow the pedal itself to spring back. When there's no foot pressure on the gas pedal, the throttle lever on the top of the engine should rest on the idle speed screw if that makes sense.

The START lever of course is the CHOKE and its only purpose is to enrichen the air-fuel mixture (more fuel, less air) for starting but it bogs the engine otherwise (if you run the engine on choke) and makes the engine sound sort of strangled and lumpy.

The throttle linkage returns to the beginning position. There is a spring on the pedal and also the cable that pulls out all the slack and returns both the pedal and the throttle lever to it's starting position.

CHOKE that's the word. Yes, moving the choke from START to RUN causes the torque converter to spin and the go-kart to take off across the yard (found this out the hard way, which is why I'm here, LOL)

Thank you for your help! I'll get a pic today and attach it.

 

[Hellion]

You do want a basic RPM where the engine, after starting it, will run at its lowest possible RPM and not stall. You do want to insure that it will stay running and settle into its idle after a cold start and not just immediately gas the ever-loving crap out of it.

This may take some trial and error to get it where you want it.

https://flowracers.com/blog/go-kart-takes-off-start/

 

[Falken]

You do want a basic RPM where the engine, after starting it, will run at its lowest possible RPM and not stall. You do want to insure that it will stay running and settle into its idle after a cold start and not just immediately gas the ever-loving crap out of it.

This may take some trial and error to get it where you want it.

https://flowracers.com/blog/go-kart-takes-off-start/

Thank you for the link. I read through it, and I'm going to adjust the idle screw some more, but do you think it could have something to do with the "Jetting"? Is there another adjustment to the carb beside the idle screw?

 

[palate board atv]

i had the same problem . i think some predators are set to run for water pumps or the like. go to some of the utube sites for ways to disable the governor. also remove the air box so you can see what is happening and have someone work the throttle pedal. you should be able to see the throttle stop/ adjustment screw. and the full open stop on the carb.and make sure the friction post on the throttle lever is loose enough to work freely.being old and weak i have to stnd beside the cart to start it . last week some of the linkage came off and the cart ran away. across a busy street jimped the curb ad ran through the neighbor's side yard and out into a hay field til it found a stump hole and stopped then continued to run and fried the belt . it went about 150 yards now when i start it its aimed toward a retaining wall..!!

 

[ezcome-ezgo]

Um. That's made of wood.

 

[Hellion]

Um. That's made of wood.

Man, nothing gets by you! You should go read his "tire pressure" thread.

Thank you for the link. I read through it, and I'm going to adjust the idle screw some more, but do you think it could have something to do with the "Jetting"? Is there another adjustment to the carb beside the idle screw?

Have you made any modifications to the engine?

 

[Denny]

Did you loosen the 10mm pivot nut 1/2-1 full turn?

 

[Whitetrashrocker]

Did you loosen the 10mm pivot nut 1/2-1 full turn?

This is what i was just gonna suggest.

 

[charvell34]

is your throttle cable too tight, length of your conduit outer shell of your throttle cable to long

 

[Falken]

Man, nothing gets by you! You should go read his "tire pressure" thread.



Have you made any modifications to the engine?

Throttle cable and torque converter are the only additions. Nothing else has been modified.

EDIT: Except the idle screw on the carb. I've backed that off to reduce the idle as much as possible, hoping to lower the rpms and not engage the drive pully on the TC.

 

[Falken]

is your throttle cable too tight, length of your conduit outer shell of your throttle cable to long

I'm not even using the throttle at the moment. Just the act of moving the choke from START to RUN causes the drive pully on the torque converter to engage.

 

[Falken]

Thank you all for your responses so far!

I have a video of the engine running that I'm going to try to post next, but here are the images.

The problem, I feel, is the torque converter. With zero throttle, even having the throttle cable fully disconnected and returned to stock - the drive pully on the TC will compress and tighten on the belt and start spinning the driven pully that is attached to the sprocket which drives the chain and the axle. The drive pully is stock, unused, and has both garter springs properly installed and the original springs and weights in it.

I have reduced the idle (screw on the carb) to the point that the engine just barely limps along on the START selection on the choke. The TC will idle just fine, so long as the choke remains at START. As soon as I move the selector for the choke from START to RUN, the TC immediately engages, squeezes the belt, and starts to drive the axle (And I don't mean it grips a LITTLE bit, it will full on take off with a passenger sitting at the wheel).

Thank you for your responses everyone!

 

[Falken]

https://drive.google.com/file/d/1_e0_T-4G_uXTuDMSNT54juH-lxF4VxOg/preview

A video of the engine in action. You can see the axle spin and the engine rev up when I switch the choke to RUN. I point at the throttle lever, showing that it is in the full back position.

Let me know if the video/link doesn't work and I'll try to upload it elsewhere.

Thanks again!

 

[Edwin Spangler]

Disregard if you saw what I wrote here earlier.

How does this look on yours?

 

[Falken]

Disregard if you saw what I wrote here earlier.

How does this look on yours?

This is all under the air cleaner / filter? I'll pull it this afternoon and grab a pic.

 

[Hellion]

https://drive.google.com/file/d/1_e0_T-4G_uXTuDMSNT54juH-lxF4VxOg/preview

A video of the engine in action. You can see the axle spin and the engine rev up when I switch the choke to RUN. I point at the throttle lever, showing that it is in the full back position.
...

Sounds like a vacuum leak then. That means extra air is bypassing the carburetor somewhere and making the engine race on its own. You must verify that the carburetor-to-intake manifold gasket is sealing properly and not defective, like with a gap or crack in it instead of it being completely flat and conformal (like it should be), and also ensure that the two nuts holding the air cleaner assembly (and the whole carburetor) onto the engine are snug and tight. The nuts may have been installed only finger-tight at the factory (hey it's China not Japan) or they may have backed-off from shipment vibrations (the slow freighter from China) or from just sitting there being started over and over again. This happens a lot with high vibration machinery--just a fact of life.

When you release the choke lever to the run position, you are leaning it out back to a normal air-fuel mixture (the way it should be) but with a vacuum leak already "in play", the choke was allowing it to run a lot better, essentially correcting the air-fuel mixture imbalance. In other words, ideally, the engine really shouldn't run at all on choke. It should START but not sit there and idle. Before the EPA era, most single cylinder industrial engines would start but not continue to run on choke and you had to be quick to turn off the choke before the engine died....

.....
Nowadays with the Green Earth whackos in charge, most carburetors are set to run very lean from the factory and so they will run with the choke turned on. They won't accelerate or make any power, but they will sit there and go chuggeta-chuggeta happily along belching out black smoke for quite some time. Strange Days.

 

[Edwin Spangler]

This is all under the air cleaner / filter? I'll pull it this afternoon and grab a pic.

Yes. Should just be two 10mils.


Is this a brand new engine? Any chance of an exchange because you should be able to put it on the kart (or whatever equipment) and not have to worry about this. Shouldnt have to buy an engine and troubleshoot it before using.

 

[Hellion]

An (unrelated) quick tip:

Remove the three screws holding the recoil starter assembly onto the engine. Remove the recoil starter and "clock it" to where the T-handle is pointing to the rear of the kart (instead of to the back of the seat). I think 9 or 10 o'clock is the position but the screw holes will only allow a few options. Re-install the recoil starter, line up the holes, install the screws and voilà.

This permits you to pull the starter rope at an ideal angle and prevents chafing the rope with that hairpin turn you're making it do. It also puts you or your hands conveniently at the rear of the engine where all the rest of the controls are instead of reaching around all strange-like. This means the way-cool "212cc" decal in the center will be upside down but it'll be cool. All of ours are, and we're cool.