Runaway Black Widow

Justin4250

New member
Hi All! New to the forum.

I recently bought my son a used American Sportworks Black Widow 3171. It has a Predator 212 engine.
All was well until he started it in the driveway a few days ago and it took off on him. It drove into my garage, used the upside down wheelbarrow arms as a ramp to launch vertical up onto my toolbench! Thank goodness nobody was hurt but now I'm trying to figure out what happened. At first I thought the throttle cable or return spring were frozen because he was drifting around in the snow. I ordered a new cable and made sure that the throttle returned to idle properly. I told him next time we'll put the parking brake on to be sure. Well... while i was snowblowing yesterday he (without my knowledge) started it up and it took off again. I started looking into potential torque converter issues but thought I'd ask you all for advice. Currently the drive belt is slack. For the week leading up to the incident it unexpectedly stalled occasionally and when you tried to pull start it the wheels would try and turn. I pushed started it once or twice but looking back now I suspect that has something to do with my current issue. What is the most likely cause? Thanks in advance!

Justin
 

Attachments

  • IMG_1645 (1).jpg
    IMG_1645 (1).jpg
    38.9 KB · Views: 63

flattop1

Dawg 89
The clutch/torque converter is froze up or stuck some way.
Thaw well, then inspect thoroughly.
Disable or stress no use till corrected.
 

Justin4250

New member
I was just going to order a Comet 30 series replacement of the smaller driver but didn't know if I should replace the whole setup.
 

flattop1

Dawg 89
The one on the engine is the driver the one on the Jack shaft is the driven.
They should both open and close freely (realativley) .
A kill switch seems in order.
If you can push start it that's bad.
The driver will likely cure it.
Is the belt too small? Engine and wheels need to rotate easily , separately when it's not running.
 

Justin4250

New member
The belt seems to be the right size. It worked fine for a few weeks. I don’t know if it was the cold or the mud that caused the issue. I ordered a whole new setup for the smaller drive part and a new green spring for the driven. I have a new belt to use. We have a kill switch on the steering column but that didn’t help much since it took off as soon as he pull started it. If the belt is slack now, I’m not understanding how it is taking off immediately after it’s started. Next start will be up on blocks so I can figure out what is going wrong.
 

sundog

Member
If the engine revs out and will not idle you could have a bad carb gasket or a crack in the plastic carb block making an air leak. Otherwise make sure your idle screw is backed out so the throttle will close.
 

Bob Evans

Grumpy Old Admin
Staff member
The belt seems to be the right size. It worked fine for a few weeks. I don’t know if it was the cold or the mud that caused the issue. I ordered a whole new setup for the smaller drive part and a new green spring for the driven. I have a new belt to use. We have a kill switch on the steering column but that didn’t help much since it took off as soon as he pull started it. If the belt is slack now, I’m not understanding how it is taking off immediately after it’s started. Next start will be up on blocks so I can figure out what is going wrong.
There should be a free turning bushing on the inner part that turns with the output shaft of the motor. The belt should be riding on this bushing when the pulley sides are spread out and the motor is idling.
Make sure this bushing is rotating free and not damaged. If I recall, they're not expensive

BMI should have any parts you might need https://www.bmikarts.com
 

Justin4250

New member
Any recommendation for getting the 10mm bolt out to remove the drive? It turns freely when use a wrench. In the videos I’ve watched guys are removing it with an air impact wrench and the drive drum doesn’t turn when they do it. Is there a way to lock it in place while I turn the bolt?
 

flattop1

Dawg 89
Not 100 % sure what your asking.
The bolt turns freely?
Or the bolt and clutch/ crank turn together?
If the bolt turns free it's either stripped or broken.
The other case use something to hold it. Like the belt and a long bar.
Put wrench on and whack it with a hammer. Counter clock.
Do you know how to find the compression stroke?
 

Justin4250

New member
Sorry I wasn’t clear. The bolt and crank turn together and bolt is damn tight. Thought maybe there was a trick to keeping the crank from turning while I break it loose. As for finding the compression stroke- no I don’t.
 

flattop1

Dawg 89
Pull the plug stick your finger in the hole. Pull the cord slow. When you feel it blow air out it's on compression. Stick a screwdriver in the plug hole turn it backwards till it goes down. Slowly by hand with the clutch.
Feed 3-4 ft of rope in the hole turn it back up by hand till it comes up tight . It should stop , if not you need more rope.
Then remove bolt.
Try it a couple times to get familiar with when it on compression and how the piston moves down . Easier then it sounds.
 

flattop1

Dawg 89
Hold the screwdriver by hand roll the clutch the piston will come up then go down . Rotate it cc to the top then cc more till it goes down.
Keep it at the top till you get the feel.
 
Top