Help!

Recently I purchased two 70 series Hensin Tierra's for my two boys. I need to slow the machines down. They have a throttle screw, which would be fine if they road around in circles on a perfectly flat track, but they don't, and the boys know how to operate a screw driver.

I need to find another method to control the speed. Does anyone have information about CVI speed limiters, exhaust restrictors, or other idea to achieve this.

The machines are in lockdown until we resolve this issue.

Thanks!

 

One idea..... Get a alllen head screw to replace the throttle screw. Then hide your allen wrenches! Maybe you can find some other odd head screw besides a allen head.

 

I was thinking the safety/security TORX screws. They require a special TORX driver to get them out. Fastest and cheapest way imo.

 

Set the throttle screw where you want it, if they decide to adjust the screw on their own, then the ATV's go away. Just a dad's opinion but if they can't abide by your rules then they aren't ready to ride ATV's anyway.

Jaybee

 

Jaybee, I agree 100%. My son is only one and too small to ride anything other than his Power Wheels quad, but I plan on taking the same approach with his first real ride. Disobey the rules and it's gone!

 

try a cdi box a predator 50,it has 2 settings and most cdi boxes are enterchangable.

 

I agree with setting the rules and making them obey or no riding. But some of the mini quads are just geared to high. If you limit the throttle too much they just can't make enough RPM's to get going. What you probable want to do is change the sprockets. Go with a smaller sprocket in the front and or a larger sprocket in the back. This will lower the top speed and give you much better low speed torque. This will let you back out the throttle limiter some and let the engine run higher RPM's, more in its power band, rather than lug around just above idle.

 

Thanks for all of the responses. You have identified the root of the problem, which has everything to do with performance, not parenting. Gearheads are gearheads from birth, and we've all broken, or should I say bent the rules a bit, regardless of what you're father told you when you were a kid.

There are many things that can be done with the screw, however I only included that statement in jest . I/C engines do not have a constant torque curve, which is why setting the screw in one position doesn't work.

What I really want is a speed limiter, but, after speaking with several vendors, all of whom are interested in increasing speed, have not found what I'm looking for. I haven't been able to get into the guts of the machine yet, but plan to change the sprockets to help mitigate the low end problem. Ultimately, I will probably end up building a control loop to achieve what I want, if I cannot find COTS items.

Here are some of the COTS items I'm looking for:

1. A speedometer with a 0 - 25 mph scale with an output relay that is activated at a set speed.
2. a 12V DC rev limiter that will interface with the existing CDI. The CDI is a 12V system, not a grouding system.

Regarding the CDI box on a predator 50; I haven't been able to find any info on that. I contacted the parts department of local Polaris dealer and they had never heard of a CDI box with two settings. Any additional information regarding that item is appreciated.

Thanks again

 

the cdi box has 2 screws on one end and you can loosen them and remove a small metal piece that conects the two. conected it has a lower speed off is faster. if your dealer doesnt know what one is find another dealer.

 

His doesnt have that it's a 4 stroke 70cc motor. They run very well.