When the throttle cable is properly adjusted, the switch kills power to the cdi box when you let go of the throttle and the throttle doesn't return to the idle position. In other words, it detects a stuck throttle situation and shuts the ignition off.

Mark

 

No, it doesn't shut the engine off, it returns the engine to idle speed

 

Thank you so all I need to do is adjust my throttle cable?

 

Have a look at this.

As long as the throttle lever is depressed, the contacts should be open. When released, they should be closed. Adjust throttle cable accordingly.

Mark

 

The switch in the throttle housing serves a different function depending on which model of ATV you have.

It may be referred to as an ETC (electronic throttle control) or a TSS (throttle safety switch) - it may be open on throttle lever release or closed on throttle release (all depends on the model and how it's wired).

Generally; if it's an ETC, it's closed upon throttle release and activates the Reverse Speed Limiter module lowering engine speed to propel the vehicle at approximately 7 mph. This is a safety feature so if the throttle is released and the cable fails to return to the proper idle position (throttle sticks open due to a faulty cable or carburetor), the engine speed it limited allowing the operator to hopefully limp home.

As a TSS, when the contacts close it connects the ignition to ground killing the engine, but on some models the contacts are closed at idle and open during acceleration. On those models, if the throttle cable breaks or sticks, the engine speed is reduced to idle and the operator may simply adjust the idle speed to exit the area and effect repairs later.

So - depending on the model, the wiring and installed components, the switch in the throttle housing may be an ETC or a TSS and may be utilized either in a normally open or normally closed state.

In the case of the vehicle that is the subject of this discussion, activation of the ETC reduces the engine speed to limit the vehicle speed to appx. 7 mph which is just a little above idle when the vehicle was new. With age the wear of the clutch and belt may reduce vehicle speed to zero while engine speed is limited to about 1500 to 2000 rpm.

 

That explains the mixed messages I've found on line. Mine is a 2019 450. I've had an engine light intermittently since it was new.
I've tried adjusting the throttle and thought that fixed it, but the light came back.
I put a piece of plastic between the points and that seems to have stopped the light. BTW, My points are closed at idle.
But it still bugs me that I got the engine light to begin with.
How can I verify 100% that the etc caused the light, and how do I track the source of the check engine light.
I'm assuming the light is triggered by something working in concert with the points.

 

The 2019 is EFI and the light is activated by the ECU - you will need to take it to a dealer and have them diagnose the problem with computer software. It may be a programming issue or as simple as your applying throttle and brake at the same time.

 

Thanks. I think someone else asked this, and I'll ask it again. Aside from eliminating the safety feature, why not just take the points out of the system?
And how would I do that?
Maybe just leave the plastic piece in the points? I'm not seeing any function issues stemming from separating those points

 

Interesting you mention throttle and brake at the same time. I do this frequently when approaching garage doors (while plowing) because the throttle on these things is so jumpy.
I don't want to smash people's garage doors

 

The TRS (throttle release system) switch sends a signal to the ECU as does the brake light, so when the ECU sees both an open throttle and brake signal, it gets confused and turns on the check engine light. Try unplugging the brake light wire from the brake pressure switch and it may prevent the CEL from being triggered.

 

Very interesting.
May I ask,, where are your getting this knowledge? Meaning, is it on a service manual, or experience?
I went to mechanic school in 1975, but due to disabling injuries, I haven't worked in 30 years. And even then it was not as a mechanic. Life took different turns.
Still I've always fixed my own stuff and many friends stuff.
I say this so you know I do understand most of what you say. And I'm capable of using what you tell me.
Manuals can't replace hands on, but they do help.
Perhaps I should get one, but is what your telling me in them, or are you working from experience?

 

All of the above.

I have run my own shop for over 40 years - started motorcycle racing when I was 15 - I'm 71 now and still racing (when the mood strikes me - I don't race to win, I just race to have fun) - I have a degree in electronics and hundreds of service manuals. Books are printed because you can't remember everything you hear, see or do. I don't need to remember the tightening sequence or the torque value (that's what books are for). I do not have a photographic memory, but I do have wonderful retention. I have studied science, was a whiz in math, can cook and sew. Grew up on a farm, can operate heavy machinery, spent 6 years in the Army, can make explosives, was trained as a sniper (they found out this farm boy could shoot), worked at General Electric as a lab technician, received machinists training, learned computer programming, have worked as a carpenter, electrician, concrete finisher, managed a Montgomery Ward store for 4 years, was maintenance supervisor in a steel siding roll-forming plant and some other things I don't recall immediately.

I have many years of experience working on ATV's and Polaris has given me the most experience as they are the most maintenance intensive and failure prone on the market. Even Chinese ATV's have a better reliability record than Polaris except the 50cc through 400cc Chinese made Polaris models (50, 90 and 110 manufactured by Dinli, Eton and currently Aeon - the 150, 200, 300 and 400cc Phoenix, Sawtooth and Hawkeye Kymco produced models). Polaris has been partnered with Japanese Robin engines, Austrian KTM and some unknown engine manufacturers. Can't get a water pump seal for a Predator 525? Just order the parts from KTM at half the price of Polaris and in many cases NLA from Polaris.

Anyway, I have a working knowledge of Polaris, Honda, Kawasaki, Suzuki, Yamaha, Triumph, BSA, Harley, Hodaka, Rokon, Laverda, Zundapp, BMW, Gillera, Benelli, Puch, AJS, Sachs, Montgomery Ward, Sears and Roebuck and the original Indian models. I am an authorized factory repair center for TaoTao, Coleman, Roketa, Genuine Scooter Company, Yardsport, Yerfdog, Motovox, Monster Moto, Baja, Americann Landmaster, Lance, Ice Bear, Razor, Coolster and numerous other Chinese produced products. It's what 40 years of being in the industry yields.

Basically it's 90% experience and the gift that I had to be able to teach myself.