My polaris trail boss used to run great and I never changed anything on it. But within the last week I was riding it and it started to hit the when I give it gas at about 1/4 of throttle, I have changed the seating on the needle valve but still didnt work please HELP

 

Have you tried to defeat the limiter by disconnecting the black wire?

 

Yes I have tried that and it still did the same thing

 

Then I'd check compression to see where you stand. If compression is at least 115-120 psi,then ground the plug to see if you have good spark. If you do,then still could a carb problem,air leak(intake manifold, base gasket,crank seals)or even a possible break down in the stator,cdi,or coil problem could be causing it to limit when it gets warm.Check these things out but a manual can help you even more. DOWNLOAD 1985-1995 Polaris ATV Repair Manual ALL MODELS - Download ...

 

On my 1988 Polaris Trail Boss 250 RE/S, I'm trying to figure out "no spark" problem. When I disconnect black CDI wire, I get spark, I'm fine with that, but than I can't stop an engine with left kill switch or ignition key. Is it normal? Is my rev. limiter bad for certain? Is there a way to test the rev. limiter?

 

Disconnect the black wire from the limiter first.No good way to test it,BUT they all eventually fail.I would leave it's black wire unplugged. If this doesn't help and you have to pull the black kill wire from the cdi to get spark,then could be several things. Left control switch emergency kill switch along with the ignition switch wires ties into the black wire from the cdi. You can try to trace wires for shorts from these two switches. On some I was able to narrow it down to either one,but on some I ended with with a faulty kill circuit in the cdi itself that was shorting ignition spark. Only way to fix that is to replace it.The 5 buck manual I listed above does have several electrical trouble shooting guides along with good wiring schematics that can help you narrow it down.

 

Thanks for the advice OPT. Here are my tests:
1. Disconnect black wire from rev limiter only - NO spark.
2. Disconnect black wire from rev limiter and from CDI box - YES spark.
3. Disconnect black wire from CDI box only - YES spark

Does this still indicates that rev limiter is bad?

 

No doesn't indicate the limiter is faulty,but as a rule they all eventually fail.I'd still leave it's black wire unplugged. Still sound like a short either in the ignition switch or its wiring,left control emergency kill wiring or the kill circuit in the cdi itself. I've had several customers that didn't want to replace the cdi when I narrowed it down to that ,but wanted to use the choke to kill them instead! Again check the wiring for shorts,ohm out the wiring on the key switch and emergency kill switch wiring also if you can't find any bare wires. This is where the manual comes in handy with the wiring schematic and trouble shooting guides. Better than throwing a new cdi or both switches at it and still have the same problem.Just a process of elimination. http://visit.tradebit.com/visit.php/...75/264162958/9

 

Finally! I figured it out! I started tracing wires according to wiring diagram and found that the CDI black wire was not connected correctly, once I corrected the wiring everything works! Thank you for help opt!

 

That will kill spark also when hooked up wrong.. Glad you found the problem.