Couldn't find an answer with a quick search, so here's my question. If the bike is plated, do you still have to have a spark arrestor for the trails. Will the catalytic convertor be accepted as a spark arrestor?

 

I don't know if there's any legal correlation between the bike being plated and if it needs a spark arrestor or not, but I've always seen the spark arrestor being related to the rules and regulations of the place you are riding (e.g. BLM or motorsports park regulations, independent of if the bike is street legal or not). And even if the regulations for the place you're riding don;t require one, I would use one anyway based on the fire hazard level.

A catylitic converter is NOT the same as a spark arrestor - bikes can have neither, either, or both. The stock KLX250S has both - the converter is in the front of the muffler where the head pipe joins in, and the spark arrestor is at the end, just before the exhaust opening. (I don't think drilling the exhaust baffle compromises the spark arrestor capability, but I could be wrong.)

Hope this helps.

Mike

 

I know they are not the same, but I would think a catalytic converter would be far more effective at preventing any sparks to exit from the exhaust than just a spark arrestor. I am just wondering if the USFS sees it as an effective alternative to a spark arrestor. I've look briefly at their website and did not find any information. I am curious because licensed vehicles (4 wheels) are not required to have a spark arrestor on USFS land.

 

With a little searching - All OHVs are required to have a spark arrestor. Is the KLX 250s considered an OHV if it is street legal. I couldn't find any legal definition of an OHV.

 

Man, I'm talking to myself here and answering my own questions. Probably should've posted it in the offroad section.

Federal regulations "44 FR 34836, June 15, 1979" gives this as the definition of a spark arrestor:

(i) "Spark Arrester" is any device which traps
or destroys 80 percent or more of the exhaust
particles to which it is subjected.

I would assume a catalytic converter meets that requirement. I am thinking the allen bolt at the beginning of the muffler is where a particulate trap is.

And federal regulations "44 FR 34836, June 15, 1979" state this as the legal definition for ORV/OHV:

(a) Off-road vehicle means any motorized vehicle capable of, or designed for, travel on or immediately over land, water, or other natural terrain, excluding:

(1) Any nonamphibious registered motorboat;

(2) Any military, fire, emergency, or law enforcement vehicle while being used for emergency purposes;

(3) Any vehicle whose use is expressly authorized by the authorized officer, or otherwise officially approved;

(4) Vehicles in official use; and

(5) Any combat or combat support vehicle when used in times of national defense emergencies.

So according to federal regulations any vehicle has to have a spark arrestor to travel off road.

http://www.washingtonwatchdog.org/do....html#8340.0-5

 

I think it would depend on how the catalytic converter is designed, i have no idea what it looks like but i know what they look like for cars, i put a high flow cat on my blazer i had, and it was just a honeycomb that you could see through, so i would imagine that flames would be able to get through that. Spark arrestors are designed to stop, what sounds like 80% of flames or what ever comes out, a cat is not designed for that. so i would think you still need, at least by law a spark arrestor...

i was watching canadian motocross on speed the other day and a guy fell over around this one sharp bend with a huge rut... the bike fell on its left side, i think it was a yamaha, and right before he went to pick it up a 6"-8" flame came out of the muffler, and then after it went away another one like 4" came out.. i was surprised... i said to my self , "so thats what a spark arrestor is supposed to stop" lol

 

I dunno, are they supposed to stop 'flames?' I thought the were designed to stop particles which cause sparks.

 

well the big gun spark arrestor looks a hell of alot like the backfire screen on the intake... just a metal screen, where would particles come from? maybe the fiberglass muffler packing, but its not like hot coals come out of the exhaust pipe...

 

Good research vurtle. I learned something. Thanks. Moab?

Willum
TC
Wichita Falls, TX

 

Very true.

It just seems like most of the written material about spark arrestors talks about them stopping 'particles.' I'm sure that flames are definitely taken into consideration though.