250-500cc Spark Arrestor

I did some searching and only found some discussions about full aftermarket silencers with Spark arrestors built in them. I am not looking for performance upgrades, just want to make sure I am legal to ride in a US forest I am planning on this summer. The stock silencer is not stamped so I am guessing it is not legal (correct me if I am wrong). I see in RockyM. that they have the bolt on spark arrestor tips but of course dont list my bike. Anyone know of one that fits a 2011 WR250? I am a machinist so modifying one is possible.

the OEM is USFS approved on most models, if it is you will find this written on it
typically you can look for an odd looking end as in not smooth
if memory serves me correctly 1992 to 2014 250-360 (Italian) Husks use the same basic one
by the way two strokes don't create sparks or flames that is the fault of four strokes, but as a typical govt. agency they cater to idiots and would need to teach them the difference which aint gonna happen

My 09 WR250 was stamped in the housing

I have the stock one off mine i'm pretty sure is stamped you can have.

Oh so very wrong !! I even had one on fire inside on a old TS 100 spitting red hot embers everywhere.

https://www.youtube.com/watch?feature=player_detailpage&v=spmFeh_kY2g


View: https://www.youtube.com/watch?v=T-Ddv6vc5mo


And I bet there is many more if you care to search

hmm, ya I don't suppose you ride around with a torch or lighter attached to the exhaust or do you? Obviously there's unburnt fuel and oil exiting the exhaust as a vapor. Won't ignite under normal conditions i.e., somebody not holding an open flame to exhaust outlet.

there is another link just above that one , no lighters involved and plenty of flames .

true but I believe that bike had some other issues so yes it's possible but most enthusiasts ride bikes in better tune than that. at least I do anyway.

Rather sad looking pile of $hite thats for sure but does show that a smoker can and will blow flames, Chances are slim but if you could only of seen that little TS spewing lumps of flameing carbon all around the streets you would of been mortified but laughed your head off at the same time as me and my brother were as I rung its poor little nuts off till all the carbon finally burnt away

i just looked all over it and it doesnt say anything about being US Forest Approved, or spark arrestor. It says it is EPA Noise compliant at 82 DBA but thats it. It is the stock one I bought it new. Last year at the National enduro in Indiana, at tech they did a sound check and it was 103 DBA which I had just repacked it 2 weeks earlier and the guy looked at it and said next year I will have to get a spark arrestor. I dont know.

Yeah I saw that and didnt think that was it. On other bikes (japanese) it said it on the side and actually said USFS approved. Thanks I never would have thought that was it. Save me some money, now I just need to figure out how to quiet it down.

how did it look when you repacked it? what did you pack it with? over 100 decibel is pretty loud

It was FMF packing. It was noticeably quieter than before I did it. It just seemed like when new it was loud compared to other European enduro bikes. I had a YZ250 that I bought a FMF Q for and it didnt seem at all to be any quieter. So I got a KTM silencer, the ones that look like a hockey stick, and modified it to fit. Real quiet. Loss some power but for riding around my house it was nice. I am going to get it out and see what I can do with it.

It will be stamped on the aluminum housing behind the side plate

I took off the side plate and it doesnt have it stamped. I went to the US forest website and found the chart with the info showing that Magnum Krizman KS650-A is the approved stamp. Like you said I have always seen it on the side though. Thanks for all the replys. Always get an answer.

That's good to know, mine doesn't have the end cap stamped but does have the aluminum housing stamped. I bought an FMF Q-Stealth for noise reduction and have my stocker for a back-up.

I didn't know that was what the stamp # was. I made a copy of the page in the manual explaining it has a spark arrester and keep it in my fanny pack.

Yeah I dont know how they would be able to look that up in the field but on the website it explains how to do a field test with a flashlight and other ways. I guess if you had a smart phone with you you could show them. Never had been checked except last year at the National enduro. Even then I dont think they were stopping people. The guy next to me had a bone stock YZ250 and he got approved.