Does anyone have any recommedation regarding how to approach this problem. Apparently no after market company currently sells a spark arrestor for the "01 KTM LC 50. I live in California and we have some strict laws regarding this.
I was think to maybe purchase a KTM 65 spark arrestor and have a welder create a new stinger (neck) as it comes from the pipe to the silencer with the same length and bend as the stock silencer on the bike currently.
Please help if you havbe done other things or can see a possible option here.
For anything but high level racing, I allways recommend that minibikes just stick a Briggs & Stratton muffler on the outlet of the stock silencer. Really, it works great. The B&S muffler that is shaped roughly like a pop can and has the inlet and outlet inline includes a USFS approved spark arrestor and it only costs about $6 at Home Depot. Just work up a bracket from whatever and maybe you have to make a sleeve to fit the pipes together.
Cheap, legal and effective. The only thing missing is snob appeal.
I would be willing to look into making you a spark arrestor if given the dimensions of the silencer. We have been making XR inserts with the USFS approved screen, it was very expensive to buy a roll of it, but it is what they specify.
What's your feel for a mass production of these? Are there lots of dads out there looking for this type of thing?
We would probably go steel to save on cost, but if it must be pretty it could be plated or painted.
I could never find one off-the shelf form my son'd KTM 50 pro-junior either. I talked to several dealers with no good answers. In the end, I made my own out of some screen mesh and pipe fittings. It works OK, but is doesn't have the formal USFS approved stamp on it so I am always afraid of being checked by the Ranger. It think there is a good market for a USFS approved one. I'll look for the Briggs and Straton SA in the meantime.
If you have the proper dimension screen, then you have a USFS approved spark arrestor. You will simply need to carry the USFS statute in your fanny pack so you can show the bozo who checks you.
I do think there is a pretty good market for a product such as this, and I am a little suprised that the big exhaust companies have not come out with this product yet. The 50cc spark arrester market is wide open as there are really no producers for any of the major companies making 2 stroke mini-racers.
I appricate the imput. What deminsions would be need to fabracate a similar pipe that would comply. Be specific, so that I can get exactly what would be needed. I have a number of others dad's who we race and ride with that would be interested int he same or similar product for the KTM LC 50, Cobra, Polini, etc.
In addition, does anybody know that USFS section that governs spark arrestors in National Forrests or California State OHV parks.
You can find the code in the thick California OHV riding area guide sold by the state. It is also on the internet but I'm not sure where....maybe the DMV site. I believe it says the screen must not pass anything bigger that 0.032 " in diameter. McMaster Carr sells small mesh stainless steel suitable for the task in small sheets.
Does your current silencer have a small diameter stinger on the end. www.hebousa.com sells a clamp on spark arrestor for trials bikes that may fit. It has the USFS ID.
I like the trials bike s/a idea. It may still be too big, but you may be able to make it work with some minor fab work.
To build one, I would need to know if what the shape of the silencer is (rectangle, round), and what the outside diameter is, or outside dimensions. To make it look right, I would need to know if it goes straight out the back, or if it is modeled like the big bikes and points up at an angle with a little snout that shoots back.
The KTM LC 50 has the same silencer design as the big bikes. It is a round cylinder with a bolt on end cone. There are no little pipes that stick out or anything. You can remove the 2 end bolts and expose the guts of the silencer. I will measure the diameter tonight of the silencer itself.
In addition, it does no come straight of the back of the bike paralel to the fender or ground. it follows the same angle up as the neck of the silencer coming out of the exhaust pipe. There is a clear angle to the silencer.
PWDAD, send me your silencer dimensions. I'll make one (hopefully soon, I'm also rebuilding a diesel engine), and send it to you. You just pay the shipping and it's yours.
Special deal for you only. If it is satisfactory, we can discuss more for others.