silencer identification

[oilspot]

I found a procircuit platnium pipe for my 92' rmx250. I started looking at the silencer thats on the bike now and it's defanantly not stock.
First I need to figure out if this is stock (off of some differant bike) or if is a decent flowing aftermarket.
here a link to a pic
http://s88.photobucket.com/albums/k163/oilspot/?action=view&current=S4021895.jpg
http://s88.photobucket.com/albums/k163/oilspot/?action=view&current=S4021894.jpg
If it a decent flowing aftermarket I'll just leave it in place after repacking it. I just don't want "cork up" and nice new free flowing pipe.

 

[76GMC1500]

You will find out whether or not it is a decent flowing pipe when you repack it. Take a look inside, most aftermarket pipes use some sort of turbine core spark arrestor while the OEMS use baffles.

 

[oilspot]

When you say turbine core???? Like a twisted baffle system.
It doesn't have any forest safe type markings so I'm guessing it's not a spark aresting type silencer.

 

[TimberPig]

What does the writing on the side there say?

It looks like either an FMF or Pro Circuit silencer, or a stock RM 250 silencer. The 89-95 RM 250's were pretty close relatives to the RMX's, particuarly the 89-92 RM's. Either way, it's not a spark arrested silencer.

 

[76GMC1500]

How do you know it's not spark arrested? It appears to have the USFS Approval stamp on the bottom. As much writing is on there, however, I'll bet it's the OEM muffler.

By turbine core I do mean a twisted baffle system. You'll know it when you see it.

 

[TimberPig]

That's not an OEM RMX silencer. They were huge, painted black, ugly steel things, that made the bike gutless and nearly silent.

It could be a stock RM 250 silencer, which is not spark arrested.

It could also be from FMF or Pro Circuit, which could be a spark arrested model, but without disassembly or further info, there's no way to say for sure.

 

[oilspot]

I'll try to get it pulled apart today and get some pics up.

 

[oilspot]

Here's what I found.
http://s88.photobucket.com/albums/k163/oilspot/?action=view&current=S4021902.jpg
http://s88.photobucket.com/albums/k163/oilspot/?action=view&current=S4021903.jpg
http://s88.photobucket.com/albums/k163/oilspot/?action=view&current=S4021904.jpg

Pretty funky in there!!!
Doesn't look very restrictive to me, but then again this is the first time I've looked at the inside of a silencer.
Spark arresting?
Aftermarket?
Ok for a procircuit platnium?

 

[ZOMBIE666]

nope not spark arresting, looks like a stock rm250 silencer to me

 

[oilspot]

Just had to go to the yamaha dealership to get a new plug for my sons pw50. Was checking out a fmf shorty. Same cheese grater tube down the middle with room for packing around it. Everybody working said that all I need is some screen in the end of the silencer and that will pass as a spark arrestor.

 

[TimberPig]

Just had to go to the yamaha dealership to get a new plug for my sons pw50. Was checking out a fmf shorty. Same cheese grater tube down the middle with room for packing around it. Everybody working said that all I need is some screen in the end of the silencer and that will pass as a spark arrestor.

That is a typical straight through, non spark arrested silencer intended for motocross use.

Whoever told you that is wrong. If it isn't an approved spark arrestor (USFS stamped) you can get big fines or even the bike impounded if you're riding on public land. Could possibly even be responsible if you start a fire, which is huge money.

You need to either add a Sparky or Cobra spark arrestor tip, or buy a silencer that is spark arrested already. Adding some non-approved screen will get you in trouble, as it is the same as running it the way it is now.

 

[apb]

Timberpig is correct -- make sure you've got a usfs approved silencer or tip, unless you're going to stay on the track.

Timber, where you been? I think your the only other '90 RMX owner on this board.. Are you able to ride in b.c. this time of year? or is it snowmobiles only?

 

[oilspot]

That is a typical straight through, non spark arrested silencer intended for motocross use

Factory or aftermarket?
I'm looking into the spark arrestors. I plan to spend no time on a track. Mostly blm land.
I'd much rather be safe than get some huge fines!!!

 

[TimberPig]

Timberpig is correct -- make sure you've got a usfs approved silencer or tip, unless you're going to stay on the track.

Timber, where you been? I think your the only other '90 RMX owner on this board.. Are you able to ride in b.c. this time of year? or is it snowmobiles only?

I've been busy, haven't had much time to visit the forums lately.

By picking and choosing your riding spots, it can be done, although there's very few who do. You need studded/screwed tires to deal with the ice, and some warm clothes. Mostly it's sleds right now. Just the other day we were getting a Summit 700 Highmark (151" track) stuck in over 5 feet of snow. At lower elevations there's only 1-2 ft though. Down in Vancouver and other coastal areas you can usually ride year round, although the winters are wet. This year though they've been getting lots of snow and ice too.

 

[TimberPig]

Factory or aftermarket?
I'm looking into the spark arrestors. I plan to spend no time on a track. Mostly blm land.
I'd much rather be safe than get some huge fines!!!

I just double checked the parts microfiche to confirm my thoughts that it is a stock RM 250 silencer. The endcap didn't seem quite right at first, but the microfiche confirms it's stock from an RM. I seem to remember my 91 RM 125's stock silencer had all that warning BS stamped into the side like that as well, which aftermarket ones don't normally have.

If you're riding off the track, get the silencer or a tip to add to that silencer. The cost of a brand new FMF silencer is way less than the fines. Unfortunately Pro Circuit no longer makes one to fit the 89-92 RMX's, that is spark arrested, so that limits your options somewhat, unless you want a new Pro Circuit with a tip added on.

Your other option is to look for a used spark arrestor model. This may take a couple weeks, but they are out there.

 

[apb]

I've been busy, haven't had much time to visit the forums lately.

By picking and choosing your riding spots, it can be done, although there's very few who do. You need studded/screwed tires to deal with the ice, and some warm clothes. Mostly it's sleds right now. Just the other day we were getting a Summit 700 Highmark (151" track) stuck in over 5 feet of snow. At lower elevations there's only 1-2 ft though. Down in Vancouver and other coastal areas you can usually ride year round, although the winters are wet. This year though they've been getting lots of snow and ice too.

Wow, makes me appreciate the year round riding we have at these lower latitudes (well, as long as I'm not too high up in the sierras). If you get too much cabin fever up in snowland, you're always welcome to come to CA and get your riding fix! :ride:

 

[oilspot]

The procircut pipe is supposed to fit with the stock silencer. The stock pipe is working with this rm silencer (fit wise). So if I can figure out what year rm pipe this is I can probably order a spark arrestor made from a rm.
Now I'm back to cross referancing (spelling) part numbers for differant year rm's.
I also see that fmf make a universal turbinecore2. Of course they have no specs on the silencer (does that make no sense at all!). Has anybody used on of these units?


I really wish that I could find specs on differant silencers. I don't mind making some hanger brackets. I just don't want to end up with something that hangs off the bike at a 40 degree angle or something of the sorts.