Converting a Silencer to Spark Arrestor ?

Got questions? We got answers....
Post Reply
User avatar
jc7622
Supporting Member II
Supporting Member II
Posts: 677
Joined: 01:53 pm Apr 24 2007
Country:
Location: Oklahoma

Converting a Silencer to Spark Arrestor ?

Post by jc7622 »

I came across a good deal on a used Pro Circuit Power Core silencer - $15. I assume it is a Power Core. The owner said it was a Pro Circuit and the only markings on it are "7-202" whatever that means.

It is not a spark arrestor version. Is the only difference between a spark arrested version and otherwise a little screen in the end cap? If so, if I added a screen would this make my new silencer "spark arrested"?
User avatar
Indawoods
Creator and Founder
Creator and Founder
Posts: 9951
Joined: 09:59 am Jun 12 2003
Country:
Location: Midwest

Post by Indawoods »

That's a great question for your local forrestry service! :wink:
*** Administrator //***
****'95 KDX 200/****

"People ate cows a thousand years ago for the same reason we eat them now. Cause they are easy to catch.We're not savages,we're just lazy. A cheetah could taste like chocolate heroin. But will never know. Those bastards are fast!!! "
User avatar
MXOldtimer
Member
Posts: 575
Joined: 05:03 pm Jul 15 2006
Country:
Location: Pacific NorthWET, Oregon

Post by MXOldtimer »

SORRY, It must have a forestry approved stamp on it or it's illegal. At least around here it needs the stamp.


.
User avatar
jc7622
Supporting Member II
Supporting Member II
Posts: 677
Joined: 01:53 pm Apr 24 2007
Country:
Location: Oklahoma

Post by jc7622 »

I did just discovered that it isn't a Pro Circuit pipe but instead is an FMF Power Core II. I guess the owner was wrong about the brand. I hope he was correct whe he said that it is for a KDX. Sheesh!

Does anyone have any experience with the Power Core II? How loud will it be? I'm not really into loud pipes. My buddies on 4T's say that they can't even hear me when I am right behind them. It really startles them when I pass them on the trail because they are used to HEARING people come up behind them.
User avatar
jc7622
Supporting Member II
Supporting Member II
Posts: 677
Joined: 01:53 pm Apr 24 2007
Country:
Location: Oklahoma

Post by jc7622 »

Here is a link regarding bikes, pipes, silencers and decibels. It is the results of a test done by the state of CA. Click on the brand and then scroll down and find a particular model. It appears they tested various riders and logged their make, model, pipe, silencer and noise level. Pretty interesting.

http://www.ohv.parks.ca.gov/?page_id=23038
User avatar
Jeb
Gold Member
Gold Member
Posts: 1894
Joined: 08:01 pm Jul 14 2006
Country:
Location: Cincinnati / Northern Kentucky

Post by Jeb »

Do a websearch for "Cobra Sparky" spark arrestor - it's a USFS-approved spark arrestor that you fit on the end of your current non-S/A type silencer. If for whatever reason you end up with a non-spark arrestor silencer like the Powercore you can add the Sparky. About $60, so the "cost-effective" $15 Powercore becomes less cost-effective.

A different approach would be to keep a lookout for an FMF Turbincore S/A or the Pro Circuit Type 296. Either are "forest-friendly".

Noise? I've got the PC Type 296 and it is a little bit noisier . . .

if you don't already know this, the way decibel measurement works is that a 3 dB increase is a DOUBLING of the power (barely noticeable) whereas a 10 dB increase in a DOUBLING of the noise level (definately noticeable). For example, 91 dB is twice as "loud" as 81 dB. That's not intuitive so I thought I'd mention it. Here's a neat read about this:

Decibels are designed for talking about numbers of greatly different magnitude, such as 23 vs. 4,700,000,000,000. With such vast differences between the numbers, the most difficult problem is getting the number of zeros right. We could use scientific notation, but a comparison between 2.3 X 10 and 4.7 X 10 to the 12th is still awkward. For convenience, we find the RATIO between the two numbers and convert that into a logarithm. This gives a number like 11.3. As long as we are going for simplicity, we might as well get rid of the decimal, so we multiply the number times ten. If we measured one value as 23 hp and another as 4.7 trillon hp, we say that one is 113dB greater than the other.

The usefulness of all this becomes becomes apparent when we think about how the ear perceives loudness. First of all, the ear is very sensitive. The softest audible sound has a power of about 0.000000000001 watt/sq. meter and the threshold of pain is around 1 watt/sq. meter, giving a total range of 120dB. In the second place, our judgment of relative levels of loudness is somewhat logarithmic. If a sound has 10 times the power of a reference (10dB) we hear it as twice as loud. If we merely double the power (3dB), the difference will be just noticeable.
"No farmer ever plowed a field by turning it over in his mind" -George E. Woodbury

CLICK FOR PICS!
User avatar
kdxquebec
Supporting Member II
Supporting Member II
Posts: 1255
Joined: 07:18 am Nov 24 2004
Country:
Location: Québec:North Pole
Contact:

Post by kdxquebec »

>|<>QBB<
jc7622 wrote:I did just discovered that it isn't a Pro Circuit pipe but instead is an FMF Power Core II. I guess the owner was wrong about the brand.
How did you do to confirm what brand the silencer is?

>QBB< ....
'89 KDX 198cc '03 Gasgas Ec250 '13 Husaberg Te300
*CANADA* LEADING THE WORLD IN BEING JUST NORTH OF THE UNITED STATES.
Image
User avatar
jc7622
Supporting Member II
Supporting Member II
Posts: 677
Joined: 01:53 pm Apr 24 2007
Country:
Location: Oklahoma

Post by jc7622 »

I confirmed the brand because it has '7-202' stamped on the hanger. I did some googleing and found out that part number belongs to FMF and not Pro Circuit. I have it all apart now cleaning and polishing it and it is definately not a S/A. The only thing it could be is an FMF Power Core.
User avatar
jc7622
Supporting Member II
Supporting Member II
Posts: 677
Joined: 01:53 pm Apr 24 2007
Country:
Location: Oklahoma

Post by jc7622 »

Hey, I just noticed you are from Quebec. The seller I bought it from is from Quebec. His first name is Pierre-Luc. Know him? I usually ask a lot of questions on an auction, but this time I didn't. Oh well.
plb
Member
Posts: 162
Joined: 07:59 am Aug 24 2007
Country:
Location: Québec, Canada

Post by plb »

Hi, it's me!!!

I bought a second bike for the spaire parts. I keep everything I need on (motor, rear wheel, etc) and sell the rest.

The shop where I bought the bike said it's a Pro-Circuit. I think it's true because check the end of the muffler, the FMF is straight and a Pro-Circuit is like a circle.
I usually ask a lot of questions on an auction, but this time I didn't.
For the muffler, he don't have any sticker on it and I'm not the original buyer... so I explained the story (about the shop who sold to me) at all the ebayer that wrote a question about the muffler to me and It's why I sold it at only 15$.

I have 100% positive feedback and what I sell, it's always in condition and very well describe (as best as I can).
I hope he was correct whe he said that it is for a KDX. Sheesh!
Yes it's from a KDX220 1999 and KDXQuebec have seen the entire bike before I disassemble in parts. It's one of my ride buddy :supz:

jc7622, well, maybe you can sell the pipe on ebay and you will receive a good price for. I'm sorry for you that the pipe isn't the model as you want, but I never wrote in the description about a spark arrestor. I think you can have a good sell price for, take this money and buy a s/a.

Or, do like us in Québec, keep the stock muffler because of the noise and the pollution (it's illegal here to ride without the stock muffler). It's why I sold it on ebay.
Last edited by plb on 01:32 pm Dec 19 2007, edited 1 time in total.
User avatar
jc7622
Supporting Member II
Supporting Member II
Posts: 677
Joined: 01:53 pm Apr 24 2007
Country:
Location: Oklahoma

Post by jc7622 »

Hey Pierre,

How's it going? I wondered if you might be on this board. I don't care if it is FMF or Pro Circuit. They're both built basically the same way with the same materials. I'm not going to complain over a $15 part.

I wire wheeled the stainless header pipe and got the rust pits off and then used a green scotch pad on the aluminum can followed by a polishing wheel on the whole thing. It looks pretty nice now.

Do you have ony other parts you are going to auction off?

JC
plb
Member
Posts: 162
Joined: 07:59 am Aug 24 2007
Country:
Location: Québec, Canada

Post by plb »

Hi John,

I sold a lot of the parts last month....

But, I will sell Race Tech 0,38kg springs soon (incredible upgrade!!!) and the stock fork with stock springs in too. My friend has the tools to put out the Race Tech springs out off the fork so he will do for me during the christmas holiday.

I put a KX125 front end on my KDX and the Race Tech springs and fork are mine (not from the «other 1999 bike of spare»... so I know the history off the parts and their real name LOL ;)

Pierre-Luc
User avatar
canyncarvr
Gold Member
Gold Member
Posts: 6943
Joined: 01:07 pm Nov 05 2004
Country: US
Location: The Mythical State of Jefferson

Post by canyncarvr »

Re: 'Is the only difference between a spark arrested version and otherwise a little screen in the end cap?'

No.

Take a spart arrester apart and you will not see a 'little screen'. The TEST to determine if you HAVE a spark arrester does involves sticking a rod down the hole to see if the rod runs into resistance within a particular length of rod. In MOST cases, that 'test' will get you through a tech at an event. Riders have been known to use such a thing (a little screen) to get past tech when they have no spark arrester. That bit of screen will provide the intended obstruction to the rod test AND burn up/blow out within a short period of time..and they are back to the superior (they think) performance of a non-arrested bike.


Jeb wrote: ..a 3 dB increase is a DOUBLING of the power (barely noticeable)..
Barely noticeable to the human ear...but not to a device trying to amplify an input.

Consider you have a generic one-each 80W amplifier..cruising along at maybe 10 watts. Along comes a sound that you cannot even discern is particularly louder than what you've been listening to...and the amp tries to push out 100 watts, it will clip.

..which has nothing to do with pretty much everything.. :rolleyes:

Wanna know more?

!Clicky!

Consider the source
Using a perceived level of knowledge to boost my self worth.
Non impediti ratione cogitationis

bike profile: !clicky!
User avatar
jc7622
Supporting Member II
Supporting Member II
Posts: 677
Joined: 01:53 pm Apr 24 2007
Country:
Location: Oklahoma

Post by jc7622 »

I am sometimes wrong (most of the time according to my wife) but don't some spark arrestors rely on strictly a screen? And then there are the ones that are more complicated like the FMF version, right? The ones below rely on just a screen as I understand it.

http://www.promotobillet.com/catalog/pr ... cts_id/248

http://www.promotobillet.com/catalog/pr ... ucts_id/48

And how in the world do these things quiet an exhaust down?

http://www.promotobillet.com/catalog/pr ... ucts_id/51
User avatar
jc7622
Supporting Member II
Supporting Member II
Posts: 677
Joined: 01:53 pm Apr 24 2007
Country:
Location: Oklahoma

Post by jc7622 »

Read this article. I guess it is getting pretty strict some places.

http://dirtbike.off-road.com/dirtbike/a ... ?id=332400

Here is another screen type SA. Quite unusual how it just mount on the outside.

http://spanishflyracing.com/parts.html
User avatar
canyncarvr
Gold Member
Gold Member
Posts: 6943
Joined: 01:07 pm Nov 05 2004
Country: US
Location: The Mythical State of Jefferson

Post by canyncarvr »

The question: 'Is the only difference between a spark arrested version and otherwise...'


was in reference to ProCircuit..and that is NOT the only difference in that case.

No, I did NOT know a simple screen came in a USDA approved/engraved/stamped version. While such would pass the rod test, in places where the stamp is also required..passing the rod test with the install of a screen of your own design wouldn't work.

The above link (dirtbike) is surely the way things are going. That's what you get with the Nazi type Big Government we have today in this country. Certainly it's a complete load of horsecrap..so?

One riding area locally is now being 'enforced' by BLM..with my money of course. One phallically challenged dickwad BLM hotrod has told riders he will 'knock 'em off their bikes, run over them' if there is a problem. At a recent event, I asked him what part of that sort of activity fit into BLMs enforcement plan. He said, 'I am law enforcement'.

When I asked him, 'What kind of excuse or reason is that?' I was told:
BLM DickWad wrote:YOU NEED TO LEAVE MY PRESENCE.
His nose was about 12" from mine at that point.

I stared at him..took a swig of coffee (yes...enforced with listerine!!)..didn't do as he requested.

He repeated hisself. I guess he figgered I was as hard of hearing as I was ugly.

Ha! I didn't hear him THAT time, either!! :shock:

The point is, if you don't want to run afoul of the Big Government Nazis, play it as safe as you can legal-wise. Might still have a problem with a little richard, but chances are maybe less.

Consider the source
Using a perceived level of knowledge to boost my self worth.
Non impediti ratione cogitationis

bike profile: !clicky!
User avatar
jc7622
Supporting Member II
Supporting Member II
Posts: 677
Joined: 01:53 pm Apr 24 2007
Country:
Location: Oklahoma

Post by jc7622 »

CC,

Your written words are quite witty. I can only assume your verbal communication skills are just as sharp and entertaining. I'll bet you pissed him off. How did the story end? I just hate guys like that.

We had a game warden in my county once that was like that. He was quick to pull his gun and threaten people. He pulled a gun on me once. We weren't hunting nor did we have any firearms - it wasn't hunting season - middle of summer. We were just out four-wheeling in my old Landcruiser in the river bottoms on private property. He made the mistake of harrassing the local senator's son who was just out doing some plowing in one of their tractors. The he picked on the senator's other son for no reason. He was at a gym working out. The game warden just walked in and started messing with people. That was the straw that broke the camel's back and got him fired. He then landed a job with the US Fish and Wildlife Dept and was sent down to Lousiana. We hoped those coonasses down there would string him up. Maybe they did. His name was Jerry Monroe. Luckily dirt bikes are pretty much under the radar her in OK - for now atleast. Most of the riding areas are privately owned thankfully. In comparison to the western US, nearly all land in the eastern states is in private hands. The BLM, Forest Service, etc are pretty much non-existent here, relatively speaking.
User avatar
canyncarvr
Gold Member
Gold Member
Posts: 6943
Joined: 01:07 pm Nov 05 2004
Country: US
Location: The Mythical State of Jefferson

Post by canyncarvr »

I can't help being quite whitty..I'm caucasian..

There was a second LEO (term used loosely..this was BLM, not USFS) standing a few paces away. Evidently he sensed something was going on. Little richard certainly had his back up. After the second iteration of dorkwad telling me to remove myself from His Presence, the second Kop sidled toward us, from the rear/off to the side. Mr. **** saw him. He immediately turned into Mr. Nice Sweet Guy!

'I'm sorry,' he said. 'What was your question?'

I asked the same question using the same words..said in the same way that I did the first time, 'What part of....'.

He then proceeded to deny having ever said any such a thing, saying, 'That's not the way thiings are done...', etc. etc.

THEN I went and got the guy he SAID the 'knock 'em off...' to, introduced HIM to the State Parks Rec guy that was there. They had an interesting dicussion about funding and such, who was whose boss, who to write to concerning flagrant ethical violations...stuff like that. :twisted:

Ha!


I love screwing with richards....pun intended. :butthead:

Consider the source
Using a perceived level of knowledge to boost my self worth.
Non impediti ratione cogitationis

bike profile: !clicky!
Post Reply