Homemade Silencer

[jcheatham]

Hello I have a 2000 YZ295 and LOVE IT! Before I sent off my head and cylinder I hade the SST pipe and Powercore 2 exhaust set up. Seeing that SST was the worst thing I could possibly have on with my EG295 I had to store it. I switched back over to my full stock set up since my fmf silencer had holes all around it from corrosion. Im going to try and make my own silencer and a carbon fiber tip since I have always wanted to see how carbon fiber is. Im currently going to school for machining so making brackets and such wont be a problem. My question is, does the actual diameter of the silencer make a difference, I know length does. Also the tube in the inside does the size of that matter and do the size of all those holes make a difference. I would like to get this to perform like stock and mabey better. I might have missed some things. any input will help me with my future project!

[kiwi86]

I would be quite interested in your results, if you google search Gordon Jennings 2 stroke tuners handbook you will come across a downloadable PDF file on all things to do with two stroke engines. That will have formulas for working out the dimensions for a silencer.

Keep us posted on your progress!

[BDubb106]

Im looking forward to your results as well! Should be interesting to see what the average guy can make with some off the shelf materials

[yamaha7442]

Everything will make a difference.

Length, diam, packing material, hole size

in the perforated inner core.

...small holes in the perf will be a lot

louder, as well.

Copy what you already have would be a

good place to start

...m4 exhaust makes an adjustable silencer with

different size tips for the outlet, and the

power can be shaped / makes a big difference

just by that little change, and will affect jetting /

heat in the pipe and motor.

...burnt out packing can also lose as much as

2 to 4 hp on a dyno run, depending on engine size, and also make the engine

run like crap, so keep it freshly packed

Edited February 7, 2013 by yamaha7442

[souliog]

I need to take a few pictures, but I was able to cut 4" off the stock silencer and make a shorty out of it. Works good on my 250.

[2 Stroke Boogie]

Whats a YZ295?

[jcheatham]

Whats a YZ295?

a YZ295 is a YZ250 bored out to a 295. Eric gorr is one of the best!

[BDubb106]

I need to take a few pictures, but I was able to cut 4" off the stock silencer and make a shorty out of it. Works good on my 250.

Not a stock silencer, but I broke my shorty and had this sparky laying around. Needless to say, it is no longer a sparky. Same concept though... I cut it down so it is now 6 inches long.

Edited February 7, 2013 by BDubb106

[jcheatham]

Not a stock silencer, but I broke my shorty and had this sparky laying around. Needless to say, it is no longer a sparky. Same concept though... I cut it down so it is now 6 inches long.

that looks pretty good mabey I should just buy a cheap silencer on eBay and just cut it down a bit. And then make some carbon fiber tips

[BDubb106]

that looks pretty good mabey I should just buy a cheap silencer on eBay and just cut it down a bit. And then make some carbon fiber tips

would probably be cheaper, and get you much closer to a well performing product than experimenting. Just keep in mind. The shorter the silencer the more bottom end, less top end.

I just use this for the more SX oriented tracks where you never get above mid throttle because the runs are so short so I dont need the over rev. Otherwise I use the off the shelf shorty, or standard silencer so you should def experiment with lengths. I usually find banged up silencers on ebay and cut/ weld them just to experiment. I have not paid over $10 for a silencer and I have a full shelf of them of all diff lengths. Most of which I have never used, but plan on playing with this summer.

[Chill_MotoX]

It would be cool and maybe easier if you can make a can and just have it so that can utilize the enduro engeneering spark arrestor end cap... Also seen lexx carbon fiber tips but not sure if it's for the 2 stroke...

[kiwi86]

Any more progress?

[Shhhh]

would probably be cheaper, and get you much closer to a well performing product than experimenting. Just keep in mind. The shorter the silencer the more bottom end, less top end.

I just use this for the more SX oriented tracks where you never get above mid throttle because the runs are so short so I dont need the over rev. Otherwise I use the off the shelf shorty, or standard silencer so you should def experiment with lengths. I usually find banged up silencers on ebay and cut/ weld them just to experiment. I have not paid over $10 for a silencer and I have a full shelf of them of all diff lengths. Most of which I have never used, but plan on playing with this summer.

Great idea! I might do this myself...

[jcheatham]

Any more progress?

not much unfortunitly. I've been looking around and thinking its not about length, but volume. I dont know if its true or not but it makes since. More volume the more top end and the quieter it will be.

[jcheatham]

Any more progress?

not much unfortunitly. I've been looking around and thinking its not about length, but volume. I dont know if its true or not but it makes since. More volume the more top end and the quieter it will be.

[kiwi86]

I read on another thread that a short silencer will increase bottom end. That kind of flies in the face of what I thought was the case with intake/exhaust tracts, that you make them long and skinny for bottom end, and short and fat for top end.

https://www.thumpertalk.com/topic/801589-my-modified-silencer/page__hl__+silencer%20+dimensions#entry8365640

Edited February 12, 2013 by kiwi86

[BDubb106]

I read on another thread that a short silencer will increase bottom end. That kind of flies in the face of what I thought was the case with intake/exhaust tracts, that you make them long and skinny for bottom end, and short and fat for top end.

http://www.thumperta...ns#entry8365640

yea, you have it backwards.