Stock Silencer Mods

[Wheelie]

Recently I modified my airbox, stock air filter and spark arrestor end cap. To compensate, I moved the clip on the pilot needle down one notch and jetted up to a #155, overall it made an impressive difference.

Somebody told me that modifying the spark arrestor alone wouldn't make that much difference in exhaust flow, that the restriction is further up the silencer, and other mods had to be done to make the most of s/a mods.

What can I do to help the silencer flow better on top of what I've done? Thanks for your help.

[4punksdad]

http://home.earthlink.net/~gellett/silencer.htm

I cut my spark arrestor screen off and cut 99% of the rear plate out. I see a definate power increase & better sound without that much more noise. Gabe took it a step farther. Take a look at this link to his page.

[Wheelie]

Thanks for the link, he gutted the sh@t out of the pipe. Did you have to cut up the silencer to remove the rear plate? What jetting and needle settings are you running?

[RideRed04]

I did the mod, here is a pre-review (I'll send one into leo later). The first thing I did was to pull off the SA and drill some holes in the plate inside the scilencer. Next I took a 4 1/2" grinder and grinded off the weld and cut the scilencer off with a dremel. Then I cut the pipe inside with a hack saw. After it was apart I cut some more of the main pipe off with the dremel. I matched it up and am welding it back together now. I'll have a better review later (it will make more sence).

[4punksdad]

Originally posted by Wheelie
Thanks for the link, he gutted the sh@t out of the pipe. Did you have to cut up the silencer to remove the rear plate? What jetting and needle settings are you running?

to cut out the rear plate, I did the following.

#1 remove the end cap
#2 use an arc welder turned up as high as you can get it, with a small welding rod...........reach inside as if welding around the edges..........you will not be able to weld with the welder adjusted like this.............you will be cutting faster than a torch!
#3 after the end plate is removed (except for the piece around the existing 3/4" exhaust outlet) you will be able to see all the way through your silencer.
#4 replace the end cap

I also have modified my airbox lid.......as of now, I have not rejetted.

[Wheelie]

I think I will drill some holes or cut the entire rear plate out.

3punksdad---Just an idea, I think you will gain even more power if you jet up a few sizes. When you are WOT and let off do you get a backfire? Just a thought

[4punksdad]

Originally posted by Wheelie
I think I will drill some holes or cut the entire rear plate out.

3punksdad---Just an idea, I think you will gain even more power if you jet up a few sizes. When you are WOT and let off do you get a backfire? Just a thought

Wheelie,
I tried to drill holes in the rear plate. I got a few holes in it, but I wasted several drill bits & really gained nothing. That rear plate was hard as heck to drill through. As far as cutting the rear plate out 100%.........I wouldn't suggest it. If you remove your end cap & look in, you will see you have a 3/4" exhaust sticking through & welded to the rear plate. If you remove the whole rear plate, you will have this 3/4" pipe flopping around inside the silencer.

eventually I might rejet, but my bike runs great as it is. No backfiring, and no fouled plugs. It even starts better