[Bobn]

I have a 1997 SLR650 and a 2000 FX650 "Vigor".
On the FX I removed the final baffle from the standard cans and increased the main jet to 175 (was 168 ), the difference was astounding.
I've just done the same to the SLR and the result is the same, the engine is more tractable, develops more torque (it'll pull from under 3000 RPM in top) and sounds fantastic.
I removed the baffles by drilling a series of holes around the little exit pipe, then used a cold chisel to join them up, then shoved a bar up the pipe and waggled it around for 5 minutes or so until the welds on the internal baffle broke and I was able to pull the exit pipe. Finally I cleaned up the hole with a small grinding stone.
I cannot emphasize enough what a transformation this has wrought, the standard bike just seems like a castrated sad thing in comparison....

The £1.75 is for the main jet BTW

 

[Bobn]

...if you're sceptical, I can offer you a test ride...........

 

[catteeclan]

Here's a domi cheat. The hole now is around 3 times the size and the end caps refitted.

Ripping the air box snorkle out give it a bit more too.

 

[Bobn]

Here is the silencer on the FX with the baffle tube taken out. The hole isn't as neat as I'd like because I had to chain drill around the baffle tube and join the holes with a cold chisel. I tidied the hole up as best I could with a grinding stone. I'm waiting to borrow a cone-cutter from a mate that will produce a perfectly round hole.
The difference in performance is remarkable and the sound is very nice. It passed the MOT like this.

 

[77rons]

Where did you buy the jet from?

 

[Bobn]

I got mine from Manhattan Motorcycles in Sheff, but he now tells me the ones I had were a special price because he'd had them in for ages and nobody ever buys 175 mains....

 

[chrisland]

hi mate did you do anything else to the carb ? like ajust the needle or anything or did you just fit the main jet ? ive just got a t reg slr650 and want abit more grunt
thanks chris

 

[Bobn]

No, just remove the baffles, put a 175 main jet in. This made sufficient extra power that I was able to go up to a 15T front sprocket too.

 

[chrisland]

nice one
i,ll get one bought and fit it and post back the results.
i,m going to go down a tooth on the front sprocket as well

 

[Bobn]

DOWN one tooth ????
You'll be redlining at 70MPH! Seriously, go UP to 15T, it makes the bike much better

 

[chrisland]

i dont want to be going 70mph i only use the bike in town and down afew lanes,it will never see a motorway, i would rather have more accelaration ,

 

[plugwit]

Here's a domi cheat. The hole now is around 3 times the size and the end caps refitted.

Ripping the air box snorkle out give it a bit more too.

how do i find this post
i can see the author and how many posts are attatched to the author but from this picture can i get to the original post.that would be really handy for all threads.i bet you can do it but i dont know how

 

[catteeclan]

Click on the little blue icon after "catteeclan"

 

[Bobn]

i dont want to be going 70mph i only use the bike in town and down afew lanes,it will never see a motorway, i would rather have more accelaration ,

Well it'll save you money on front tyres, shouldn't imagine the front wheel will spend much time on the road :toothy10:

 

[plugwit]

Here's a domi cheat. The hole now is around 3 times the size and the end caps refitted.

Ripping the air box snorkle out give it a bit more too.

so,all i have to do is drill a hole and put in a bigger main jet.surely cant be that easy.also,did you put the silver surround back on the end

 

[Bobn]

Yes it is that easy.
I'd go for the full baffle removal (like I did) rather than drilling one hole.

 

[catteeclan]

The hole ended up about 2 1/2 times as big in the end and yea I put the cap back on.

 

[plugwit]

The hole ended up about 2 1/2 times as big in the end and yea I put the cap back on.

21/2 times the size of the exhaust or 2 1/2 times the size of the hole in the picture,what size do you reckon the hole is?

 

[catteeclan]

Think I drilled another hole along side the first then filed them into one large hole. Drill bit was 12mm.

Got a Produro on now.

 

[plugwit]

Think I drilled another hole along side the first then filed them into one large hole. Drill bit was 12mm.

Got a Produro on now.

and my last question is,can you remember what size jet you put in.cheers for all your replys