Big Gun or T-4???

Hi Dave,

Finding someone local that has cut his side panal is not a bad idea. Haven't cut it yet. Getting conflicting input is making me cautious. I just put the UNI Filter that has the plate that replaces the backfire screen in and plan on running it that way this weekend. I think it should flow a bit more air than the stocker. I know that the Edelbrock is the shizz but I have been happy with my stock carb so far. What I don't want to have are jetting issues (If it ain't broke, don't break it! :D). Anybody else out there that ported their side panal and run with the stock carb and cam??? :)

I have a Big Gun. Pipe only. Where pipe connects to header is too big. I sliced it about a half inch and had to use a car muffler clamp to torque it down for a tight fit. All the rivets blow exhaust through them. But it sounds good and has good power. I bought the Race Series and got the silent core to bring it down to 94 db. They never responded to several e-mails. Bottom line, cool name (Big Gun) but thats about it. Oh, and the calender girls are cute.

I did the airbox cut-out this past weekend on my 650R and it definitely gave the pig some more juevos- seemingly everywhere throughout the RPM range. I wish I had done this sooner. I'm running the stock cam with a 175 main jet on the stock carb. I'm also running a year 2000 Big Gun complete system- no rivets, allen screws instead and a UNI airfilter. Also, I ride out in Livermore, CA at Carnegie where I'm not sure what the altitude is- my guess would be between 500-1500ft. above sea level.


i have the big-gun race pipe on my bike, and i am just about to buy the quiet core, is it hard to fit in? do i just remove the end cap and push the quiet core in and put the end cap back? :)

when you put the quiet core on, did you notice some real power loss/gains?

thanx in advance :D

i'm right there with BigTom--my Big Gun Race leaked out of the rivets-and i had to buy a pipe expander to get the mid section to fit tightly with the rear piece. And that was when it was new!

I called Big Gun repeatedly and just got voicemail-never a call back.

The pipe lasted a season-but only with lots of maintenance. The finish faded after a very short time, and the thing looks like crap. Finally it blew the rivets right out--the can is now basically worthless.

I wont be buying another Big Gun... :)

anywone else know howto replace the race core with the quiet core :)

DwD, I'll help with what I can...but try to tell me what you are running into...if you haven't started I'll let you know what I ran into...

BUT to tell you first that I have an old version where I had Allen screws all the way around so I was able to take off the end and the canister...I haven't seen the style with rivits so I just assume they can be drilled out as any other and replaced with an equal size rivet and rivet gun.

Ok just to fill you in on what I ran into...Again I’m going by what I remember with mine.

1) First off if you’re buying a new inner might be a wise idea to replace the packing with new as well b/c new packing is more flexible and easier to install than trying to reinstall old and the old is probably disintegrated. I had new packing...if you DON'T if you could try this;

The new packing comes with a cardboard tube inside that is larger than the core so you just slide it in over the core then pull the tube out alone leaving the packing inside the canister on the core. So I was thinking if you want to keep your old packing if you could find a large enough tube that would fit over your core between it and the packing so when you slide the canister off you could leave it inside and then just reinstall it the opposite but I’ll warn you that your packing may be in pretty bad shape.

2) Remove the end cap and slide the canister off but make sure you decided what to do about packing before b/c if you are keeping old…it’d be a good idea to slide it off so it remains in the canister if possible. So now you should see just the core on the forward canister mount.

3) With just the core present;

a. hold new one up to it and make sure they sent you correct length before you do anything that’s not reversible

b. Measure length from the head pipe to end of core so you know how far to slide new core on.

4) My core was spot welded so I took a grinding disk and completely cut if off but I was replacing but if you want to keep the old core try to cut just the spot welds and leave as much of the core as you can and try to keep it original shape.

5) For the new core on mine I found it was same diameter as pipe and no widening to slide over mount

a. so what I did was cut short slits in it at about 4-5 places around it so it could be widened and slid over the head pipe. and took a exhaust clamp from an auto store (one that is small enough to fit inside the canister). Maybe a strong hose clamp that of quality metal to withstand the heat could be used. Torque that down so its secure but not distorting the shape of the head pipe

b. Or if you have an exhaust spanner you may be able to just widen it up enough to slide on.

c. And if you want you can spot weld the new on but the clamp is still working fine for me.

6) Measure the length from head pipe to end so you know its same length and make sure its put on straight.

7) If your using old packing try to slide the canister and it over the new core but don’t mount the canister yet b/c you want to make sure the packing is pushed down around the clamp or base so the core is completely enclosed. If you have new packing put it into the canister first then slide it over with the cardboard tube still in again make sure the packing is down around the base.

8) Double check everything if your using rivets b/c they are more trouble to redo. Then fasten the canister down

9) It may have been me but my new packing was a little longer so I just took something dull and pushed it into the canister but left enough so when I put the end plate on it was snug to assure complete covering.

10) B/c I was putting a different spark arrestor on as well I had to trim the outer end with some tin snips so it’d slide into it but you’ll have to play it by ear.

The over all process was quite straightforward and didn’t take much time (~30-45 min b/c of grinding) b/c I had the packing and everything handy but if I didn’t It’d have taken longer. The grinding could be done with a dremel with the right disk but it'd be asking alot from a hand file.

Again...this is what I ran into with my old style...I couldn't imagine it too much different unless it was welded on more and required cutting off and then griding welds smooth.

Well I hope this helped.


I know that these forums have been a huge help to me after being out of the bike scene for a few years but it's too bad that some people have nothing more informative to say than "BIG GUN SUX". A well versed opinion helps people out but a slanderous line like that doesn't do anyone any good. Last september I started work at Big Gun and have to say that if anyone cares more about customer service it's Mike Young. Some other pipe company's (who will remain nameless) don't have customer service. Some of you have found out firsthand. We here at Big gun try and do our best but I'm the only man devoted to doing warranty's, customer service, and product development. It's a full plate for anyone to handle and sometimes people fall through the cracks. More often than not though we retain happy customers that come away with good feelings about thier purchase and our customer service. We offer a six month warranty on all of our pipes and after that a 50% discount on a replacement piece no matter what happens. I also try and fix any problems that come in even after six months if it is a legitimate claim. For the money I believe you're getting the best product with the most versatility. All of our pipes come with spark arrestors, are ceramic coated, and are convertible from race to quiet mode in no more than ten minutes with our new Vortex insert. I know that you feel that I'm biased but to tell you the truth the Thunder Alley pipe I had on my YZF 426 was a work of art. Bob does excellent work and it really waked that bike up, I would even buy another one. Big Gun's philosophy with power is to make the smoothest most usable power possible so as to not wear you down with having to control a huge hit. It may seem that the bike is slow or whatever it may be but you're actually just not feeling a spot where the bike hits "powerband" as the whole RPM range will be more pumped. If any of you have any problems with your exhaust let me know and I'll try and alleviate the problem to the best of my ability's. :)

I have to chime in, I mean "thump" in. I have a Big Gun Race Series on my '01 and it is GREAT! I used the Big Gun for a skid plate down the street a while back and when I emailed them for help with a replacement part on the canister, they immediately responded. A fella named Jason responded immediately to many of my emails and questions. I was pleasantly suprised. I shipped it to Cali from KY and they stuck it in the mail a couple days later after repairs. Even after the stunt down the street and a damaged canister, no leaks or problems in the rides after that. I give it high marks. :)

All right... I'm in.

I too have an older BG Race series. And ya know... I think it's great. And I too had fitting problems. Well.. only at the header Y pipe to mid section. It was almost too tight. I too thought "hey... slit the pipe and hose clamp it." But how hokey is that. So I opted for Permatex... and it blew out! Too damn hot for even the heat stuff. Now... it just runs with a teeny tiny leak. Oh well!!

Performance wasn't a big deal... but I also wouldn't notice 5 horses more or less. I just ride the damn thing. Some poeple are so picky they could tell you if the knobbies had 1/5" or 30/64th of an inch of tread! I dunno... I just flog it and go!

But I do have a Barnums cam, Eddy QS carb, cut airbox...etc. Nice!

Johnny J

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