Bending Pipes to Fit 76' 125 KTM GS

[Chakka]

I just got my GS pipe back from the welder who filled some pin holes. After a bunch of trial and error I figured out the install procedure and had at it. I knew the pipe would need mods because it is def from a 77'GS, the mounting tab was to the frame down tube, not the usual spot on 76' models. I used a grinder to remove the mounting tab off an old Jackpine pipe that was shot and cut the incorrect tab off the new pipe. As I suspected the the Jackpiner piece fit like it was custom made, so far so good, so at least the front 50% of the pipe is identical on both 76 and 77 bikes. Then I went behind the bike and realised beyond the shock the pipe projects straight out at about a 10 deg angle. The tail end of the 77' is much wider....duh I should have known. It needs to be drawn into the bike approx 1.5" What do you guys recommend as a good way to bend this in towards the bike? Plenty of heat? Running down the center of this pipe  is the internal stinger piece that mates with the gigantic silancer. I don't want to damage that.

Chakka

[wolfmanonapenton]

Well" If I can't get the one I need im eventually going to find a ratty 1974-75 125-175 pipe with the center stud mount allthread center nut style with thetwo hole end cap and if the headpipes bent or junk ,I was going to cut it right on the center weld right around it with a ceramic air cutoff tool right above or about in the area above carb when it would be mounted on bike best way to do this is make your markings with chalk or paitmarker then,find a 76-77-0r if you really want to make it run find a newwer type 78-79-80type pipe and cut where you have measured the other pipe to be cut and try to match a place and measurment to cut the back of it off then put the headpipe on either style, figure where your mounts will need to be welded on the pipe and you may have to change the frame mounts if you go newwer than a 77headpipe!Al's shroud kits were perfect for thing for this fabricating project,if you could still get a 74-75 jackpiner shroud and end with the stud in the center,and a core kit and a packing kit,and one of his new 125-175 mc5 nos pipes that he had alot of them left last I checked?Cut the back off of it after mounting both pipes or trying to and making the needed markings again and matching and WALAHH!!!you have a pipe put together after, take both pieces and  mount your headpipe tab changes first, with on bike then hold back piece where it looks right, then mark take off, weld together paint with some gloss black and take endcap off before remounting as whole, might have to tilt carb, slide airbox over,take left engine strut off or shove top of it torwardsjug to make room to mount and should look really good!If you do it right it will look like a factory job?This is definetly what I will do if I never find a 76gs pipe,I will never alter or change an original as they are just to rare of pipe!125-175 are the same pipes ?The mc5 pipes that Al has you could use rear section for a trick end on a badly beat or rusted other Penton pipe to give it that motocrossie look!Or run the whole thing on it from Al, buy just changingthe mounting tabs and have a Gs with an Mc5 pipe,bet it will run better and crisper if you want to vintage race it? Better yet buy two from Al and keep one for race pipe and one for fabrication!Call Al and see what he has left GOODLUCK?!!Wolfman Ps.theres a lot of pistons out there for the early ktm 125 engines!:DHope I helped you?Happy Thanksgiving!