76 MC-5 250 exhaust pipe

[kevin k]

Has anyone tried to mount a GS style pipe on a MC-5 ?  I,m looking for a more woods friendly ( quiter) pipe that would provide more torque in lower rpm,s.  I,ve got what I thought was a GS style pipe but it does,nt fit .  Interference at cyl. head and angle into the cylinder are different.  I realize there are different exhaust flanges but even then it would,nt fit.  Thanks

[Chakka]

Kevin,

The problem is that the frames are different. A 76' MC-5 frame is the later GP style, while the 76 Cross Country frame looks almost identical to the 75 models. I'd look into the possibility of fitting a 77GS pipe.  Maybe somebody out there can chime in as I am not sure it will work.

Chris

[Dennis Jones]

The setup some of us are using is to mount a 79 or 80 pipe. Look under the thread (My next project) and you will see a picture of this setup. You will have to fabricate a new rear mount, change the exhaust flange, and sometimes Adjust the front mount. If your bike is a 250 or 400 you will also have to change the head or trim a couple of fins. It looks real clean and gives real good bottom end. The downside is these pipes are hard to find in good condition but I think they may be being reproduced.

Dennis Jones

[kevin k]

Dennis,  Thanks for the info.  Sounds like the 79-80 pipe is what i,m looking for. Anybody know if ACE or Circle F are making a pipe? Also If anyone has a 79-80 KTM pipe I,m interested.  On a side note--I could use a 72 Jackpiner fuel Tank also.  Does,nt have to be perfect, It,s for a race bike I,m building.

[tomale]

As I was reading this I immediatly thought of ACE. They do make MC5 pipes but I am unsure if they make a conversion pipe. What I am running on my MC5 bike is a Protopipe- Pipe it was hand made back in the day for me, I was just at the right place at the right time, because it cost me nothing, It does have more bottom end than the stock pipe. One of the other things that I did was to replace the stock carb with a Mikuni, boy did that really help. I may not have as much top end but I have lots of bottom end and mid range and it revs faster, which I think is a good thing, but I would not call it pipey...What I did with my pipe to make it woods legal is to add an aftermarket sparkarrestor I rode the bike in a enduro a few weeks back and it was sound test. It came back at 102 Decibles. not as quiet as I would like but not too bad either. Maybe Ace can make you one with just a stinger and then fit a more modern muffler with a built in sparkarrestor... I have though of doing that to my bike but I am trying to keep it just the way I rode it back when the bike was new....

Thom Green,Still crazy after all these years!
76' 250 MC5 (orginal owner)
75' GS400 (project bike)
72'sixday (project bike)

[454MRW]

Kevin,
I have 3 bikes at Circle F in Houston that Kevin is building pipes for with a possible date of August 14th for completion. They are
1) 1977 GS6 250
2) 1978 MC5 250
3) 1980 MC 250
I will also be bringing my 77 MC5 250 Project Drag Bike down for him to fit one of his pipes to it also when I travel doewn to pick up the others. All 4 bikes have the angled down exhaust flange and the 78-80 head with the fins designed for use with torque pipes, but I also took an earlier HareScrambler straight exhaust flange and the early style head when I initially took the bikes down for Kevin to build prototypes from for production and it is possibe that he can make something for the earlier design flange and head. Mike

Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Pentons-1980 KTM 250'S

[kevin k]

That,s what makes this group so Great ...  Just ask and instant help arrives.  Your replies most certainly removes hours of trial and error.  Now I,ve got several options and I,ll be contacting both ACE  and Circle F.  I,ll keep you guys posted on what I come up with.  Thanks Again   Kevin  Kline   AHRMA  #  761

[Larry Perkins]

All should not forget that just because someone makes a pipe that fits a bike doesn't mean the pipe makes power right for that bike.  There are pipes being made that have been fitted to bikes brought to the well known maker that perform poorly.  Pipes are the right combo of cone angle and length learned from much testing or a dyno not just the mounting brackets being in the right place.  Just a word to the wise.

Larry P

[JohnnyO]

I spent years looking for a exhuast pipe for my 1976 250 mc5.I found a used one from ACE Pipes.Andy at ACE Pipes can custom make a pipe for your bike as he has the jigs to make them                                                                                                                                                                                                                                         Johnny O