So, here is my tale of putting a pipe on my 2000 Monster 900S.
I ordered a Ferracci full system 2 into 2 low pipe in December. But it didn't fit. Ferracci was nice, and would have let me return it, but I said NO WAY, I just want one that fits! They swapped the header for me, but the new one was about the same. Here was the problem: The rear header was too close to the swingarm by the chain, and the chain would hit the header and would eventually cut it. Here is a pic of the lack of clearance for the chain:
Note the melted plastic swingarm protector! This is because because of the angle of the pipe: as the swingarm rises, it gets CLOSER to the pipe. Thats why you see the plastic has melted in an arc matching the shape of the pipe, it hits! If you look very closely, you can see the scratches from the chain on the pipe in this shot:
This is a bigger problem than it looks like, because in not long, the chain WILL cut through that pipe, just like a chain saw. This isn't acceptable. There was also an issue under the swingarm where the crossmember would move up and contact the pipe as the swingarm moved up. Unfortunately, I couldn't get a good picture of this. But if you fit a pipe inspect carefully how the swingarm moves upward and check how the clearance closes between the swingarm crossbrace on the engine side and the pipe. (I'll note that these issues may not be a problem for Monsters with the steel swingarm, but 2 separate pipes from Ferracci had this problem on my bike. Also note that Sil is the original manufacturer, so this is probably an issue with their pipe too!) The main problem was that the rear header had much less bend in it that than stock one. See this comparison shot, with the stock pipe on the left:
So how to fix it? First, the pipe needed to be opened a bit: I needed just a little more length between the front header and the rear. I made this rig to stretch the darn thing:
Stainless steel is darn hard to bend. Even heating and then jumping on the 2x4 shown had little effect. It helped some, but not enough. Hmm. Time to cut:
I had the rear header pipe cut at the top and the bottom: Top cut:
Bottom cut:
Note we didn't cut the pipe completely apart. This let it hang together and helped us position it. With the cuts made, it was fairly easy to fit the pipe and then tack weld it in the proper position. Then it was removed and welded solidly back together. With the new bend, the pipe bend looks a lot like the stock pipe, no surprise there! Stock pipe on the right:
Clearance to the chain was solved:
But there still wasn't quite enough clearance underneath the bike, where the inside swingarm crossmember would come up and hit the pipe. The simple answer there was to ding the pipe to provide clearance:
Finally! Done and ridable! Hmm... I think Ferracci should give me a big discount on my next purchase! This was not an easy to fit pipe! But the pipe sounds great! I also put in the airbox kit and power commander. But way back in December, before any modifications, I did a couple 'stock' dyno runs. The "before" run is box stock. The "after" run is with the FbF Full 2 into 2 low system, Airbox cover removed and BMC filter, and power commander. Interestingly, the run showed the power commander map as provided by Ferracci was very good and really didn't need to be tweaked. Actually, the curves are nice and smooth. You can see I gained a nice chunk of torque and power across the rev range. In fact, you can see smack in the mid range at 5000 RPM a 7.8 ft-lb torque gain and a 8.2 hp gain. At that RPM this is a more than an 17% gain in horsepower and torque!
Some of this looks to be due to the really lousy stock air fuel ratio, but regardless, the FbF kit seems to have done a great job.
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