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Barn of Parts Sled Salvage LLC

11-18 Apex Exhaust Repair Flanges

The 11-18 Apex header is prone to having the flared ends crack over time. Unfortunatly the OEM header is a 4 into 1 assembly with exup valve and has a current list price of near $5500. We have developed replacement flanges that allow one to easily fix a broke flange at an affordable price.  These flanges are machined to fit inside the pipe once you cut off the old flange.  Once the flange is installed 3 holes get drilled on top side and then on bottom side so there are 6 stainless steel rivets securing the flange to the pipe. 

There was a similar product on the market at one time for the 06-10 headers but they slipped over the OD of the pipe. By inserting our flanges inside, there is less of a chance for leaks as the exhaust gas has to make a 180 degree turn against flow to leak at the joint. In addition, the differing thermal expansion rates between the flange and pipe will also work in our favor to create a tighter seal. 

These flanges are being sold individually so you only have to buy what you need. If 3 of your 4 flanges are good you do not have to replace all of them at the same time.  Retail for one flange with rivets is $100.

riveted flange.jpg

Once the flange is inserted it gets secured with 1/8" rivets. Photo showing orientation of rivets on top side of pipe. Bottom side gets 3 more in same orientation. When drilling the holes for rivets do one at a time and insert rivet before drilling next hole. 

flange cut line.jpg

This photo shows where to cut the old flare off. The old flange gets cut right where the OD of pipe steps down to 1.5" diameter. If doing multiple flanges only remove one at a time. This allows you to use some sort of straight edge as a reference against the remaining flanges to locate the replacement flange. Beings these mate up with flex pipes there is some forgiveness, so don't loose sleep if one flange ends up a little crooked.

Yamaha 4 Stroke Snowmobile Specialists

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