I'm working on a 76 husqvarna 360. the exhaust is held on by 2 tension springs. AND a third compression spring on a bracket. but i cant tell how to mount the third spring. the spring could go between the exhaust and the bracket. forward of the bracket. I guess, im asking, should i mount the third spring to allow for forward movement? and what is the reason for that. should i mount it so the exhaust tap compresses the spring between the pipe and bracket? or should i mount so the through bolt is pulled forward by the exhaust, against the bracket? and why is a twostroke exhaust on springs anyway? i saw an old matador that had a spanner nut attachment, like a bmw airhead. heres a picture from another bike thanks guys?
Can you post a picture of the actual area? Is this an aftermarket exhaust that has an additional spring attachment point? I work on those bikes regularly and can't remember seeing one with more than two springs at the head. Dave
Oh, I get it. The bracket off the front frame tube. I have seen them assembled many different ways, though the idea is for the spring to keep tension on the exhaust mount point while also letting it vibrate. I imagine the tab would break off pretty quickly if it was just rigidly attached to the frame. I don't know that it so much matters how you assemble it, but I usually place the spring (and some washers) between the bracket and exhaust tab. I'll see if I can find a factory diagram that shows how they put them together.
So they show it bracket-to-bracket with the spring behind it. This image is for an 81, but the idea should be the same.
my parts diagram was too blurry! whats the reason for that anyway? just to reduce metal fatigue on the thin pipe?
Pipe heat is one of the design parameters and thin sheet metal expands a good bit. Spring mounting allows unfettered expansion as it heats up. Keeps the pipes from cracking not to mention some of the big single 2 strokes shake a bit. Todays materials and methods make it possible to run without them but it is still easier.
Another side benefit to spring-retained exhaust is the elimination of the possibilty of seized mounting collars and bolts found on other bikes. Another is so you can easily remove the exhaust with a screwdriver and pliers on the side of the road to see how scored your piston is after your seize it. DAMHIK
2stokes vibrate tomuch .... 3rd spring is longer? sometimes its placed on biggest part of tube to hold middle
Yup, that long, thin sheet metal tube resonates like crazy. The spring clamps and other rubber mounted bushings allows the pipe to "float" just a tiny bit to keep it from stress cracking.
The springs also make it hell of an easy to remove the pipe to service other items. Just bend up a hook tool on the long end of a long allen wrench. And being spring mounted the chamber can flex, probably reduceing damage in a crash. Not that I would know anything about crashing!! You can get a parts manual here for your bike: https://www.halls-cycles.com/Catalog/Halls-Cycles-Husqvarna.aspx The exploded views are worth a thousdand words. This is all you really need to service the bike. The service manual is prety breif ( like 10 pages ). I can email you a copy for an 86 if you send me your email. Here's my resto 86 Husky. rebuilt to ride, hard. Action vidio. Not for the faint at heart! http://www.youtube.com/watch?v=BVj21aQQC3A&feature=g-upl&context=G2353e6bAUAAAAAAABAA