912 exhaust connections

[kmach]

The safety wire is very important on a pusher configuration, it keeps the larger broken spring part from going through the propeller.

I do mine on the Kitfox, it would keep a broken spring so you could inspect to see were it broke. I've never had one break though, I do change them if they get any groove wore in the hooks.

[fastfred]

Anyone ever have a spring break? Good insurance but they look similar to a snowmobile spring and I have never had one break in 30 years of riding them. They are expose to heat and rust.

[avidflyer]

I think they are far more likely to break on a pusher configuration where the little devils have the most chance of doing damage, especially if you didn't safety wire them. I've never had one break on me either, but have removed some that were quite worn, and if left to themselves would have eventually called it quits. I think the silicone will help keep them from vibrating and therefor have less wear. JImChuk

[jiott]

I have replaced several that were on the verge of breaking; and I have had the silicone on from day 1, now 660 hours.

[cap01]

i just had to remove the exhaust system to repair some cracks and a couple of the springs were worn so bad that there was so little metal left i could hardly see it, i don't know why they hadn't let go. they had almost 1100 hrs on them and had the hi temp silicone on them. when i installed the pipes i used silver anti seize

[fastfred]

I would probably plan on replacing the springs more often but still I have not heard of one breaking.1100 hours is pretty good on a $3 spring

[Russell320]

Well....here it is...fresh off the airplane. What a pain that was. The cracks are from the two rear headers. Unfortunately, I don’t think I can save the muffler......a new one will be $795 from Kitfox and is custom made for your headers. It takes about 3 weeks. My guess is the cracks are from the slip joints not slipping. The muffler is from the early 90’s, so I’m not willing to fix it and then have it crack again from age. But......I may change my mind.

Mouse milk, mapp gas and a week of soaking finally did the trick. Did I mention it was a pain?

[Russell320]

Yep....tried all that too. Using Pete’s idea with a 3/8th nut,bolt and socket. Using mapp torch hasn’t worked, so acetylene is next. Thanks for your suggestions....keep em’ coming!

BTW...don’t expand too far with this setup....you’ll bend the tab into the header.

[avidflyer]

I can't imagine that the bolt as you show it between the spring tabs plus heat from a torch wouldn't work. Unless it somehow welded it's self together. (not likely) Show us pictures of your success! JImChuk

[jiott]

Have you tried an ice cold towel on the header pipe and some heat on the muffler port, along with the penetrating oil?