Having occasionally been guilty of posting a rant about disappointing aircraft parts and customer service culture (or lack of it) from makers (particularly Rotax) or vendors (see my old rant about Rotax’s dismal customer-unfriendly policies elsewhere in the forum*) it seems only fair to offer positive feedback when it’s due.
Back in 2015 after our Rotax manufactured exhaust system broke we purchased one from CKT Engineering (https://www.cktengineering.com) in England. (They custom configure them for various different aircraft, as headers, etc., don't always run the same in different cowls, etc.)
We got the optional cabin heater shroud/system. A bit more costly than the Rotax... especially with the optional heater kit.
On the customer-service part of this story, we got a good taste in our mouth right off the bat: Shortly after we installed the new exhaust Rotax had just slightly increased the length of their oil filters such that it became impossible to spin on the new filter without removing the exhaust header closest to it. This was a Rotax caused problem. Yet CKT re-fabricated a new header pipe for us with the slight extra clearance and didn't charge us for it or even shipping.
As for our experience with the exhaust itself: It is noticeably quieter than the Rotax system it replaced. And though we can't objectively document this, it seems to give us a tad more power.
I've often said you only find out what sort of company or service provider you're dealing with when there's a problem. Well, some months ago we detected very slight seepage of coolant right at one of the joint between the header and a rear exhaust manifold port on the header. (With hindsight it appears what happened is perhaps the joint where the exhaust header entered the muffler that joint froze {insufficient anti-seize?} allowing vibrations to go up to where the hard stainless steel header entered the head, and slowly gouged/shaved its way into the softer aluminum seat and put a pinhole into the water jacket. It looked like this was going to be expensive and slow to remedy ... likely a rebuilt head. Worst case a new $3000 head from Rotax.
Contacted CKT with photos and description of the issue. .. perhaps at best hoping they'd supply a new header pipe as its top end was a bit worn.
An engineer there replied promptly. He said/recommended that we install a stainless steel sleeve in the exhaust port of the header. After several email and more photos revealing the pinhole they recommended we put a particular JB-Weld type epoxy under the sleeve when we seat it, and ,for good measure, use a high temp copper/silicone gasket compound between the header and and the sleeve. Held our hands all the way. They assured us that they had personally actually used the Gorilla-Weld epoxy on other occasions similar with success.
Shipped us a new header pipe and the sleeve at no charge. (Can you imagine Rotax doing that? Or even being able to talk to an engineer there?)
It was a bit of a fidgety job to get it all together (the rear facing exhaust port had not much clearance and visibility and we had to carefully lightly polish the head's exhaust port seat before seating the sleeve.
Bottom line is the repair worked perfectly (as evaluated many hours later still), and it was CKT pulled our cookies out of the fire. Total cost to us basically one tube of Gorilla-Weld and one tube of high temp copper silicone sealer.... Under $25.
Alex
* My old rant about how badly Rotax treats its customers is at
https://www.rotax-owner.com/en/rotax-owner-community/5274-a-rant-about-rotax-lack-of-owner-support
