DA-85 Canister Mounting Issues. Help Guys....

[Paul Cataldo]

Ok guys,
I'm installing a KS95 canister into my Aeroworks 75cc Extra 260, using the supplied plywood formers. This setup requires the MTW 50mm drop, double bend FLEX header from DA, which I just received from DA today.

Here are my questions:

1. Is the teflon tape that is wrapped around the flex portion of the header going to start turning brown and leaking on me? IF SO, then what is the fix? Is this a constant maintanence item, where the teflon wrap is going to have to constantly be replaced over and over again? IF SO, then approximately how many flights will the teflon tape last? Are we talking 5 flights, or 50 flights???? (ballpark it guys).

2. Aeroworks supplied 8 short pieces of clear tubing, about 1/2" in diameter, and about 1" long each. 4 of these pieces are used on each canisters plywood mount, in order to soft-mount the canister. I'm sure you've all seen this use for silicone tubing. Most guys use this stuff to soft mount their canisters in the plywood formers.
WHAT EXACT MATERIALS can I use to replace this tubing?? (some of them are torn, and some were too short. I CANNOT use the ultra-small Aerotrend fuel tubing, as it's TOO SMALL in diameter).
WHAT can I use to replace this clear tubing???? Is it PURE SILICONE tubing? Does anyone know of an R/C company that supplies it? How about hardware stores? Would ANY local store possibly have something that will work, and withstand the heat from the canisters? I have searched the forum, and the ONLY material I saw recommended, was blue Aerotrend fuel tubing. As stated, I need something about 1/2" in diameter, as it fits my plywood mounts, and the canisters diameter perfectly. (this is why Aeroworks used it)

3. Is my KS95 canister going to develop DENTS from vibration and the plywood mounts? I have had guys tell me that ALL CANISTERS will eventually develop DENTS, from vibration, right where the canister runs through the plywood mounts.
Does everyone here feel like most ANY canister setup in a plane is eventually going to become dented, OR is this uncommon, and a sign of a bad install? This plane uses TWO plywood formers, so the canister is mounted fairly securely.
The reason I ask, is because I noticed a small dent in the canister, the second I opened it up out of the box from DA. Should I send it back, or is there going to be dents in my canister anyway??????

Thanks so much for your help guys. I just want to confirm a few things before I proceed with this install.
Hope to hear back from some of you.

[aerolou2]

Hello, Among the airplanes we currently fly there is a SD 33% Yak with the DA-85, To answer your first question the teflon wrap is definitely a consumable item, Discolored after 5 to 8 flights , Will need replacement in about 15 to 20. I prefer a 1 piece header if it is available just for that reason. If properly mounted with the right silicone hose snubbers the can should be trouble free, You can get the correct material from Desert aircraft. You will find that not only is this engine as powerfull as you have heard but it is also very smooth which helps exhaust components last longer. Fyi I recomend retorquing the carb mounting bolts after the first several flights as it is normal for the plastic reed block to take a slight set. Wish you best of luck.
Lou Verdiales

[Paul Cataldo]

Yes, I'm aware that Desert Aircraft carries the tubing, but they are out of stock on it, or VERY LOW, and I don't think they have any to ship out right now.
There has GOT to be something else that can be used... (or another popular source for the stuff.) I suppose any silicone tubing will work????

[bodywerks]

I am running flex headers on my 35% 260 with tuned pipes. In 175 flights, I have not touched the teflon wrap that origionally came on the headers, and there is not even on hint of one minuscule drop attempting to seep out of them - maintenance-free as far as I am concerned. Just leave the teflon on there and run the engine. The carbon running through the exhaust will tend to start sealing the flex section on it's own; the teflon is only there to help speed up this process.
As for the tubing, any pure silicone tubing should work just fine. there are other options of mounting the can that may even prove to be more vibration-dampening and less likely to induce dents. For example, check out the pics in this link:
http://www.flyinggiants.com/forums/370123-post102.html
With this method, you would probably have to enlarge the circle of each cannister mount and simply drill some 1/4" holes around its circumference and wrap the medium fuel tubing through them. It is how I plan to mount the pipes in my 42% Extra.
Every cannister I have ever seen ends up with a dent here or there. Around the mount contacts, creasing dents would be a sign of possibly an improper install, but a slight indentation where the rubber contacts the can is going to be fairly normal.
As for the dent that is already there, unless it looks like it was dropped off a roof, don't worry about it.

[Rolling Thunder]

KS mufflers dent very easy and it does not hurt performance. I have had some that were very beat up and they still work very well.

[Paul Cataldo]

Hey bodywerks,
Thanks for the link.
It is interesting, but honestly, it's basically the same old style of mounting canisters, just beefed up a little, with more support than usual.
THANKS for letting me know how long your teflon tape wrap has lasted. I had read some other posts on this forum, where some guys said their teflon wrap only lasted 8-10 flights or so.
Well guys, I guess I just never knew that canisters could get dented so easily, and it really hurts my badly to find out that these beautiful canisters can (and WILL) get dented so easily! I am thinking up some really cool methods for mounting the canisters, based off of a 3W can mount I saw online a while back. It's ULTRA COOL, and spreads the "load" of the pressure points on the canister out over a larger area, which really helps PREVENT this ugly denting of the canister during operation.
I just cannot bear the thought of dented cans. I suppose I will have to deal with it, but there are ways to mount the cans to prevent this. SOME would require TOO MUCH weight being added to the plane, while others are fairly lightweight, and would be ok, especially in a 40% sized plane.
I have been looking at these KS "ComfortMount" systems that really look cool, and I bet they work MUCH better than standard plywood mounts. Take a look. You must click on "KS Comfortmount" at the TOP of the page, and then after that page loads, click on the bottom link "KS Comfortmount Systems" I think. Take a look at the pics they show of the system installed. ALL that is needed is a flat plywood mount under the canisters, in order to have something to bolt the Comfortmounts too. That's IT. Nothing else appears to be needed for these to fit into a plane.
http://www.krumscheid-metallwaren.de...op.php?lang=EN

The ONLY problem I see, is that they might be too big and bulky, or just too heavy for my 33% AW's Extra 260.
However, I feel they would be SWEET for a 40%er.
What do you guys think? Strictly for 40%ers, or doable for smaller planes?


BTW, thanks bodywerks for the reply. I always look forward to your replies online. You've always got good valuable info to share...