DA85 MUFFLER ISSUES
10-06-2008, 01:18 PM
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DA85 MUFFLER ISSUES
I am now convinced that there is no good pitts style muffler for DA 85. The characteristic vibrations on this engine will cause muffler to crack and break. Between the two people in my club we have gone through three slimlines and a Jtec and they all broke. Slimlines are mainaly cracking at the far outlet pipe weld seam and JTEC is cracking at the input weld seam.
I believe its time for DA/Slimline and JTEC to really tighten their belts and address this issue. This is a new engine and the sooner the problem gets attention and resolution comes, the less customer dissatisfaction will arise. This problem will not go away by itself. It must be addressed.
I like to hear any suggestion or ideas threaders have or maybe post pictures of your home made solutions until we get some real resolution from the MAN.
thanks
Jason
I believe its time for DA/Slimline and JTEC to really tighten their belts and address this issue. This is a new engine and the sooner the problem gets attention and resolution comes, the less customer dissatisfaction will arise. This problem will not go away by itself. It must be addressed.
I like to hear any suggestion or ideas threaders have or maybe post pictures of your home made solutions until we get some real resolution from the MAN.
thanks
Jason
10-06-2008, 02:26 PM
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RE: DA85 MUFFLER ISSUES
http://troybuiltmodels.com/newsite/pitts_bracket.html
Though Slimline says not to bracket their muffler.
Though Slimline says not to bracket their muffler.
10-06-2008, 05:10 PM
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RE: DA85 MUFFLER ISSUES
How many gallons do you have through your motors with those mufflers?
We have 3 JTEC pitts (normal, not large size) in our club. I have 6 gallons through mine, and the other two have about 4 gallons.
We did have some initial issues with the mufflers coming loose, but after some red loc-tite the loose bolt problem was solved.
Otherwise so far so good.
Joe
We have 3 JTEC pitts (normal, not large size) in our club. I have 6 gallons through mine, and the other two have about 4 gallons.
We did have some initial issues with the mufflers coming loose, but after some red loc-tite the loose bolt problem was solved.
Otherwise so far so good.
Joe
10-06-2008, 05:30 PM
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RE: DA85 MUFFLER ISSUES
ORIGINAL: wind junkie
How many gallons do you have through your motors with those mufflers?
We have 3 JTEC pitts (normal, not large size) in our club. I have 6 gallons through mine, and the other two have about 4 gallons.
We did have some initial issues with the mufflers coming loose, but after some red loc-tite the loose bolt problem was solved.
Otherwise so far so good.
Joe
How many gallons do you have through your motors with those mufflers?
We have 3 JTEC pitts (normal, not large size) in our club. I have 6 gallons through mine, and the other two have about 4 gallons.
We did have some initial issues with the mufflers coming loose, but after some red loc-tite the loose bolt problem was solved.
Otherwise so far so good.
Joe
Joe,
I have about 8 Gallons through mine and it just broke. The other guy at our club has app . 15 Gals. He broke his first slimline after 4 gals. second slimline after 6th and this JTEC was supposed to be made for him with extra enforcement and it lasted about 4 gallons.
I dont beleive this issue is related to bracketing. It is probably caused by high frequency vibrations and their harmonics propagating and amplifying throught the material. I think they need to just reinforce the weld lines with metal backing.
Jason
10-06-2008, 05:49 PM
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RE: DA85 MUFFLER ISSUES
Jason,
Looks like we may be in for this also judging from your experience. Thanks for the warning.
We got the JTECS because they were the lightest available. Maybe that's just "too light" after all.
Looks like we may be in for this also judging from your experience. Thanks for the warning.
We got the JTECS because they were the lightest available. Maybe that's just "too light" after all.
10-07-2008, 05:53 PM
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RE: DA85 MUFFLER ISSUES
ORIGINAL: rcairflr
I had mine rewelded, I think the welds on these mufflers is way too thin. I've got about 6 gallons thru it since reweld.
I had mine rewelded, I think the welds on these mufflers is way too thin. I've got about 6 gallons thru it since reweld.
RC
Looks great. may be you should forward this photo to Slimline. Since they told me this morning they are trying to redesign the weld seam. they said this is the third redesign..
jason
10-07-2008, 07:24 PM
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RE: DA85 MUFFLER ISSUES
ORIGINAL: Da ROOK
RC
Looks great. may be you should forward this photo to Slimline. Since they told me this morning they are trying to redesign the weld seam. they said this is the third redesign..
jason
ORIGINAL: rcairflr
I had mine rewelded, I think the welds on these mufflers is way too thin. I've got about 6 gallons thru it since reweld.
I had mine rewelded, I think the welds on these mufflers is way too thin. I've got about 6 gallons thru it since reweld.
RC
Looks great. may be you should forward this photo to Slimline. Since they told me this morning they are trying to redesign the weld seam. they said this is the third redesign..
jason
Good idea, I just did exactly that.
10-11-2008, 02:37 PM
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RE: DA85 MUFFLER ISSUES
FYI, one of our JTEC pitts mufflers broke just today! My friend landed and saw his muffler hanging supported only by the cowl, but then reached inside and tossed me the entire cannister which had broken away from the mount.
The timing of this has been uncanny....
The timing of this has been uncanny....
10-15-2008, 10:59 PM
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RE: DA85 MUFFLER ISSUES
I have a TBM Silent beauty pitts and it cracked after ~1 gallon thru.
The prop is balanced and the hub is also.
Running the engine just so ever slightly on the rich side.
After the muffler cracked at a weld joint, I went back to the site to get phone number and seen the new updated bracket requirement.
I welded up and will continue to fly it, in the mean time going to make my own but a few oz's heavier.
Use similar design just thicker material and a little more volume.
The prop is balanced and the hub is also.
Running the engine just so ever slightly on the rich side.
After the muffler cracked at a weld joint, I went back to the site to get phone number and seen the new updated bracket requirement.
I welded up and will continue to fly it, in the mean time going to make my own but a few oz's heavier.
Use similar design just thicker material and a little more volume.
10-22-2008, 12:02 PM
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RE: DA85 MUFFLER ISSUES
Not so far, but the vibration is higher than usual for any engine I owned. I am checking the header and canister after every flight.
It also transmits vibrations into the fuse through the canister, which is not good...
I am having a heck of a time finding the right needle settings. I have some weird missing or surging at about 1/3 throttle that I cannot seem to be able to get rid of. I went to both the righ side and the lean side and nothing seems to help.
It also transmits vibrations into the fuse through the canister, which is not good...
I am having a heck of a time finding the right needle settings. I have some weird missing or surging at about 1/3 throttle that I cannot seem to be able to get rid of. I went to both the righ side and the lean side and nothing seems to help.
ORIGINAL: jrjohn
Just bought a DA-85 today, this muffler issue is not good news. I wonder if the guys using a canister with a flex header are experiencing cracked headers??
John
Just bought a DA-85 today, this muffler issue is not good news. I wonder if the guys using a canister with a flex header are experiencing cracked headers??
John
10-22-2008, 12:09 PM
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RE: DA85 MUFFLER ISSUES
ORIGINAL: yarom
Not so far, but the vibration is higher than usual for any engine I owned. I am checking the header and canister after every flight.
It also transmits vibrations into the fuse through the canister, which is not good...
I am having a heck of a time finding the right needle settings. I have some weird missing or surging at about 1/3 throttle that I cannot seem to be able to get rid of. I went to both the righ side and the lean side and nothing seems to help.
Not so far, but the vibration is higher than usual for any engine I owned. I am checking the header and canister after every flight.
It also transmits vibrations into the fuse through the canister, which is not good...
I am having a heck of a time finding the right needle settings. I have some weird missing or surging at about 1/3 throttle that I cannot seem to be able to get rid of. I went to both the righ side and the lean side and nothing seems to help.
ORIGINAL: jrjohn
Just bought a DA-85 today, this muffler issue is not good news. I wonder if the guys using a canister with a flex header are experiencing cracked headers??
John
Just bought a DA-85 today, this muffler issue is not good news. I wonder if the guys using a canister with a flex header are experiencing cracked headers??
John
I'm talking to one muffler manufacturer about building a side muffler, (simular to the stock DA-50 muffler) the weight would be nearly half of a pitts wrap around and much less prone to cracking. In addition to that, little or no cowl hacking in order to get it to fit. I wonder how many guys would be interested in this style muffler?
10-22-2008, 06:39 PM
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RE: DA85 MUFFLER ISSUES
ORIGINAL: jrjohn
I'm talking to one muffler manufacturer about building a side muffler, (simular to the stock DA-50 muffler) the weight would be nearly half of a pitts wrap around and much less prone to cracking. In addition to that, little or no cowl hacking in order to get it to fit. I wonder how many guys would be interested in this style muffler?
ORIGINAL: yarom
Not so far, but the vibration is higher than usual for any engine I owned. I am checking the header and canister after every flight.
It also transmits vibrations into the fuse through the canister, which is not good...
I am having a heck of a time finding the right needle settings. I have some weird missing or surging at about 1/3 throttle that I cannot seem to be able to get rid of. I went to both the righ side and the lean side and nothing seems to help.
Not so far, but the vibration is higher than usual for any engine I owned. I am checking the header and canister after every flight.
It also transmits vibrations into the fuse through the canister, which is not good...
I am having a heck of a time finding the right needle settings. I have some weird missing or surging at about 1/3 throttle that I cannot seem to be able to get rid of. I went to both the righ side and the lean side and nothing seems to help.
ORIGINAL: jrjohn
Just bought a DA-85 today, this muffler issue is not good news. I wonder if the guys using a canister with a flex header are experiencing cracked headers??
John
Just bought a DA-85 today, this muffler issue is not good news. I wonder if the guys using a canister with a flex header are experiencing cracked headers??
John
I'm talking to one muffler manufacturer about building a side muffler, (simular to the stock DA-50 muffler) the weight would be nearly half of a pitts wrap around and much less prone to cracking. In addition to that, little or no cowl hacking in order to get it to fit. I wonder how many guys would be interested in this style muffler?
Sounds very interesting. It would have to not lose any more power than the Pitts style muffler and be quieter.
This would work very well on my QQ 101" Yak-54
Any time frame for availability?
10-22-2008, 07:29 PM
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RE: DA85 MUFFLER ISSUES
Rc, I doubt you would loose any power, you might even pick up a little. I know on the DA-50 the Stock side muffler makes about 300 more rpm's with a given prop over the pitts style. As for quieter..... thats not going to heppen, if anything I would expect a little more noise. If the project goes through, I would expect something in the next few months. You would be dropping nearly a pound over a canister setup when you include the canister, header, couplers, mounts, clamps ect. Thats a lot of weight! Probably 6-7 ounces liter than the pitts muffler including supports.
John
John