Another stripped liner thread about OS
11-25-2009 | 04:12 PM
#1
Thread Starter
Senior Member
Another stripped liner thread about OS
Well I was using OS 91 FX, the break in was done with 15% nitro and 20% all castor oil from sig.
It started to make friction noises right during the break in, people at the field said its normal for this engine and it was flying normal but didn’t reach high rpm, the airplane is 4*60 so I didn’t need much performance from it.
Fuels I used: Sig 15% all castor (two cases), Omega 15%, cool power 15%.
I’m not a beginner any more to know to run the engine on the rich side and to use after run oil at the end of every flying day.
The friction noises continued but it was flying well, now 9 months later at the end of the flying season I decided to send the engine for inspection, I’m getting this bill of repair:
• PISTON 91FX
• PISTON RING 91FX
• CYLINDER LINER 91FX
• REAR BEARING 61-300
• PSTN PIN RTNR 61RXSX
How do you ruin all these parts if you are not running it lean is beyond me.
Speaking to the hobby services they said maybe I didn’t use after run oil, totally incorrect I’m using after run oil religiously a lot, than maybe you run it on high RPM – also incorrect this airplane doesn’t need high RPM I was using 14x8 prop.
Hobby services said OS wont accept it under warranty.
The total is nasty almost the price of a new engine.
I don’t think I did something wrong especially the friction noises started while breaking in.
More important why pay the price of an OS if the warranty is so bad, or what did I do wrong?
For your thoughts and input.
Thanks
Alex
11-25-2009 | 04:35 PM
#3
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My Feedback: (19)
RE: Another stripped liner thread about OS
ORIGINAL: Alex7403
or what did I do wrong?
or what did I do wrong?
11-25-2009 | 04:41 PM
#4
Thread Starter
Senior Member
RE: Another stripped liner thread about OS
Yes maybe it is time to jump ship.
what trouble if its doing it during break in?
I dont buy top notch engines at top prices to send it back I want to fly them.
I dont know why to repair it if I can add $30 for a new engine, what only one flying season and need for a repair at a price of a new engine?
maybe it is time to jump ship.
Alex
what trouble if its doing it during break in?
I dont buy top notch engines at top prices to send it back I want to fly them.
I dont know why to repair it if I can add $30 for a new engine, what only one flying season and need for a repair at a price of a new engine?
maybe it is time to jump ship.
Alex
11-25-2009 | 05:08 PM
#7
Senior Member
RE: Another stripped liner thread about OS
Strange, this is not common for the 91 FX as it is ringed and has a steel liner, so this is not the usual peeling syndrome that is haunting OS. I have a 91FX myself and I am very happy about it. Anyway high rpm alone can not have caused this, I have ran mine at almost 13000 rpm on 13-6 props and it has no problems in doing this.
I have no idea what happened here, pictures would be great.
I am alittle puzzled by your mates telling you that the making of "friction noise" is normal for this engine. There was no such thing with mine, not during run-in or later. My guess is that there was something wrong with your engine from the very first start.
It is never cost effective to repair an OS, maybe a ring or the bearings, but otherwise just get a new engine.
I have no idea what happened here, pictures would be great.
I am alittle puzzled by your mates telling you that the making of "friction noise" is normal for this engine. There was no such thing with mine, not during run-in or later. My guess is that there was something wrong with your engine from the very first start.
It is never cost effective to repair an OS, maybe a ring or the bearings, but otherwise just get a new engine.
11-25-2009 | 05:25 PM
#8
Senior Member
My Feedback: (14)
RE: Another stripped liner thread about OS
ORIGINAL: Alex7403
Well I was using OS 91 FX, the break in was done with 15% nitro and 20% all castor oil from sig.
It started to make friction noises right during the break in, people at the field said its normal for this engine and it was flying normal but didn’t reach high rpm, the airplane is 4*60 so I didn’t need much performance from it.
Fuels I used: Sig 15% all castor (two cases), Omega 15%, cool power 15%.
I’m not a beginner any more to know to run the engine on the rich side and to use after run oil at the end of every flying day.
The friction noises continued but it was flying well, now 9 months later at the end of the flying season I decided to send the engine for inspection, I’m getting this bill of repair:
• PISTON 91FX
• PISTON RING 91FX
• CYLINDER LINER 91FX
• REAR BEARING 61-300
• PSTN PIN RTNR 61RXSX
How do you ruin all these parts if you are not running it lean is beyond me.
Speaking to the hobby services they said maybe I didn’t use after run oil, totally incorrect I’m using after run oil religiously a lot, than maybe you run it on high RPM – also incorrect this airplane doesn’t need high RPM I was using 14x8 prop.
Hobby services said OS wont accept it under warranty.
The total is nasty almost the price of a new engine.
I don’t think I did something wrong especially the friction noises started while breaking in.
More important why pay the price of an OS if the warranty is so bad, or what did I do wrong?
For your thoughts and input.
Thanks
Alex
Well I was using OS 91 FX, the break in was done with 15% nitro and 20% all castor oil from sig.
It started to make friction noises right during the break in, people at the field said its normal for this engine and it was flying normal but didn’t reach high rpm, the airplane is 4*60 so I didn’t need much performance from it.
Fuels I used: Sig 15% all castor (two cases), Omega 15%, cool power 15%.
I’m not a beginner any more to know to run the engine on the rich side and to use after run oil at the end of every flying day.
The friction noises continued but it was flying well, now 9 months later at the end of the flying season I decided to send the engine for inspection, I’m getting this bill of repair:
• PISTON 91FX
• PISTON RING 91FX
• CYLINDER LINER 91FX
• REAR BEARING 61-300
• PSTN PIN RTNR 61RXSX
How do you ruin all these parts if you are not running it lean is beyond me.
Speaking to the hobby services they said maybe I didn’t use after run oil, totally incorrect I’m using after run oil religiously a lot, than maybe you run it on high RPM – also incorrect this airplane doesn’t need high RPM I was using 14x8 prop.
Hobby services said OS wont accept it under warranty.
The total is nasty almost the price of a new engine.
I don’t think I did something wrong especially the friction noises started while breaking in.
More important why pay the price of an OS if the warranty is so bad, or what did I do wrong?
For your thoughts and input.
Thanks
Alex
Ringed OS engines utilize steel, non plated, liners. No peeling was/is possible, IF the engine was a ringed version. I don't know if they even sell such a critter.
As others have indicated, you should have stopped running the engine at the first weird noise sound and sent it back to Hobby Services. I take it that your engine is old enough to be out of warranty? In the past, Hobby Services has been very lenient with customers (fellow club members) and repaired their out of warranty engines for next to nothing if the customer had not created the problem initially. That does not mean that things (policies) cannot change, so I'm not inferring that you are telling an untruth.
The OS Engines importer's behavior and OS Engine's products are not the same as they used to be. But they still have some products that are worth the extra price. At least they do to me. Other's opinions may vary.
Ed Cregger
11-25-2009 | 05:26 PM
#9
My Feedback: (20)
RE: Another stripped liner thread about OS
ORIGINAL: w8ye
Time to jump the ship and buy something different.
Have them send it back
Time to jump the ship and buy something different.
Have them send it back
Unload all of your other OS engines as well.
For the price of a good used OS you should be able to buy a "Brand New" Chinese engine.
Lord knows that poor country can use the money. I find it amazing that it flew for 9 months "making friction noises" and it didn't grenade itself....
Alex, it sucks that your engine broke. I can understand how you feel. You did your best to break it in properly and take care of it afterwards.
I'd have them send it back so you can try and figure out what happened to it. It may just need a ring and a rear bearing. I've got a lathe and a Sunnen hone. Maybe we can repair it.
11-25-2009 | 05:37 PM
#11
Thread Starter
Senior Member
RE: Another stripped liner thread about OS
The 91 FX flew and still flying well, I mean if I need to change all the moving parts at a price of a new engine maybe to get a new 91 thunder tiger...
Its flying pretty good for something that needs this kind of repair.
Alex
Its flying pretty good for something that needs this kind of repair.
Alex
11-25-2009 | 05:38 PM
#12
Thread Starter
Senior Member
RE: Another stripped liner thread about OS
The engines with these problem that I've torn down, the obvious initial failure was the rear bearing cage. All the little metal shavings went up through the engine and ruined everything else
In this case I'll see signs and scratches in the inside of the engine block, I'm sure they would be happy to fix it though but I rather have a new engine for that amount of money, $146 instead of having a ruined one .
I most likely ask them to send it back and use the money for a new Thunder Tiger pro 91 instead.
11-25-2009 | 06:01 PM
#13
My Feedback: (20)
RE: Another stripped liner thread about OS
You have to figure that the service guy gets paid to replace the parts, not try and save them. Like you say it was still flying pretty good. Maybe a hone and a Bowman oversize ring will have it running better than new. Bowman rings are as good or better than the originals.(very reasonalble) Bearings are cheap. I've knurled the piston skirt on engines before to "grow" them in a bore that has been honed.
I believe the FX 91 has been discontinued, the price of parts will come down. the engine isn't costing you anything to just hold on to it.
Just my opinion...
I believe the FX 91 has been discontinued, the price of parts will come down. the engine isn't costing you anything to just hold on to it.
Just my opinion...
11-25-2009 | 06:14 PM
#16
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RE: Another stripped liner thread about OS
I've got this on my FS60 and it flies it just fine. The one I have has the silver rocker cover but everything else is the same.
http://www.hobbypeople.net/gallery/210868.asp
I would dump the the .91FX for this. I've literally got approx 75 to 100 hours on this engine and have adjusted the valves twice. When it eventually does wear out, a new piston, ring and bearings are approx $45. I've also got a OS 91 fs and I'll never buy another one as long as I can get this Magnum for half the price and as far as I can tell, the Magnum runs every bit as good as the OS. YMMV.
Edit: The OS does look better on the outside than the Magnum.
http://www.hobbypeople.net/gallery/210868.asp
I would dump the the .91FX for this. I've literally got approx 75 to 100 hours on this engine and have adjusted the valves twice. When it eventually does wear out, a new piston, ring and bearings are approx $45. I've also got a OS 91 fs and I'll never buy another one as long as I can get this Magnum for half the price and as far as I can tell, the Magnum runs every bit as good as the OS. YMMV.
Edit: The OS does look better on the outside than the Magnum.
11-25-2009 | 06:18 PM
#17
RE: Another stripped liner thread about OS
20 years ago i would run nothing but OS engines....today you couldn't give me an OS with the exception of the twins and radial which i have run and had excellent results.
the excuses Hobbico is giving you is so bunk, i'd scream bloody murder as this problem has been documented to death.
the excuses Hobbico is giving you is so bunk, i'd scream bloody murder as this problem has been documented to death.
11-25-2009 | 06:42 PM
#18
My Feedback: (20)
RE: Another stripped liner thread about OS
ORIGINAL: summerwind
20 years ago i would run nothing but OS engines....today you couldn't give me an OS with the exception of the twins and radial which i have run and had excellent results.
the excuses Hobbico is giving you is so bunk, i'd scream bloody murder as this problem has been documented to death.
20 years ago i would run nothing but OS engines....today you couldn't give me an OS with the exception of the twins and radial which i have run and had excellent results.
the excuses Hobbico is giving you is so bunk, i'd scream bloody murder as this problem has been documented to death.
11-25-2009 | 06:46 PM
#19
RE: Another stripped liner thread about OS
you know, i think all i got left is a few NIP valve springs..you can have em
funny too is that there are maybe 2 pages of listings (12-90 ads) for all other engine makes on the bay(and here on RCU), but there always seems to be 300 or more listings for OS all the time.
funny too is that there are maybe 2 pages of listings (12-90 ads) for all other engine makes on the bay(and here on RCU), but there always seems to be 300 or more listings for OS all the time.
11-25-2009 | 06:54 PM
#20
My Feedback: (20)
RE: Another stripped liner thread about OS
ORIGINAL: summerwind
you know, i think all i got left is a few NIP valve springs..you can have em
funny too is that there are maybe 2 pages of listings (12-90 ads) for all other engine makes on the bay(and here on RCU), but there always seems to be 300 or more listings for OS all the time.
you know, i think all i got left is a few NIP valve springs..you can have em
funny too is that there are maybe 2 pages of listings (12-90 ads) for all other engine makes on the bay(and here on RCU), but there always seems to be 300 or more listings for OS all the time.
I believe it. You can't get anything for a used Chinese engine...
Were you able to find a rod for that NIB Super Tigre?
I made the rod in the center for an OS H-80 engine. It didn't need it as the big end uses a needle bearing. The later model engines came with a bushed rod. I converted one of the other 80's I have to dual piston ring, needle bearing rod.
If you get stuck I can make a rod for you...
11-25-2009 | 11:23 PM
#21
RE: Another stripped liner thread about OS
hi i run a 13/7 APC ON MY OS 91- 12,100 RPMSthe 14/6 might be too much prop-the 91 had an issue with a need to change the nv 'o' ringas they were leaking when the engines were first soldyou had to change the green 'o' ring -to a black one that os would send you as a replacementair in a new engine will cause much heat build up and damage the moving parts i might add the engine never had a good sound on the stock mufflera kind of strange harmonic that i did not at all care fortook away from enjoying flying the engine-until i put a max black muffler on the engine-now i just love the sound of the engine in my 60 ULTRASPORT
11-25-2009 | 11:35 PM
#22
Senior Member
My Feedback: (2)
RE: Another stripped liner thread about OS
if the engine still runs have them ship it back. if it flies your plane fine who cares if it isnt perfect? just run it till it stops working all together, then buy a new engine.
it may last a while even though its messed up.
it may last a while even though its messed up.
11-26-2009 | 03:53 AM
#23
Senior Member
My Feedback: (14)
RE: Another stripped liner thread about OS
ORIGINAL: Alex7403
The 91 FX flew and still flying well, I mean if I need to change all the moving parts at a price of a new engine maybe to get a new 91 thunder tiger...
Its flying pretty good for something that needs this kind of repair.
Alex
The 91 FX flew and still flying well, I mean if I need to change all the moving parts at a price of a new engine maybe to get a new 91 thunder tiger...
Its flying pretty good for something that needs this kind of repair.
Alex
If it is still flying well, why not just continue to fly it until it dies a natural death? Then prop it up with a minimum of parts and fly it again until it dies. I'll betcha it'll come close to outlasting you.
I'm guilty of driving old cars until they won't wiggle any longer. Then I buy a minimum number of parts (used if I can find some with some life left in them) and get the old clunker going again. Yes, I was an auto mechanic, so I did the work myself, saving labor costs too. Some of my R/C buddies used to kid me about some of the clunkers I drove and hounded me to buy a nicer car. I told them to all get together and figure out just how much money they could muster every month to make a car payment for me. That shut them up.
Sorry for going way off topic, but what I'm trying to convey is that if your engine is running well, why fix it? Just fly it.
Ed Cregger
11-26-2009 | 12:41 PM
#24
Thread Starter
Senior Member
RE: Another stripped liner thread about OS
perfectionism led me to send it to them now I'm paying for it.
yes it looks like I just ask them to send it back and I'll fly it till it stops.
Thanks
Alex
yes it looks like I just ask them to send it back and I'll fly it till it stops.
Thanks
Alex
11-26-2009 | 12:46 PM
#25
RE: Another stripped liner thread about OS
I don't quite understand the "friction noise"?
The only odd noise one may hear is when the bearings are bad. Can't imagine that one would actually hear the piston travelling inside the liner...?
If/when you get the engine back you could replace the bearings and give a another go...
The only odd noise one may hear is when the bearings are bad. Can't imagine that one would actually hear the piston travelling inside the liner...?
If/when you get the engine back you could replace the bearings and give a another go...
