Blubbery .50 SX
08-12-2002, 01:16 PM
#1
Blubbery .50 SX
I fired up a brand new OS .50SX on a PSP test stand this weekend. After running a very wet tank full I started following the manual's breakin process and passed another tankfull, alternating for 2-stroke rich to 4-stroke rich. The engine ran fine and ended up with a decent idle and fair high-end (suspect it needs more breakin before improvement).
With all that, I still have a problem. I have a significant fuel leak from the right side of the engine. While the engine is running there is a river of fuel that drips along the bottom of the muffler and I can see fuel bubbling around the pressure tap. I'm not real sure of the source, but suspect the muffler/exhaust connection. I made sure the muffler was tight. I even torqued the pressure valve a little and made sure the muffler bolt was secure (I added a split washer to the hold-in nut at the back of the muffler.) None of this seam to solve the fuel leak. I will try sealing the muffler and exhaust with gasket goop. BTW, after I ran the engine for a while I did find that little note tucked under the packing material of the box that said the carburetor was packed loose. I checked the carburetor connection and it was tight.
With all that, I still have a problem. I have a significant fuel leak from the right side of the engine. While the engine is running there is a river of fuel that drips along the bottom of the muffler and I can see fuel bubbling around the pressure tap. I'm not real sure of the source, but suspect the muffler/exhaust connection. I made sure the muffler was tight. I even torqued the pressure valve a little and made sure the muffler bolt was secure (I added a split washer to the hold-in nut at the back of the muffler.) None of this seam to solve the fuel leak. I will try sealing the muffler and exhaust with gasket goop. BTW, after I ran the engine for a while I did find that little note tucked under the packing material of the box that said the carburetor was packed loose. I checked the carburetor connection and it was tight.
08-12-2002, 07:48 PM
#2
My Feedback: (11)
Blubbery .50 SX
Jim,
If the fuel you're seeing is coming from the engine/muffler junction, you can easily make a gasket from rubberized high-temp gasket material, easily available from any auto parts store. If it's leaking from the pressure nipple, then your fuel tubing may be a bit on the large size.
Also, it would not really be "fuel", but oil from the exhaust stream. Any such leakage would not affect performance much, just make the model sloppy and dirty.
If it's raw, unburned fuel, you'll need to look more closely. Is the engine leaking from behind the drive washer? Can you feel a cool fuel spray if you hold your hand behind the propeller next to the cylinder? This is serious, and means that the engine has a bad crankshaft to case fit. You can see an oily coating on the backside of the propeller in many cases.
You'll need to check carefully to be sure of the source.
We hope you find this information helpful. Should you have any further questions or concerns, please do not hesitate to contact us at this email address. (Please be sure to copy all previous emails into any future questions.)
DID YOU KNOW that our web pages now all contain FAQs? (Frequently asked questions) Please drop by and take a look! We hope you'll find the information helpful and valuable to you.
Sincerely,
Bill Baxter, Manager
Hobby Services
1610 Interstate Dr.
Champaign, IL 61822
USA
Phone: 217 398-0007
Fax: 217 398-7721
Email: [email protected]
Web: http://www.bestrc.com
If the fuel you're seeing is coming from the engine/muffler junction, you can easily make a gasket from rubberized high-temp gasket material, easily available from any auto parts store. If it's leaking from the pressure nipple, then your fuel tubing may be a bit on the large size.
Also, it would not really be "fuel", but oil from the exhaust stream. Any such leakage would not affect performance much, just make the model sloppy and dirty.
If it's raw, unburned fuel, you'll need to look more closely. Is the engine leaking from behind the drive washer? Can you feel a cool fuel spray if you hold your hand behind the propeller next to the cylinder? This is serious, and means that the engine has a bad crankshaft to case fit. You can see an oily coating on the backside of the propeller in many cases.
You'll need to check carefully to be sure of the source.
We hope you find this information helpful. Should you have any further questions or concerns, please do not hesitate to contact us at this email address. (Please be sure to copy all previous emails into any future questions.)
DID YOU KNOW that our web pages now all contain FAQs? (Frequently asked questions) Please drop by and take a look! We hope you'll find the information helpful and valuable to you.
Sincerely,
Bill Baxter, Manager
Hobby Services
1610 Interstate Dr.
Champaign, IL 61822
USA
Phone: 217 398-0007
Fax: 217 398-7721
Email: [email protected]
Web: http://www.bestrc.com
08-13-2002, 05:52 PM
#3
This is a BRAND NEW engine???
Frankly, I'm just a little surprised at this response. Just to make myself clear, this is a BRAND NEW OS .50SX that I paid $159.00 for.
1.) Is this recommendation an indication that streaming oil from the muffler/exhaust junction for this engine is normal? I didn't see anything like that in my manual.
2.) The fuel tubing is relatively new and not the extra large version -- I use the same fuel line on my Saito FA-100 pressure tap with no oil/fuel leakage.
3.) At a minimum I do intend to put gasket sealing around the exhaust junction and between the 2 halves of the muffler. This will be my first OS engine that I've had to do this to out of ((3) LA .15s, (2) FP .25s, (3) FX .46s, (1) LA .65, (1) Surpass .70, (1) BX-1 1.08, and (1) FX 1.60.) The only other engines I've had to use gaskets with were a Magnum XL .15, a Magnum XL .25, a Magnum XL 1.08 and a Magnum XL 1.20.
I'm not sure your correct here -- it is my impression that it is both raw fuel and excessive oil, i.e., oil percentage is much higher than the raw fuel alone. I was, after all, breaking in the engine and running it regularly from a 4-stroke mode. I'm not sure whether this is causing a performance hit because I don't know what I should be getting for high-end at this time. I do know I'm not yet getting what I currently get from a well-broken in FX .46.
This is definetely not acceptable. This engine is going into an enclose cowl on an OK Models EZ 3D Cap.
Though I am not absolutely certain, I did look very carefully in that area, both the front bearing and carburetor, and could not detect and fuel residue. It does appear to be coming from the exhaust/muffler junction.
If the fuel you're seeing is coming from the engine/muffler junction, you can easily make a gasket from rubberized high-temp gasket material, easily available from any auto parts store. If it's leaking from the pressure nipple, then your fuel tubing may be a bit on the large size.
2.) The fuel tubing is relatively new and not the extra large version -- I use the same fuel line on my Saito FA-100 pressure tap with no oil/fuel leakage.
3.) At a minimum I do intend to put gasket sealing around the exhaust junction and between the 2 halves of the muffler. This will be my first OS engine that I've had to do this to out of ((3) LA .15s, (2) FP .25s, (3) FX .46s, (1) LA .65, (1) Surpass .70, (1) BX-1 1.08, and (1) FX 1.60.) The only other engines I've had to use gaskets with were a Magnum XL .15, a Magnum XL .25, a Magnum XL 1.08 and a Magnum XL 1.20.
Also, it would not really be "fuel", but oil from the exhaust stream. Any such leakage would not affect performance much,...
just make the model sloppy and dirty.
If it's raw, unburned fuel, you'll need to look more closely. Is the engine leaking from behind the drive washer? Can you feel a cool fuel spray if you hold your hand behind the propeller next to the cylinder? This is serious, and means that the engine has a bad crankshaft to case fit. You can see an oily coating on the backside of the propeller in many cases.
08-14-2002, 01:59 AM
#4
Member
My Feedback: (4)
Join Date: Apr 2002
Location: Rowlett,
TX
Posts: 93
Likes: 0
Received 0 Likes
on
0 Posts
Blubbery .50 SX
I wont claim to be an expert here, but I will relay an experience of mine.
I have a 61FX that was doing the very same thing as you describe, when I ran it on my PSP stand. I didn't think to much of it, and finished my break in runs. After removing it from the test stand, I elected to disassemble the muffler and run a bead of high temp RTV inside the muffler to seal off the "messy" leakage. Upon disassembly I noticed that the baffle/cone was installed pointing forward and actually hitting the muffler pressure tap. I went up to the LHS were I bought the engine, and we looked at another muffler and found the cone pointing aft, which I thought should be correct. I went home and turned the cone around and all is well, no leakage, with what I feel is better performance!
You might take a look at your muffler to see if yours is turned forward also. Hope this helps!
Rex Rutledge
I have a 61FX that was doing the very same thing as you describe, when I ran it on my PSP stand. I didn't think to much of it, and finished my break in runs. After removing it from the test stand, I elected to disassemble the muffler and run a bead of high temp RTV inside the muffler to seal off the "messy" leakage. Upon disassembly I noticed that the baffle/cone was installed pointing forward and actually hitting the muffler pressure tap. I went up to the LHS were I bought the engine, and we looked at another muffler and found the cone pointing aft, which I thought should be correct. I went home and turned the cone around and all is well, no leakage, with what I feel is better performance!
You might take a look at your muffler to see if yours is turned forward also. Hope this helps!
Rex Rutledge
08-15-2002, 02:21 PM
#6
Blubbery .50 SX
was installed pointing forward and actually hitting the muffler pressure tap
I'm still a little burned that I had to do this with a brand new OS SX.50. I'm also burned that the OS rep never responded to my answer to his suggestion.
08-16-2002, 01:54 PM
#7
My Feedback: (11)
Blubbery .50 SX
"I'm still a little burned that I had to do this with a brand new OS SX.50. I'm also burned that the OS rep never responded to my answer to his suggestion."
Jim,
We're sorry we can't get to posts every day. It's only been a few days since the last post. We're not able to get to the posts as quickly as we'd like. Sorry about that.
As far as leakage from the engine/muffler junction, there can be points of unevenness that allow leakage to happen. Also, all mufflers aren't always machined smoothly enough to make a tight joint.
If the engine is running very, very rich, then we'll admit that a lot of raw fuel will be blown out in the exhaust stream.
Also, extremely rich running will allow some fuel to be spit out of the caburetor intake. That's normal.
The key is when the engine's leaned and running at peak RPM. If the engine still spits fuel or emits exhaust residue, it should be examined to see where it's coming from.
We hope you find this information helpful. Should you have any further questions or concerns, please do not hesitate to contact us at this email address. (Please be sure to copy all previous emails into any future questions.)
DID YOU KNOW that our web pages now all contain FAQs? (Frequently asked questions) Please drop by and take a look! We hope you'll find the information helpful and valuable to you.
Sincerely,
Bill Baxter, Manager
Hobby Services
1610 Interstate Dr.
Champaign, IL 61822
USA
Phone: 217 398-0007
Fax: 217 398-7721
Email: [email protected]
Web: http://www.bestrc.com
Jim,
We're sorry we can't get to posts every day. It's only been a few days since the last post. We're not able to get to the posts as quickly as we'd like. Sorry about that.
As far as leakage from the engine/muffler junction, there can be points of unevenness that allow leakage to happen. Also, all mufflers aren't always machined smoothly enough to make a tight joint.
If the engine is running very, very rich, then we'll admit that a lot of raw fuel will be blown out in the exhaust stream.
Also, extremely rich running will allow some fuel to be spit out of the caburetor intake. That's normal.
The key is when the engine's leaned and running at peak RPM. If the engine still spits fuel or emits exhaust residue, it should be examined to see where it's coming from.
We hope you find this information helpful. Should you have any further questions or concerns, please do not hesitate to contact us at this email address. (Please be sure to copy all previous emails into any future questions.)
DID YOU KNOW that our web pages now all contain FAQs? (Frequently asked questions) Please drop by and take a look! We hope you'll find the information helpful and valuable to you.
Sincerely,
Bill Baxter, Manager
Hobby Services
1610 Interstate Dr.
Champaign, IL 61822
USA
Phone: 217 398-0007
Fax: 217 398-7721
Email: [email protected]
Web: http://www.bestrc.com
08-21-2002, 01:57 PM
#8
Blubbery .50 SX
As far as leakage from the engine/muffler junction, there can be points of unevenness that allow leakage to happen. Also, all mufflers aren't always machined smoothly enough to make a tight joint.
BTW, Even after using hi-temp gasket sealer on all connections on the muffler I still have some leakage. I have not tried one of my FX .46 mufflers yet but will be doing so on my next flight.
If I find that my FX .46 muffler fixes the problem can I send in the muffler that came with the SX .50 for a replacement?
