Club FOX!
11-06-2010, 10:28 AM
#1401
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RE: Club FOX!
I have a fox .40 BB, I was about to throw it away after a complete rebuild at the factory in Ft Smith, Ar. They had test ran it and said it was doing fine. After mounting it on a test stand, I noticed that fuel was being blown out of the head. Checked to see if the head bolts were tight, they weren't. Now it runs as sweeet as any engine I have ever owned. The power is awesome for a 40, I think I could blow away some of the Japanese engines the same size. The idle is count the rpms and top in its the screaming meemies. Also the 2 needle carb makes transistion from idle to top speed instant and not a hiccup.
11-06-2010, 04:35 PM
#1402
RE: Club FOX!
I am glad you noticed the loose head screws. That is actually way more common than people realize. Not just Fox but with all brands actually.
I recently got a nice running Irvine 61 from a guy who thought it was junk. Yes you guessed it the head bolts were loose.
I tried to give it back to him, but he wanted nothing to do with it anymore. as far as he was concerned it is a junk engine.
One needs to check the head screws every now and then as they can and do loosen up for various reasons. One way is as the engine is heat cycled (started, warmed up, and used, and then allowed to cool off) is the uneven heating of the engine causes the metal parts to expand and contract differently from each other, it can actually scour or wear the surfaces down where the head contacts the cylinder or sleeve lip on the engine. I have some examples of well used engines where you can run your fingernail on the head mating surface and feel a small lip there as the head was worn down into the cylinder lip on the engine.
One classic example is old multicylinder motorcyle engines. namely the four cylinder varieties. After a long time the head to cylinder gasket is worn or scoured down and the engine starts to leak oil at the joint first, before the head gasket eventually blows out. Honda many years ago on their 750 fours, wound up with a complex crankcase casting where the upper crankcase half and the cylinder block was cast as one unit. Honda had to do that as the engines would eat up the cylinder base gasket in a very short time frame. But in anycase, you had to go through the hassle to replace the head gasket from time to time on these air cooled engines.
I recently got a nice running Irvine 61 from a guy who thought it was junk. Yes you guessed it the head bolts were loose.
I tried to give it back to him, but he wanted nothing to do with it anymore. as far as he was concerned it is a junk engine.
One needs to check the head screws every now and then as they can and do loosen up for various reasons. One way is as the engine is heat cycled (started, warmed up, and used, and then allowed to cool off) is the uneven heating of the engine causes the metal parts to expand and contract differently from each other, it can actually scour or wear the surfaces down where the head contacts the cylinder or sleeve lip on the engine. I have some examples of well used engines where you can run your fingernail on the head mating surface and feel a small lip there as the head was worn down into the cylinder lip on the engine.
One classic example is old multicylinder motorcyle engines. namely the four cylinder varieties. After a long time the head to cylinder gasket is worn or scoured down and the engine starts to leak oil at the joint first, before the head gasket eventually blows out. Honda many years ago on their 750 fours, wound up with a complex crankcase casting where the upper crankcase half and the cylinder block was cast as one unit. Honda had to do that as the engines would eat up the cylinder base gasket in a very short time frame. But in anycase, you had to go through the hassle to replace the head gasket from time to time on these air cooled engines.
11-06-2010, 05:22 PM
#1403
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RE: Club FOX!
Earl, this Irvine Q-72 had the head bolts come loose after its first half season of flying first on a Tower 60 Trainer then an Ultra Stik 60. It has never come loose since. It lost power in flight and was so hot the head smoked but luckily the head was not burned black. The original Q-72 muffler was broken when the Earth failed to cooperate on a landing. This muffler is a MVVS 3255 Quiet Muffler. The MVVS mufflers are very light.
11-06-2010, 06:04 PM
#1404
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RE: Club FOX!
ORIGINAL: Konrad
Well, if it has muffler tabs it is a late 70's or later. If the carb look like Earls then she is from the late 70's or earlier. If the carb barrel moves back and forth (in and out) she has the Mk X carb and is from the early 80s or newer.
Well, if it has muffler tabs it is a late 70's or later. If the carb look like Earls then she is from the late 70's or earlier. If the carb barrel moves back and forth (in and out) she has the Mk X carb and is from the early 80s or newer.
11-06-2010, 06:34 PM
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RE: Club FOX!
The muffler would have tabs, but does the case have a set to accept the muffler. Does the case have a bead blast finish. If so then it is one of the later models. Both the butterfly carb Earl is showing and the Mk X carb have rotating throttle barrels. But with the Mk X carb the barrel moves in and out as it is rotated.
All the best,
Konrad
All the best,
Konrad
11-06-2010, 08:20 PM
#1406
RE: Club FOX!
Ok now as I remember it, the first .78's, circa 1971, may have had the three needle butterfly carb and used a rotating exhaust baffle for better idling, no muffler mounting tabs, a dual plug head, and a shiny, sorta polished crankcase. I have a extra three needle carb in my old engine box, so I might have swapped it out on my engine example. But I do not remember anymore. Anyway the 1971 ad shows the three needle carb on the engine.
Then Fox switched to the two needle butterfly carb like on my engine example.
later they went with the single glow plug head.
Then came the MK-X carb two needle carb.
Then muffler mounting tabs. I am not sure if they had a flanged muffler and kept the rotating exhaust baffle or not at this point.
Fox may have made some engines without the rotating exhaust baffle, but with aluminum plugs pressed into the outer holes.
Then they dropped the rotating exhaust baffle and went with just using a muffler on the engine.
The final versions were sandblasted (not really sand, crushed walnut shells?) to give them the darker gray dull appearance.
it is possible that during this evolution of the engines that the port sizes and port timing could have changed as well as the compression ratios. But I have no way of telling myself.
Now the first engine of the series that used this huge heavy duty crankcase was the .74 engine. Later after the FAI and AMA ruled to limit F3A pattern to 10cc, Fox was stuck. So they came out with a .60 engine using the same crankcase, both the early .60 and .74 used steel needle bearing connecting rods. Fox also entertained the idea of putting out a .90 version engine for the boating community, but apparently it never went into production.
A Fox .78 made from circa 1981 onwards;
Then Fox switched to the two needle butterfly carb like on my engine example.
later they went with the single glow plug head.
Then came the MK-X carb two needle carb.
Then muffler mounting tabs. I am not sure if they had a flanged muffler and kept the rotating exhaust baffle or not at this point.
Fox may have made some engines without the rotating exhaust baffle, but with aluminum plugs pressed into the outer holes.
Then they dropped the rotating exhaust baffle and went with just using a muffler on the engine.
The final versions were sandblasted (not really sand, crushed walnut shells?) to give them the darker gray dull appearance.
it is possible that during this evolution of the engines that the port sizes and port timing could have changed as well as the compression ratios. But I have no way of telling myself.
Now the first engine of the series that used this huge heavy duty crankcase was the .74 engine. Later after the FAI and AMA ruled to limit F3A pattern to 10cc, Fox was stuck. So they came out with a .60 engine using the same crankcase, both the early .60 and .74 used steel needle bearing connecting rods. Fox also entertained the idea of putting out a .90 version engine for the boating community, but apparently it never went into production.
A Fox .78 made from circa 1981 onwards;
11-06-2010, 09:09 PM
#1407
RE: Club FOX!
Now then the old .74 engine, the first of the series used a early version butterly carb on it. Note that in the second pic, that Fox had thoughtfully provided a place to drill and tap for a pressure fitting just below the carb mount.
11-06-2010, 10:48 PM
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RE: Club FOX!
ORIGINAL: earlwb
I am glad you noticed the loose head screws. That is actually way more common than people realize. Not just Fox but with all brands actually.
I recently got a nice running Irvine 61 from a guy who thought it was junk. Yes you guessed it the head bolts were loose.
I tried to give it back to him, but he wanted nothing to do with it anymore. as far as he was concerned it is a junk engine.
One needs to check the head screws every now and then as they can and do loosen up for various reasons. One way is as the engine is heat cycled (started, warmed up, and used, and then allowed to cool off) is the uneven heating of the engine causes the metal parts to expand and contract differently from each other, it can actually scour or wear the surfaces down where the head contacts the cylinder or sleeve lip on the engine. I have some examples of well used engines where you can run your fingernail on the head mating surface and feel a small lip there as the head was worn down into the cylinder lip on the engine.
One classic example is old multicylinder motorcyle engines. namely the four cylinder varieties. After a long time the head to cylinder gasket is worn or scoured down and the engine starts to leak oil at the joint first, before the head gasket eventually blows out. Honda many years ago on their 750 fours, wound up with a complex crankcase casting where the upper crankcase half and the cylinder block was cast as one unit. Honda had to do that as the engines would eat up the cylinder base gasket in a very short time frame. But in anycase, you had to go through the hassle to replace the head gasket from time to time on these air cooled engines.
I am glad you noticed the loose head screws. That is actually way more common than people realize. Not just Fox but with all brands actually.
I recently got a nice running Irvine 61 from a guy who thought it was junk. Yes you guessed it the head bolts were loose.
I tried to give it back to him, but he wanted nothing to do with it anymore. as far as he was concerned it is a junk engine.
One needs to check the head screws every now and then as they can and do loosen up for various reasons. One way is as the engine is heat cycled (started, warmed up, and used, and then allowed to cool off) is the uneven heating of the engine causes the metal parts to expand and contract differently from each other, it can actually scour or wear the surfaces down where the head contacts the cylinder or sleeve lip on the engine. I have some examples of well used engines where you can run your fingernail on the head mating surface and feel a small lip there as the head was worn down into the cylinder lip on the engine.
One classic example is old multicylinder motorcyle engines. namely the four cylinder varieties. After a long time the head to cylinder gasket is worn or scoured down and the engine starts to leak oil at the joint first, before the head gasket eventually blows out. Honda many years ago on their 750 fours, wound up with a complex crankcase casting where the upper crankcase half and the cylinder block was cast as one unit. Honda had to do that as the engines would eat up the cylinder base gasket in a very short time frame. But in anycase, you had to go through the hassle to replace the head gasket from time to time on these air cooled engines.
11-06-2010, 11:47 PM
#1409
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RE: Club FOX!
It is my experience that the head bolts rarely if ever stretch on our toy engines. What I see happening it that the cylinder mounting flange expands collapsing the retention shoulder in the case. When the engine cools down the bolts appear to have loosen, when in fact the cylinder is now a little deeper in the case. Most ABC set ups with a brass cylinder exhibit this phenomenon to an even greater extent as most brass alloys have a higher coefficient of expansion than steel.
I wrote a dissertation on this. I'll need to find it. If I do I'll post it here.
I have measured "stretched" bolts and can say they were the same length prior to installation.
I wrote a dissertation on this. I'll need to find it. If I do I'll post it here.
I have measured "stretched" bolts and can say they were the same length prior to installation.
11-07-2010, 12:06 AM
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RE: Club FOX!
Earl,
Nice photo of the post '81' 0.78 it offers a much better description than my words!
I also like the time crankcase pressure port. Fox did this a lot.
All the best
Nice photo of the post '81' 0.78 it offers a much better description than my words!
I also like the time crankcase pressure port. Fox did this a lot.
All the best
11-07-2010, 10:33 AM
#1411
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RE: Club FOX!
ORIGINAL: earlwb
Ok now as I remember it, the first .78's, circa 1971, may have had the three needle butterfly carb and used a rotating exhaust baffle for better idling, no muffler mounting tabs, a dual plug head, and a shiny, sorta polished crankcase. I have a extra three needle carb in my old engine box, so I might have swapped it out on my engine example. But I do not remember anymore. Anyway the 1971 ad shows the three needle carb on the engine.
Then Fox switched to the two needle butterfly carb like on my engine example.
later they went with the single glow plug head.
Then came the MK-X carb two needle carb.
Then muffler mounting tabs. I am not sure if they had a flanged muffler and kept the rotating exhaust baffle or not at this point.
Fox may have made some engines without the rotating exhaust baffle, but with aluminum plugs pressed into the outer holes.
Then they dropped the rotating exhaust baffle and went with just using a muffler on the engine.
The final versions were sandblasted (not really sand, crushed walnut shells?) to give them the darker gray dull appearance.
it is possible that during this evolution of the engines that the port sizes and port timing could have changed as well as the compression ratios. But I have no way of telling myself.
Now the first engine of the series that used this huge heavy duty crankcase was the .74 engine. Later after the FAI and AMA ruled to limit F3A pattern to 10cc, Fox was stuck. So they came out with a .60 engine using the same crankcase, both the early .60 and .74 used steel needle bearing connecting rods. Fox also entertained the idea of putting out a .90 version engine for the boating community, but apparently it never went into production.
[img][/img]
[img][/img]
A Fox .78 made from circa 1981 onwards;
[img][/img]
Ok now as I remember it, the first .78's, circa 1971, may have had the three needle butterfly carb and used a rotating exhaust baffle for better idling, no muffler mounting tabs, a dual plug head, and a shiny, sorta polished crankcase. I have a extra three needle carb in my old engine box, so I might have swapped it out on my engine example. But I do not remember anymore. Anyway the 1971 ad shows the three needle carb on the engine.
Then Fox switched to the two needle butterfly carb like on my engine example.
later they went with the single glow plug head.
Then came the MK-X carb two needle carb.
Then muffler mounting tabs. I am not sure if they had a flanged muffler and kept the rotating exhaust baffle or not at this point.
Fox may have made some engines without the rotating exhaust baffle, but with aluminum plugs pressed into the outer holes.
Then they dropped the rotating exhaust baffle and went with just using a muffler on the engine.
The final versions were sandblasted (not really sand, crushed walnut shells?) to give them the darker gray dull appearance.
it is possible that during this evolution of the engines that the port sizes and port timing could have changed as well as the compression ratios. But I have no way of telling myself.
Now the first engine of the series that used this huge heavy duty crankcase was the .74 engine. Later after the FAI and AMA ruled to limit F3A pattern to 10cc, Fox was stuck. So they came out with a .60 engine using the same crankcase, both the early .60 and .74 used steel needle bearing connecting rods. Fox also entertained the idea of putting out a .90 version engine for the boating community, but apparently it never went into production.
[img][/img]
[img][/img]
A Fox .78 made from circa 1981 onwards;
[img][/img]
11-07-2010, 10:54 AM
#1412
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RE: Club FOX!
Then I think you have one of the nicest 0.78's that Duke made. She likes lower nitro than some of the previous models. She also is sporting the Mk X "C" carb with a 0.330 diameter choke. This is a very nice and flexible carb. The MAN article has the power plots for that engine.
All the best,
Konrad
All the best,
Konrad
11-07-2010, 05:15 PM
#1413
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RE: Club FOX!
To me, once you learned to adjust it properly, the only gripe I had about the butterfly carb was the cast-in-place tapered fuel fitting. And that was easy to fix with a file and a lock washer (stopped it from spitting off the fuel line).
Ed Cregger
Ed Cregger
11-07-2010, 05:43 PM
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RE: Club FOX!
ORIGINAL: NM2K
To me, once you learned to adjust it properly, the only gripe I had about the butterfly carb was the cast-in-place tapered fuel fitting. And that was easy to fix with a file and a lock washer (stopped it from spitting off the fuel line).
Ed Cregger
To me, once you learned to adjust it properly, the only gripe I had about the butterfly carb was the cast-in-place tapered fuel fitting. And that was easy to fix with a file and a lock washer (stopped it from spitting off the fuel line).
Ed Cregger
By the way Duke replaced all the butterfly carbs on my 1.20 twins with the Mk X every time I sent them in for service.
All the best,
Konrad
11-07-2010, 05:51 PM
#1415
RE: Club FOX!
The real trick to using the cast in fuel inlet on the Fox butterfly carb is to use a short length of black neoprine tubing to connect the fuel line with. You simply run the silicone fuel tubing like normal stop a little short with it, and using a splice tube run a short piece of neoprine tubing to the carb. The neoprine tubing sort of glues itself to the fuel inlet, and doesn't slide off in useage. When Fox designed the carbs, we didn't have silicone fuel tubing yet. Just the black neoprine tubing and that semi-flexible clear plastic tubing stuff. Anyway the black neoprine tubing works like magic, it just stays right on the tapered cast in fuel inlet without popping off.
Actually I think for a few of years Fox made the .78 without the two side mounting tabs, and he drilled and tapped the two screw holes above and below the exhaust port. At that time, the mufflers had two side notches to clear the rotating exhaust baffle. Then around 1981 he started using the two side mounting tabs for the muffler.
Oh yeah, the extra small neoprine tubing also worked on the COX TeeDee engines if you drilled out the timed pressure port just below the intake venturi on the right side of the engines. When Cox had those engines first designed we didn't have fancy silicone tubing yet either.
Actually I think for a few of years Fox made the .78 without the two side mounting tabs, and he drilled and tapped the two screw holes above and below the exhaust port. At that time, the mufflers had two side notches to clear the rotating exhaust baffle. Then around 1981 he started using the two side mounting tabs for the muffler.
Oh yeah, the extra small neoprine tubing also worked on the COX TeeDee engines if you drilled out the timed pressure port just below the intake venturi on the right side of the engines. When Cox had those engines first designed we didn't have fancy silicone tubing yet either.
11-07-2010, 05:53 PM
#1416
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RE: Club FOX!
ORIGINAL: Konrad
Then I think you have one of the nicest 0.78's that Duke made. She likes lower nitro than some of the previous models. She also is sporting the Mk X ''C'' carb with a 0.330 diameter choke. This is a very nice and flexible carb. The MAN article has the power plots for that engine.
All the best,
Konrad
Then I think you have one of the nicest 0.78's that Duke made. She likes lower nitro than some of the previous models. She also is sporting the Mk X ''C'' carb with a 0.330 diameter choke. This is a very nice and flexible carb. The MAN article has the power plots for that engine.
All the best,
Konrad
11-07-2010, 06:17 PM
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RE: Club FOX!
Yes, the Mk X barrel moves in and out as the barrel is rotated. There is a good discussion on carbs well there was here.
http://www.rcuniverse.com/forum/m_10015277/tm.htm
I for the life of me don't understand why it was locked. I even had a few (lots) nice things to say about the OS 4B carb which were deleted.
The Fox Mk X works much like the Webra TN carb in theory.
All the best,
Konrad
http://www.rcuniverse.com/forum/m_10015277/tm.htm
I for the life of me don't understand why it was locked. I even had a few (lots) nice things to say about the OS 4B carb which were deleted.
The Fox Mk X works much like the Webra TN carb in theory.
All the best,
Konrad
11-07-2010, 06:36 PM
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RE: Club FOX!
ORIGINAL: Konrad
Yes, the Mk X barrel moves in and out as the barrel is rotated. There is a good discussion on carbs well there was here.
http://www.rcuniverse.com/forum/m_10015277/tm.htm
I for the life of me don't understand why is was locked. I even had a few (lots) nice this to say about the OS 4B carb which were deleted.
The Fox Mk X works much like the Webra TN carb in theory.
All the best,
Konrad
Yes, the Mk X barrel moves in and out as the barrel is rotated. There is a good discussion on carbs well there was here.
http://www.rcuniverse.com/forum/m_10015277/tm.htm
I for the life of me don't understand why is was locked. I even had a few (lots) nice this to say about the OS 4B carb which were deleted.
The Fox Mk X works much like the Webra TN carb in theory.
All the best,
Konrad
11-07-2010, 06:50 PM
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RE: Club FOX!
Idle bars are fine. In fact they are preferred with the baffled engine. I suspect the pre chambered glow plug might also work just fine. I had never used them in my day.
As for props that is as much dependent on the airframe as anything else.
When I get back home I'll see if I can find that MAN article and l'll let you know where the torque and HP peaks are.
All the best,
Konrad
As for props that is as much dependent on the airframe as anything else.
When I get back home I'll see if I can find that MAN article and l'll let you know where the torque and HP peaks are.
All the best,
Konrad
11-07-2010, 07:11 PM
#1420
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RE: Club FOX!
ORIGINAL: Konrad
Idle bars are fine. In fact they are preferred with the baffled engine. I suspect the pre chambered glow plug might also work just fine. I had never used them in my day.
As for props that is as much dependent on the airframe as anything else.
When I get back home I'll see if I can find that MAN article and l'll let you know where the torque and HP peaks are.
All the best,
Konrad
Idle bars are fine. In fact they are preferred with the baffled engine. I suspect the pre chambered glow plug might also work just fine. I had never used them in my day.
As for props that is as much dependent on the airframe as anything else.
When I get back home I'll see if I can find that MAN article and l'll let you know where the torque and HP peaks are.
All the best,
Konrad
11-07-2010, 07:17 PM
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RE: Club FOX!
Please don't hold your breath. I'm often the victim of a clean up. The article might very well have been thrown out. But for rough numbers I'm sure what Earlwb showed for the earlier models will work fine. Again it all depends on how the engine, prop and airframe all interact. So you will need to select the best prop empirically.
All the best,
Konrad
All the best,
Konrad
11-07-2010, 07:32 PM
#1422
RE: Club FOX!
ORIGINAL: 93octane
Ok....Thanks...also whats agood prop range for this model 78?....Globee idle bar plug OK?? Really great info in Dukes engines here!
Ok....Thanks...also whats agood prop range for this model 78?....Globee idle bar plug OK?? Really great info in Dukes engines here!
For example a Antique Free flight plane setup for RC might work well with a larger prop and low RPMs which simulates running a antique spark ignition gasoline engine. For example a 8 foot Playboy free flight RC plane. Or like I did many years ago, with a SIG Fokker Biplane kit. I ran a larger prop as the plane tended to float around at low speed anyway. Something around a 12x6 to a 13x6 might be the way to go on a Sig Astro Hog for example. I think Fox advertised towards the end of the engine's production where it was using a 11x8 prop too. It turned the 11x8 prop faster than the venerable Fox Eagle 1 could.
But many planes could run the larger props, it just depends on the speeds needed to fly them OK.
If that is what you have a Glow Bee idle bar plug is fine. But we normally ran Fox RC long plugs on them.
Many of these engines came really tight from the factory, so you may need a extended break in or run in with them. Don't try for all out power until you have run them in good first. Sometimes they tend to be really slow to break in. Don't run the 20% nitro fuels like Missile Mist until you have run in the engine really good.
11-07-2010, 07:43 PM
#1423
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RE: Club FOX!
ORIGINAL: earlwb
A 12x6, 13x6, 14x6, 15x6 and 16x6 prop works. Variations depending on pitch as well. It really depends on the airplane you are wanting to use it in.
For example a Antique Free flight plane setup for RC might work well with a larger prop and low RPMs which simulates running a antique spark ignition gasoline engine. For example a 8 foot Playboy free flight RC plane. Or like I did many years ago, with a SIG Fokker Biplane kit. I ran a larger prop as the plane tended to float around at low speed anyway. Something around a 12x6 to a 13x6 might be the way to go on a Sig Astro Hog for example. I think Fox advertised towards the end of the engine's production where it was using a 11x8 prop too. It turned the 11x8 prop faster than the venerable Fox Eagle 1 could.
But many planes could run the larger props, it just depends on the speeds needed to fly them OK.
If that is what you have a Glow Bee idle bar plug is fine. But we normally ran Fox RC long plugs on them.
Many of these engines came really tight from the factory, so you may need a extended break in or run in with them. Don't try for all out power until you have run them in good first. Sometimes they tend to be really slow to break in.
[img][/img]
ORIGINAL: 93octane
Ok....Thanks...also whats agood prop range for this model 78?....Globee idle bar plug OK?? Really great info in Dukes engines here!
Ok....Thanks...also whats agood prop range for this model 78?....Globee idle bar plug OK?? Really great info in Dukes engines here!
For example a Antique Free flight plane setup for RC might work well with a larger prop and low RPMs which simulates running a antique spark ignition gasoline engine. For example a 8 foot Playboy free flight RC plane. Or like I did many years ago, with a SIG Fokker Biplane kit. I ran a larger prop as the plane tended to float around at low speed anyway. Something around a 12x6 to a 13x6 might be the way to go on a Sig Astro Hog for example. I think Fox advertised towards the end of the engine's production where it was using a 11x8 prop too. It turned the 11x8 prop faster than the venerable Fox Eagle 1 could.
But many planes could run the larger props, it just depends on the speeds needed to fly them OK.
If that is what you have a Glow Bee idle bar plug is fine. But we normally ran Fox RC long plugs on them.
Many of these engines came really tight from the factory, so you may need a extended break in or run in with them. Don't try for all out power until you have run them in good first. Sometimes they tend to be really slow to break in.
[img][/img]
11-07-2010, 07:46 PM
#1424
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RE: Club FOX!
The 70's model of Foxes sometimes were real problematic. In that Duke often setup the clearance between crank to crankcase seal too small (tight). He did offer some lapping compounds to open this up. But you needed to know what you were doing. Again I think I show a crankshaft with this burned seal damage. The 80's engines weren't so problematic as he did set them up a little loose in the crank case. Please please do use fuel with 20% oil content and that the oil be 100% castor. This should be the fuel you use for breaking in just about any engine, from the small 2.5cc two cycle to the 30 cc four cycle no matter who the OEM is.
http://www.rcuniverse.com/forum/fb.asp?m=9990878
All the best,
Konrad
http://www.rcuniverse.com/forum/fb.asp?m=9990878
All the best,
Konrad
11-07-2010, 07:55 PM
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RE: Club FOX!
ORIGINAL: Konrad
The 70's model of Foxes sometimes were real problematic. In that Duke often setup the clearance between crank to crankcase seal too small (tight). He did offer some lapping compounds to open this up. But you needed to know what you were doing. Again I think I show a crankshaft with this burned seal damage. The 80's engines weren't so problematic as he did set them up a little loose in the crank case. Please please do use fuel with 20% oil content and that the oil be 100% castor. This should be the fuel you use for breaking in just about any engine, from the small 2.5cc two cycle to the 30 cc four cycle no matter who the OEM is.
All the best,
Konrad
The 70's model of Foxes sometimes were real problematic. In that Duke often setup the clearance between crank to crankcase seal too small (tight). He did offer some lapping compounds to open this up. But you needed to know what you were doing. Again I think I show a crankshaft with this burned seal damage. The 80's engines weren't so problematic as he did set them up a little loose in the crank case. Please please do use fuel with 20% oil content and that the oil be 100% castor. This should be the fuel you use for breaking in just about any engine, from the small 2.5cc two cycle to the 30 cc four cycle no matter who the OEM is.
All the best,
Konrad