ASP 108
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I have an ASP 108 with OS 7d carb. What prop should I use and how much nitro would I need? It is the older ASP. I bench ran it with 5 nitro and a beat up 16x8 MAS prop, but didn't tach it so I don't know where I am at. I was thinking of trying a 16x6 or 17x5. I would like some advice from others who have ran or know of this motor. Thanks.
#3

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If the ASP 1.08 is the same as the older Magnum 1.08, it tends to be a tractor engine, rather than a sports car engine. We have found a 15-8 or a 16-6 is the best prop. The smaller and lower pitch props didn't turn that much faster to make up the difference.
On a sport plane, I run a 16-6. On a scale plane that I want a little faster, I run a 15-8.
On a sport plane, I run a 16-6. On a scale plane that I want a little faster, I run a 15-8.
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ORIGINAL: w8ye
15-6 is more like it.
The carb cost more than the engine to purchase?
15-6 is more like it.
The carb cost more than the engine to purchase?
Does anyone know about the nitro? Many of these motors didn't like much nitro.
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Believe it or not I had a 7M OS carb on my Mag 108.....great carb crappy engine, may it RIP.
Put the carb on a ST 90, more of everything in the power dept.. I am not a Magnum basher and have more than several but the 108 isn't much to say the least.
Put the carb on a ST 90, more of everything in the power dept.. I am not a Magnum basher and have more than several but the 108 isn't much to say the least.
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My asp 1.08 ran best on a 15-6, but I don't know how fast it turned. A 14-6 was definitely too small. Mine ran like crap, but i have since discovered that the carb is NFG. I believe a new carb would get it going well, and 5% nitro should do the trick.
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I have two of them, both with OS 7D carbs. Older one is in a Goldberg Ultimate Bipe, 12 years old now, and I run a 14x10 APC prop on it, 10% Omega fuel. It equals a friend's Ultimate with the OS 108, but we went to a 15x8 to slow it up a little for him. My second one is in a Lanier Laser 200 (kit), same set-up but I run a 15x8 on it since it is a little bigger airframe.
I have 38 glow engines, 21 in use, and the ASPs are not the best of the bunch, but are fairly reliable work horses with the OS carb. Start easily, almost never touch the needle valve, no dead sticks, good idle. OS A-3 plugs work well. And one uses a Slimline Pitts style muffler, the other a Bisson p. style. Both good.
Hope this information is of use to you.
Clair
I have 38 glow engines, 21 in use, and the ASPs are not the best of the bunch, but are fairly reliable work horses with the OS carb. Start easily, almost never touch the needle valve, no dead sticks, good idle. OS A-3 plugs work well. And one uses a Slimline Pitts style muffler, the other a Bisson p. style. Both good.
Hope this information is of use to you.
Clair
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ORIGINAL: Sport_Pilot
I think the original carb is oversized. Won't run well unless the muffler is restrictive, or use a pump or regulator. Otherwise the carb is excellent.
I think the original carb is oversized. Won't run well unless the muffler is restrictive, or use a pump or regulator. Otherwise the carb is excellent.
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Sport Pilot is right, the carb is too large. It will work if you run it with the factory muffler, which was an exact clone of the OS 61 FSR muffler (which I had several of, to compare). So, they opened up the carb to get more rpm, then when it wouldn't suck fuel, they used an undersize restrictive muffler on it to increase tank pressure. I could not richen the engine enough for safe flight on my first one, with a Slimline muffler (fairly open) and the stock carb. I put it on the bench, and it would run ok with the factory muffler. It would also run ok with the Pitts style, as long as I used the OS 7D carb, and I only lost 100 rpm in the process. So both of my ASPs use the OS carbs and run very well with Pitts style mufflers.
An interesting side note however, I tried the ASP carb on one of my Webra 120 engines, which happened to be pumped (Perry P-30), and the carb worked as well if not better than the Webra carb.
So.....live and learn, I guess.
Clair
An interesting side note however, I tried the ASP carb on one of my Webra 120 engines, which happened to be pumped (Perry P-30), and the carb worked as well if not better than the Webra carb.
So.....live and learn, I guess.
Clair
#12

My son bought a second hand SC 1.08 (same as the ASP I believe?) with a busted carb. We fitted an Enya 60 carb which was a drop in fit and the engine works perfectly. From memory I think it was giving about 8000+ on a 15x8 prop but I don't know how many revs it might have lost from the standard carb. However, it's totally reliable on zero nitro even though anyone who felt the compression would throw it away

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ORIGINAL: Sport_Pilot
I think the original carb is oversized. Won't run well unless the muffler is restrictive, or use a pump or regulator. Otherwise the carb is excellent.
I think the original carb is oversized. Won't run well unless the muffler is restrictive, or use a pump or regulator. Otherwise the carb is excellent.
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hi, i have an sc108( same motor?). Standard everything, os 8 plug, 15 x 8 graupner wide prop, running on modeltechnics bekra 16%,starts first time and idles and throttles nicely, enough to prop hang my funtana90 with power to spare.
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ORIGINAL: Sport_Pilot
I think the original carb is oversized. Won't run well unless the muffler is restrictive, or use a pump or regulator. Otherwise the carb is excellent.
I think the original carb is oversized. Won't run well unless the muffler is restrictive, or use a pump or regulator. Otherwise the carb is excellent.
-------------
Yep. I had the 1.08 Redhead of many moons ago.
I removed one tube from my Pitts muffler (can't remember the brand) and covered over the hole with aluminum roof flashing held on by six sheet metal screws and silicone glue. That took care of the muffler pressure problem entirely. Sweet running engine on 5% nitro fuel. More than that and it overheated and deadsticked continually unless an extra head gasket was used.
I had no problems with the stock carb after modifying my muffler. I wish I had kept that engine now. One flip starts were the norm.
#17

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They can make one up for you.
You need to remove your carb and measure the diameter of the shank for them. But I can tell you now that it measures. .590" and the Perry #4501 is the carb you want
Call them http://www.perrypumps.com/prod01.htm
630-858-3160 between 8:00 AM to 5:00 PM Central Standard Time
You need to remove your carb and measure the diameter of the shank for them. But I can tell you now that it measures. .590" and the Perry #4501 is the carb you want
Call them http://www.perrypumps.com/prod01.htm
630-858-3160 between 8:00 AM to 5:00 PM Central Standard Time
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hello i have the same engine with the chrome head i tuned it in the workbench and all was fine.when i put it in my h9 p47 thunderbold at 90degrees it starts to lose fuel from the carb (the first problem) and the second in the ground when you advance the throtle to full after 2 secs it overheats thing that in the workbench didnt happened.What do you believe is the overheating problem?
PS when i try to tune it richer it always dies HELP PLEASEE
#23

I have a red head ASP 1.08, been breaking it in on 5% nitro and a smallish prop, 15x6 for now. I'm going to use it in a 10lbs Lanier Laser 1/4 Scale ship. Seems to run fine on the bench with stock carb and muffler.
Chris...
Chris...
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I have the same engine in the same plane, although mine is less than ten pounds. It flies it very well, 15x8 APC as I recall. Your problems are apt to begin when you try to run it with a Pitts style muffler. You may have to plug one of the two muffler exhaust pipes, or put an OS 7D carb on it, as I did. I have a newer Series 3 ASP 108 and it has an improved carb, so if you could get that carb (or the Magnum carb, same basic engine) you would have a nice running engine.
Clair
Clair
#25
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ORIGINAL: Gizmo-RCU
Believe it or not I had a 7M OS carb on my Mag 108.....great carb crappy engine, may it RIP.
Put the carb on a ST 90, more of everything in the power dept.. I am not a Magnum basher and have more than several but the 108 isn't much to say the least.
Believe it or not I had a 7M OS carb on my Mag 108.....great carb crappy engine, may it RIP.
Put the carb on a ST 90, more of everything in the power dept.. I am not a Magnum basher and have more than several but the 108 isn't much to say the least.
Where are you fellows buying all of these crappy ASP engines? I have close to two dozen ASP/Magnum engines of various sizes and not one has had to have the carb replaced or repaired in any other way.
Jim Goad must have pulled his hair out when selling the ASP line initially. He said in the instructions for the ASP 1.08 to limit the nitro to 5% unless you installed the included head shim. Nope. Folks mounted them up, then fueled them with 10 to 15% nitro fuel and then had the audacity to complain about overheating and deadsticking. All they had to do was read the manual where it clearly explained why you shouldn't run that much nitro without adding the headshim. Then folks call them crappy.
My Sanye engines have all been good performers with one minor exception. My one Magnum FS-30 four-stroke won't idle below 3k rpm. Big deal. It is reliable in every other way. I am so pissed off and disturbed by this minor quirk that I even bought two more NIB Magnum FS-30 engines. That's a joke, son. But I did buy two more NIB engines, so I'm not too upset with them.
Ed Cregger