ASP FS52 Won't Start
12-17-2020, 11:02 AM
#1
ASP FS52 Won't Start
Hello,
I'm entirely new to glow engines and have a lot of questions to get through. I have asecond third hand ASP .52 four stroke that I got for free from a fella who partially disassembled it and let it rust; I since cleaned it up and put it back together and it has run once (swinging an APC 12x6) but it has issues. Running brand new 5% nitro, 18% oil.
1) I've cleaned the carburetor twice, checked the lines, valves, glow plug, glow igniter and wasted more fuel priming and turning over the engine than actually running it. Where have I gone wrong? The high speed needle is set at 2-1/2 turns and draws fuel easy when priming but it only thinks about popping off when I've warmed up the cylinder with a heat gun. It ran once before after heating it but I have no idea how I got it to run since it won't do it twice even with a better glow ignitor. (Plug is a new SIG four stroke.) The plug definitely wants to ignite fuel when a couple drops is squirted into the plug hole.
2) How many turns should the low speed needle be set to for initial set up?
3) The throttle valve seems to close completely (to the point where it sucks liquid) when set to idle, where should it be closing?
4) When the throttle valve is wide open (ignitor or not) the engine turns over freely (compression feels good) but with the ignitor on nearing 1/4 or closed it will get tight on me like its kicking back but not making any smoke or noise. Is it igniting fuel vapor soon and not not doing anything more than wasting my time or is it starting to hydro lock? This odd phenomena taught me propellers are sharp and to wear a leather glove when turning over an engine.
5) What do the experienced glow heads recommend for fuel proofing? 5min epoxy for the engine bay and hardened alkyd enamel paint?
Like I said, I'm brand new to nitro. I hope to get this SIG Kadet Senior kit flying in more than just my dreams before long although I do have an electric motor that would work Justin Case the ASP is a lost cause.
I'm entirely new to glow engines and have a lot of questions to get through. I have a
1) I've cleaned the carburetor twice, checked the lines, valves, glow plug, glow igniter and wasted more fuel priming and turning over the engine than actually running it. Where have I gone wrong? The high speed needle is set at 2-1/2 turns and draws fuel easy when priming but it only thinks about popping off when I've warmed up the cylinder with a heat gun. It ran once before after heating it but I have no idea how I got it to run since it won't do it twice even with a better glow ignitor. (Plug is a new SIG four stroke.) The plug definitely wants to ignite fuel when a couple drops is squirted into the plug hole.
2) How many turns should the low speed needle be set to for initial set up?
3) The throttle valve seems to close completely (to the point where it sucks liquid) when set to idle, where should it be closing?
4) When the throttle valve is wide open (ignitor or not) the engine turns over freely (compression feels good) but with the ignitor on nearing 1/4 or closed it will get tight on me like its kicking back but not making any smoke or noise. Is it igniting fuel vapor soon and not not doing anything more than wasting my time or is it starting to hydro lock? This odd phenomena taught me propellers are sharp and to wear a leather glove when turning over an engine.
5) What do the experienced glow heads recommend for fuel proofing? 5min epoxy for the engine bay and hardened alkyd enamel paint?
Like I said, I'm brand new to nitro. I hope to get this SIG Kadet Senior kit flying in more than just my dreams before long although I do have an electric motor that would work Justin Case the ASP is a lost cause.
12-17-2020, 01:46 PM
#2
It's hard to say exactly what's wrong without being able to handle the engine first hand but here are a couple ideas:
Start by opening the high speed needle a bit more. It should still run if overly rich. Low speed needle is not critical until you actually get it running.
If still no luck check the camshaft timing. You mentioned that the engine had been disassembled and the timing might not have been reset properly.
You mentioned kick back at low throttle settings but not at high settings. This could point to an overly lean high speed mixture so opening the valve to maybe 4 turns many make a difference as I mentioned initially.
Others here may have suggestions too.
You might try posting your question at RC Groups as well as this site. There is more daily action there.
Start by opening the high speed needle a bit more. It should still run if overly rich. Low speed needle is not critical until you actually get it running.
If still no luck check the camshaft timing. You mentioned that the engine had been disassembled and the timing might not have been reset properly.
You mentioned kick back at low throttle settings but not at high settings. This could point to an overly lean high speed mixture so opening the valve to maybe 4 turns many make a difference as I mentioned initially.
Others here may have suggestions too.
You might try posting your question at RC Groups as well as this site. There is more daily action there.
12-18-2020, 12:25 AM
#4
I know the cam timing on ASP/Magnum engines is a whole can of worms; I have the timing mark set in-line with the pushrods for now which it did run once but I have yet to try starting with timing at 6:00. Without the manual I went with the "that looks about right" approach which may or may not have been right 
.
.
12-19-2020, 07:57 AM
#5
Junior Member
I have a asp fs 61, compression is weak, but that's normal for this asp, nice engine for 120euros brand new few years ago.
Here we use only 15% nitro for four stroke, 5% is may be not that much in your case.
I use 4T os plug, never had any problem on my 3 4T engines.
If you have a kick back, looks like there is too much fuel or the cam is not right. To check that quickly, without the plug, put a small rod in the cylinder, find where the piston is at the top and check if the 2 valves are close. That's not precise but you don't need to be an expert in engine to do that.
And for best result when you struggle with an unknow engine, use a starter not too torquy, it saves your time, your arm
and the rod if you insist too much full of fuel.
Here we use only 15% nitro for four stroke, 5% is may be not that much in your case.
I use 4T os plug, never had any problem on my 3 4T engines.
If you have a kick back, looks like there is too much fuel or the cam is not right. To check that quickly, without the plug, put a small rod in the cylinder, find where the piston is at the top and check if the 2 valves are close. That's not precise but you don't need to be an expert in engine to do that.
And for best result when you struggle with an unknow engine, use a starter not too torquy, it saves your time, your arm
and the rod if you insist too much full of fuel.
12-19-2020, 10:12 AM
#6
I have a asp fs 61, compression is weak, but that's normal for this asp, nice engine for 120euros brand new few years ago.
Here we use only 15% nitro for four stroke, 5% is may be not that much in your case.
I use 4T os plug, never had any problem on my 3 4T engines.
If you have a kick back, looks like there is too much fuel or the cam is not right. To check that quickly, without the plug, put a small rod in the cylinder, find where the piston is at the top and check if the 2 valves are close. That's not precise but you don't need to be an expert in engine to do that.
And for best result when you struggle with an unknow engine, use a starter not too torquy, it saves your time, your arm and the rod if you insist too much full of fuel.
Here we use only 15% nitro for four stroke, 5% is may be not that much in your case.
I use 4T os plug, never had any problem on my 3 4T engines.
If you have a kick back, looks like there is too much fuel or the cam is not right. To check that quickly, without the plug, put a small rod in the cylinder, find where the piston is at the top and check if the 2 valves are close. That's not precise but you don't need to be an expert in engine to do that.
And for best result when you struggle with an unknow engine, use a starter not too torquy, it saves your time, your arm
and the rod if you insist too much full of fuel.