Saito FG-20 or 21
#276
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RE: Saito FG-20 or 21
Hi Guys,
Please don't tell me I have all this to look forward to with my Saito Fg-36 (which cost even more than the 20). I purchased a Hanger P-47 at a local flea market and cut the fire wall back so the engine would fit. But every time I read something about the FG-20 my heart starts to bound and my hair stars to fall out. Good thing I held on to a used FA 220. Sorry the picture below is the same model it just isn't mine.
Please don't tell me I have all this to look forward to with my Saito Fg-36 (which cost even more than the 20). I purchased a Hanger P-47 at a local flea market and cut the fire wall back so the engine would fit. But every time I read something about the FG-20 my heart starts to bound and my hair stars to fall out. Good thing I held on to a used FA 220. Sorry the picture below is the same model it just isn't mine.
#277
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RE: Saito FG-20 or 21
I don't think there have been bad reports about the FG 36. It has a Walbro/Saito carb on it which I believe is better that the Saito pump. Definitely put it on a test bench first when breaking it in. Make sure it runs smoothly before mounting it in something you value.
#279
RE: Saito FG-20 or 21
A solution to FG-20 pump
Many people are complaining FG-20’s pump can not deliver sufficient pressure
for high speed.
The reason is the structure of the pump (position of oil passage in oil chamber)
can not pass the air out easily.(Pump can not create sufficient pressure when air
exist in side)
The solution is :
1.Start engine at low speed.
2.Turn the engine (or airplane) till full speed needle point to up right 90 degree and backward 10 degree. And keep that position for 20 second.(all the air will escape
out of pump.
If you do it right, FG-20 will run a Master 15x6 higher than 9300rpm. But I just hate to run a new Saito above 9000rpm.
Many people are complaining FG-20’s pump can not deliver sufficient pressure
for high speed.
The reason is the structure of the pump (position of oil passage in oil chamber)
can not pass the air out easily.(Pump can not create sufficient pressure when air
exist in side)
The solution is :
1.Start engine at low speed.
2.Turn the engine (or airplane) till full speed needle point to up right 90 degree and backward 10 degree. And keep that position for 20 second.(all the air will escape
out of pump.
If you do it right, FG-20 will run a Master 15x6 higher than 9300rpm. But I just hate to run a new Saito above 9000rpm.
#280
Thread Starter
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RE: Saito FG-20 or 21
ORIGINAL: hyltaiwan
A solution to FG-20 pump
Many people are complaining FG-20’s pump can not deliver sufficient pressure
for high speed.
The reason is the structure of the pump (position of oil passage in oil chamber)
can not pass the air out easily.(Pump can not create sufficient pressure when air
exist in side)
The solution is :
1.Start engine at low speed.
2.Turn the engine (or airplane) till full speed needle point to up right 90 degree and backward 10 degree. And keep that position for 20 second.(all the air will escape
out of pump.
If you do it right, FG-20 will run a Master 15x6 higher than 9300rpm. But I just hate to run a new Saito above 9000rpm.
A solution to FG-20 pump
Many people are complaining FG-20’s pump can not deliver sufficient pressure
for high speed.
The reason is the structure of the pump (position of oil passage in oil chamber)
can not pass the air out easily.(Pump can not create sufficient pressure when air
exist in side)
The solution is :
1.Start engine at low speed.
2.Turn the engine (or airplane) till full speed needle point to up right 90 degree and backward 10 degree. And keep that position for 20 second.(all the air will escape
out of pump.
If you do it right, FG-20 will run a Master 15x6 higher than 9300rpm. But I just hate to run a new Saito above 9000rpm.
#281
Senior Member
RE: Saito FG-20 or 21
ORIGINAL: mmt33
After 3 returns, I am done with this engine and Horizon hobby, anybody wants it $250 shipping included, PM me
After 3 returns, I am done with this engine and Horizon hobby, anybody wants it $250 shipping included, PM me
BCCHI
#282
Senior Member
RE: Saito FG-20 or 21
If you are running the Rim Fire plug in your Saito 20 make sure the contact spring in the plug cap is down to make contact with the top of the spark plug. If not y ou could have a RFI problem.Make good range checks before you fly.I have not seen the Saito plug cap but if they use a spring maybe it can be pulled down a little ,if you pull it out I did not say to do this.
It sounds like the ignition is crapping out at high RPM. Six volts may help but may not be a cure all.Some will send us one some day and TKG will figure it out. If we get one we may learn a lot of things. But I bet we can make it run. I guess we will have to fly it to find out for sure. This engine should fly a old Road Runner OKI.
BCCHI
It sounds like the ignition is crapping out at high RPM. Six volts may help but may not be a cure all.Some will send us one some day and TKG will figure it out. If we get one we may learn a lot of things. But I bet we can make it run. I guess we will have to fly it to find out for sure. This engine should fly a old Road Runner OKI.
BCCHI
#283
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RE: Saito FG-20 or 21
Also, what Saillfish did not tell you is that his first flight on the engine went without symptoms. On the second flight, the engine went right back to loading up in the mid range. We also noted that the engine was running fairly hot. Heat may be a problem as most 2 stroke gassers have a phenolic (or other material) standoff to keep heat from transferring to the carb. However, the 36 does not to seem to have carb issues in the same configuration.
I might add that the engine in his plane is side mounted protruding to the right side of the plane. In level flight the carb would be slightly on the top side (I think, I may be backwards) and inverted, the carb is on the bottom side. His tanks centerline is mounted only slightly lower than the engine. When he would place the plane into a neutral inverted flight or apply a negative G load, level or inverted, the engine would richen and sputter!
It might make some sense that when the plane is inverted, the tanks centerline is slightly above the engine and causes a flow change, but this does not explain the fact that in level flight, anytime down elevator is applied, the engine loads and sputters. If the carb was functioning properly, there should be no rpm changes despite the position of the plane/tank.
The carb seems to be sensitive to positional changes. I would like to think that Saito is working on a better carb design for this engine and that it might be available in the near future. Patience may prevail in this situation. Sending the engines back for repair seems to be a waste of time. The engines will run well on a test stand giving the impression that nothing is wrong. It's only when the engine is installed and airborne does it become problematic. I know I won't be buying one anytime soon!
I might add that the engine in his plane is side mounted protruding to the right side of the plane. In level flight the carb would be slightly on the top side (I think, I may be backwards) and inverted, the carb is on the bottom side. His tanks centerline is mounted only slightly lower than the engine. When he would place the plane into a neutral inverted flight or apply a negative G load, level or inverted, the engine would richen and sputter!
It might make some sense that when the plane is inverted, the tanks centerline is slightly above the engine and causes a flow change, but this does not explain the fact that in level flight, anytime down elevator is applied, the engine loads and sputters. If the carb was functioning properly, there should be no rpm changes despite the position of the plane/tank.
The carb seems to be sensitive to positional changes. I would like to think that Saito is working on a better carb design for this engine and that it might be available in the near future. Patience may prevail in this situation. Sending the engines back for repair seems to be a waste of time. The engines will run well on a test stand giving the impression that nothing is wrong. It's only when the engine is installed and airborne does it become problematic. I know I won't be buying one anytime soon!
#284
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RE: Saito FG-20 or 21
I wonder Sailfish, did you try to lean the top end by one click. I have had and seen gas engines do the same thing in planes, and all that was needed was to lean the top end a little.
My evolution engine did the same thing. These engines are very particular on where the settings are. My evolution engine has a Walbero carb on it and it did the same thing. I don't know if you have owned a gasser before, if not, then have somebody at your field help. Gas engines are much different then glow when it comes to tuning.
I hope that it is something that easy. Don't give up and keep us in the loop!!!!
My evolution engine did the same thing. These engines are very particular on where the settings are. My evolution engine has a Walbero carb on it and it did the same thing. I don't know if you have owned a gasser before, if not, then have somebody at your field help. Gas engines are much different then glow when it comes to tuning.
I hope that it is something that easy. Don't give up and keep us in the loop!!!!
#285
Thread Starter
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RE: Saito FG-20 or 21
ORIGINAL: modelflyer5
I wonder Sailfish, did you try to lean the top end by one click. I have had and seen gas engines do the same thing in planes, and all that was needed was to lean the top end a little.
My evolution engine did the same thing. These engines are very particular on where the settings are. My evolution engine has a Walbero carb on it and it did the same thing. I don't know if you have owned a gasser before, if not, then have somebody at your field help. Gas engines are much different then glow when it comes to tuning.
I hope that it is something that easy. Don't give up and keep us in the loop!!!!
I wonder Sailfish, did you try to lean the top end by one click. I have had and seen gas engines do the same thing in planes, and all that was needed was to lean the top end a little.
My evolution engine did the same thing. These engines are very particular on where the settings are. My evolution engine has a Walbero carb on it and it did the same thing. I don't know if you have owned a gasser before, if not, then have somebody at your field help. Gas engines are much different then glow when it comes to tuning.
I hope that it is something that easy. Don't give up and keep us in the loop!!!!
#286
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RE: Saito FG-20 or 21
Original: ALpmc
Heat may be a problem as most 2 stroke gassers have a phenolic (or other material) standoff to keep heat from transferring to the carb.
Heat may be a problem as most 2 stroke gassers have a phenolic (or other material) standoff to keep heat from transferring to the carb.
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#287
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RE: Saito FG-20 or 21
Maybe some engine gurus can provide some explanations for some of the experiences I've had. I first tuned it like a typical Saito, leaned out the top end (9000 richened down to 8900), then leaned out the low speed to get a nice idle at 1900-2000rpm, so, great top end and idle, BUT, at the half throttle position (about 6-7000) it ran rich. After much fiddling with the needles I finally smoothed out the mid range by leaning out the LOW speed needle and then had to compensate by richening the high speed a bit (Maybe some cumulative effect of the two needles on gas carbs?). Then it ran smooth at all rpms. After shutting the engine down to let it cool I couldn't get it restarted, checked the hi needle, only out 3/4 turns! Set it at 1 1/4, motor then starts but is rich, then have lean it out again. Reminds me of my Cox 049 days, start rich then lean it every start! I was thinking since there is no choke and maybe no pump pressure at start up the needle has to be rich, but after the engine starts the fuel pressure builds and forces more fuel thru the jet and the needle then needs to be turned in?
Some of my thoughts about this engine are; Maybe the pump does not provide a very consistent pressure to the carb and maybe the needle valves aren't high enough resolution to set and keep a good mixture? Also, with the high oil content and occasional rich running maybe the plug has a tendency to foul?
Some of my thoughts about this engine are; Maybe the pump does not provide a very consistent pressure to the carb and maybe the needle valves aren't high enough resolution to set and keep a good mixture? Also, with the high oil content and occasional rich running maybe the plug has a tendency to foul?
#289
Thread Starter
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RE: Saito FG-20 or 21
ORIGINAL: eddyc
Maybe some engine gurus can provide some explanations for some of the experiences I've had. I first tuned it like a typical Saito, leaned out the top end (9000 richened down to 8900), then leaned out the low speed to get a nice idle at 1900-2000rpm, so, great top end and idle, BUT, at the half throttle position (about 6-7000) it ran rich. After much fiddling with the needles I finally smoothed out the mid range by leaning out the LOW speed needle and then had to compensate by richening the high speed a bit (Maybe some cumulative effect of the two needles on gas carbs?). Then it ran smooth at all rpms. After shutting the engine down to let it cool I couldn't get it restarted, checked the hi needle, only out 3/4 turns! Set it at 1 1/4, motor then starts but is rich, then have lean it out again. Reminds me of my Cox 049 days, start rich then lean it every start! I was thinking since there is no choke and maybe no pump pressure at start up the needle has to be rich, but after the engine starts the fuel pressure builds and forces more fuel thru the jet and the needle then needs to be turned in?
Some of my thoughts about this engine are; Maybe the pump does not provide a very consistent pressure to the carb and maybe the needle valves aren't high enough resolution to set and keep a good mixture? Also, with the high oil content and occasional rich running maybe the plug has a tendency to foul?
Maybe some engine gurus can provide some explanations for some of the experiences I've had. I first tuned it like a typical Saito, leaned out the top end (9000 richened down to 8900), then leaned out the low speed to get a nice idle at 1900-2000rpm, so, great top end and idle, BUT, at the half throttle position (about 6-7000) it ran rich. After much fiddling with the needles I finally smoothed out the mid range by leaning out the LOW speed needle and then had to compensate by richening the high speed a bit (Maybe some cumulative effect of the two needles on gas carbs?). Then it ran smooth at all rpms. After shutting the engine down to let it cool I couldn't get it restarted, checked the hi needle, only out 3/4 turns! Set it at 1 1/4, motor then starts but is rich, then have lean it out again. Reminds me of my Cox 049 days, start rich then lean it every start! I was thinking since there is no choke and maybe no pump pressure at start up the needle has to be rich, but after the engine starts the fuel pressure builds and forces more fuel thru the jet and the needle then needs to be turned in?
Some of my thoughts about this engine are; Maybe the pump does not provide a very consistent pressure to the carb and maybe the needle valves aren't high enough resolution to set and keep a good mixture? Also, with the high oil content and occasional rich running maybe the plug has a tendency to foul?
#290
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RE: Saito FG-20 or 21
Didn't Saito say they spent 2 years with this engine? They probably never took it off the test bench and put it in the air. If Horizon is following this thread they should let us know they are on this problem and will fix this engine when they have an answer. I received my Walbro WT 456 the other day and hope to try that out soon. It is bigger and heavier than I expected but it is the smallest carb for a 4 stroke.
#291
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RE: Saito FG-20 or 21
I was comparing the FG-20 needle valve with my 125 needle valve and if they were thrown in a box, you wouldn't know which is which. They will fit either engine. The threads, total length, and taper appear the same.
I also noticed that the FG-20 throttle barrel has a spring behind it whereas the 125 does not.
I measured the plug gap at .5mm and it was fouled with a piece of carbon.
It is a real chore to install/remove the cap on the plug. The plug's insulator was black dirty on a white napkin. Inside the cap, the wire doesn't appear to have a very positive connection the the plug center electrode when installed?
The FG-20 crank is 1/4" longer overall than the 125 to allow for the longer length of the prop driver/magnet
Two wires to the timing sensor
I also noticed that the FG-20 throttle barrel has a spring behind it whereas the 125 does not.
I measured the plug gap at .5mm and it was fouled with a piece of carbon.
It is a real chore to install/remove the cap on the plug. The plug's insulator was black dirty on a white napkin. Inside the cap, the wire doesn't appear to have a very positive connection the the plug center electrode when installed?
The FG-20 crank is 1/4" longer overall than the 125 to allow for the longer length of the prop driver/magnet
Two wires to the timing sensor
#292
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RE: Saito FG-20 or 21
You are correct we do have a 2 year warr on the engine but every time I send it back it cost me $18.00. I am just spending good money for nothing. I will be very surprised if they find any thing wrong with the engine this time. Last time note said check good no problem noted. I don't think Saito cares look at some of the post in the glow section. I have waisted $ 570.00 on this paper weight so far. I have spent my last dollar at Horizon.
#293
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RE: Saito FG-20 or 21
I was so excited when I heard about this engine that I went out and bought one as soon as they were available. Then immediately two things were suspect; first that Saitos manual was so far off on the initial needle settings, which they later changed, then they changed the after break-in gas/oil ratio from 30:1 to 20:1. This after two years of development?
I think this fg-20 carb might be a dud. I'm thinking of putting a 125 alcohol carb on this thing and try running glow fuel with the spark ignition. At a glance it looks as if the 125 and fg-20 are close enough that you could swap out carbs?
I think this fg-20 carb might be a dud. I'm thinking of putting a 125 alcohol carb on this thing and try running glow fuel with the spark ignition. At a glance it looks as if the 125 and fg-20 are close enough that you could swap out carbs?
#294
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RE: Saito FG-20 or 21
Bill Brundle, this is addressed to you. You are supposeddly the person working on these engines for Horizon/Saito. You told me you would talk to me after Toledo! I sent you a long email describing all of the things I did to my motor. What is going on? Everbody is getting tired of this situation with this motor/paper weight. I DO NOT BELIEVE that there is not a problem with the FG-20. How is it going to be resolved? You run the engines on a test stand upright, you told me I needed to make my setup like yours. Don't you think for the most part, it should not matter how the motor is situated? There are a lot of planes and there are going to be many different setups by different people. The motor should just run without all of this monkeying around. PLEASE RESPOND, ALL OF US WANT TO KNOW WHAT HORIZON/SAITO IS GOING TO DO FOR US. It is more than just a couple of people.
R/C Foolish
R/C Foolish
#295
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RE: Saito FG-20 or 21
ORIGINAL: bbrundle
Guys
Yes we do monitor the RCU forums and we/I do try to provide support and answers to the best of our abilities.
I was personally involved in the diagnosis of this engine and as Scott has stated we tracked the issue down to the carburetor. Basically the engine would idle great, transition was great, High speed on a 16-6 APC was great. The issue was at around 7000 RPM in that we noticed a sort of miss and we could manipulate the RPM where this miss occurred with the LS needle settings. The LS needle does interact with the HS needle through the majority of the transition from idle to high speed so if you find yourself looking to adjust the LS needle from the recommended 4 1/2 turns in from flush to the Carb. arm then please make very small 10 minute changes to the screw. Please note that the carb settings listed in the manual are for hte FG-36 and we have an addendum posted on our web- site on theFG-20 page with the correct settings.
Basic settings as follows:
HS 1 1/8-1 3/8
LS 4 1/2 turns in on the screw from a starting point of flush to the face of the throttle arm
We replaced the carburetor and then proceeded to run the engine for another 20 minutes or so through varied throttle settings and found the engine to be running perfectly.
Regarding the oil content we recommend please keep in mind as stated earlier that there are no needle bearings in the FG-20 engine and the additional lubrication is a must. You will not find any additional gains in HP or RPM by using a 50:1 or 100:1 mix in this engine. You must as we recommend use a high quality 100% Synthetic oil mixed at 20:1
I would strongly recommend the use of our Evolution oil at this mix rate as it is made by Morgan fuels and is fantastic. The boys at Saito for reference are using Klotz Synthetic also at the 20:1 Something to keep in mind is that the FG-20 engine is only consuming approx. 10-12 cc of gas per minute on average and at 20:1 you are only feeding the con rod and bearings .6cc per minute of oil. Not much when you consider that the Saito 125 burns methanol fuel with 18%-20% oil at a rate of 40cc per minute which equates to .7-.8 cc of oil per minute. Keep in mind the additional heat from gas versus methanol (glow Fuel)and you will see the reasoning behind the additional oil.
Now if you talk to the boys at DA and Bobby at Cactus Avitaion (3W), Gerhard at Aircraft international(3W) and oh of course Horizon (Evolution) we are all aware of the varying effect of different oils and the carbon deposits that are left behind from some oils. Carbon is almost always present in a gasoline engine and must be kept in check with the proper use of high quality oils.
These new gasoline 4-stroke engines have been thoroughly tested and I think are a great testimonial of the dedication to quality that Saito has been delivering for many many years
If you have a question for either myself or one of our engine techs we will do our best to make ourselves available. Send me a PM and I will get back to you as soon as possible. You can call our Product support as mentioned previously and ask to talk to one of our engine techs and they will call you back when they have their first opportunity.
If you will be attending the Weak Signals Toledo Trade Show then please stop by and say hello.
Sorry to be so long winded...
Happy flying
Guys
Yes we do monitor the RCU forums and we/I do try to provide support and answers to the best of our abilities.
I was personally involved in the diagnosis of this engine and as Scott has stated we tracked the issue down to the carburetor. Basically the engine would idle great, transition was great, High speed on a 16-6 APC was great. The issue was at around 7000 RPM in that we noticed a sort of miss and we could manipulate the RPM where this miss occurred with the LS needle settings. The LS needle does interact with the HS needle through the majority of the transition from idle to high speed so if you find yourself looking to adjust the LS needle from the recommended 4 1/2 turns in from flush to the Carb. arm then please make very small 10 minute changes to the screw. Please note that the carb settings listed in the manual are for hte FG-36 and we have an addendum posted on our web- site on theFG-20 page with the correct settings.
Basic settings as follows:
HS 1 1/8-1 3/8
LS 4 1/2 turns in on the screw from a starting point of flush to the face of the throttle arm
We replaced the carburetor and then proceeded to run the engine for another 20 minutes or so through varied throttle settings and found the engine to be running perfectly.
Regarding the oil content we recommend please keep in mind as stated earlier that there are no needle bearings in the FG-20 engine and the additional lubrication is a must. You will not find any additional gains in HP or RPM by using a 50:1 or 100:1 mix in this engine. You must as we recommend use a high quality 100% Synthetic oil mixed at 20:1
I would strongly recommend the use of our Evolution oil at this mix rate as it is made by Morgan fuels and is fantastic. The boys at Saito for reference are using Klotz Synthetic also at the 20:1 Something to keep in mind is that the FG-20 engine is only consuming approx. 10-12 cc of gas per minute on average and at 20:1 you are only feeding the con rod and bearings .6cc per minute of oil. Not much when you consider that the Saito 125 burns methanol fuel with 18%-20% oil at a rate of 40cc per minute which equates to .7-.8 cc of oil per minute. Keep in mind the additional heat from gas versus methanol (glow Fuel)and you will see the reasoning behind the additional oil.
Now if you talk to the boys at DA and Bobby at Cactus Avitaion (3W), Gerhard at Aircraft international(3W) and oh of course Horizon (Evolution) we are all aware of the varying effect of different oils and the carbon deposits that are left behind from some oils. Carbon is almost always present in a gasoline engine and must be kept in check with the proper use of high quality oils.
These new gasoline 4-stroke engines have been thoroughly tested and I think are a great testimonial of the dedication to quality that Saito has been delivering for many many years
If you have a question for either myself or one of our engine techs we will do our best to make ourselves available. Send me a PM and I will get back to you as soon as possible. You can call our Product support as mentioned previously and ask to talk to one of our engine techs and they will call you back when they have their first opportunity.
If you will be attending the Weak Signals Toledo Trade Show then please stop by and say hello.
Sorry to be so long winded...
Happy flying
I went to the Horizon area on Friday and there was just some young girl there. He wasn't around
#298
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RE: Saito FG-20 or 21
Hi guy's, This is my first post, however I have been following this thread for the last few weeks. I also own a fg-20 paper weight. I have sent it back once to Horizon. Still not fixed. I just wanted to add my name to the list of unhappy Saito fg-20 owners. Probably a lot more of us out there.
#299
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RE: Saito FG-20 or 21
Welcome Oldtechy - Sorry to hear you have an FG 20 that doesn't work properly either. I think it is safe to guess that those of us in this forum with FG 20 problems are just the tip of the iceberg. I am going to try a 6v battery today just for the heck of it. Horizon said you could use a 6v without a regulator with the Saito ignition. I also have the WT 456 Walbro carb that is next for this thing. Just have to have the adapter made for the intake manifold.
#300
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RE: Saito FG-20 or 21
I was at the field today to test a 6v battery and see if it made any difference at the high end with a hotter spark. Well, as you might guess, there was no difference. TKG said this would be a good test whether the problem pointed to the ignition or the carb. So at this point, I believe all points to the carb being the problem on the FG 20. I am working on hooking up the WT 456 carb to it and that should give the final word on this. I think this delay will be at least two weeks until I can get a part made up and test. To all other FG 20 owners, I would not beat my head against the wall trying to tweak it and sending it to Horizon is a waste of time right now. You might want to wait and see what a Walbro carb will do.