ScottMcM

My Feedback: (66)

That sounds like a great idea. I wonder if anyone else has tried this?

Timbers

My Feedback: (3)

Almost a gallon through my FG-21, running nice so far. If that exhaust valve seat stays put I'd say we have a winner.

For the FG-20 guys I'd ask Horizon if they are working on a jug for the FG-20s that has pressed in valve seats. My FG-20 ran great, its just the exhaust valve seat would blow out after a gallon or two. If Horizon and Saito would come out with a new jug to fix that problem I think they would make a lot of FG-20 guys happy.

Biggles2

Im not sure what you mean when you say muffler pressure? are you saying that your pressurising the fuel tank from the muffler rather than using saito's own pump system . Im intrigued to learn more how this helps smoother more efficiant running , because I could with some advice here otherwise its heading for the scrap heap.

Duayne P

My Feedback: (15)

Hi All, been following this thread for awhile. I have an FG20 with a ch ignition and it has pressure from exhaust. Almost a gallon through with out a problem. Had issues a wile back with the engine starting to lean out after 5 min of flight, put pressure and never again. Love this motor. The only thing done was ch ignition and updated carb. Ran the engine for a solid hour, tune and fly. Have it in .90 Ultimate. The engine pulls great, only maneuver I cant do is hover, just not enough power. Also running a 15x8 APC at 8500rpm. Thanks for all the info guys!!

AeroFinn

Hi

Aren't you worried about flaming hot gasses as you use muffler pressure? Just a thought

Duayne P

My Feedback: (15)

I did think about that. Then saw an Evolution 10cc and 15cc with muffler pressure from the manufacturer and that did it. Also, there is no spark to ignite the fumes in the tank or anyway for a spark to get in the tank. Also when the motor isn't running, it will vent any fumes in the tank. Just don't smoke around the plane for a wile after flight. So far so good, no problems at all and the engine runs awesome. I'm not trying to tell everyone to do what I did, just commenting on my great running motor because I see a lot of negative comments about this engine. Just wanted to share my positive success with this motor.[8D]

rhd-RCU

My Feedback: (36)

What did you mean by updated the carb. I am still running the original carb.

Timbers

My Feedback: (3)

RD!

Horizon had an updated carb that they were sending people. I think when I swapped I just had to send my carb back and they sent me the new one. I forgot what the difference was, I think the needle was modified as well as that small hole in the back of the case. Call Horizon I'm sure they will still send you the new one if you ask.

...Tim

ScottMcM

My Feedback: (66)

How might the updated carb be identified? I bought my FG-20 used, and don't know if it has the updated carb. Thanks.

Timbers

My Feedback: (3)

The new carb will have a small dot stamped on the back of it. There was plenty of talk about this subject in this thread, but you might have to go back quite a ways. I believe some people posted pictures of what the dot looked like. Its just a stamped dimple in the back. See if you can find the pics that should help.

rhd-RCU

My Feedback: (36)

Thanks Tim.

ScottMcM

My Feedback: (66)

Yes, thanks

AeroFinn

This is interesting, I wasn't aware of Evolution gas engines using muffler pressure. I even checked the manual and this definitely is true. However, 4-stroke engines run hotter than two strokes so this might be another thing to consider about. But since you are doing ok It's probaly a safe solution. I wonder why there aren't many others doing the same, though. But each and everyone his own preferences, of course.

I'm converting my FA-125a engine to CH ignitions CDI and will run the engine on glow fuel, at least for a while. However, if the muffler pressure is a safe solution why not testing the original carb & gas fuel as I'v been told the original carb is ok but you need a pump / muffler pressure to help the engine run properly when flying the model

triumphman49

My Feedback: (149)

The amount of gases that can enter the gas tank equal the amount of fuel drawn. In other words, the gases travel the tubing from muffler very slow and any spark would certainly be no more by the time it made it into the tank

T-man49 in Al
Club Saito 723
Spitfire Bro 19

Arruda

Regarding this subject of pressurizing gas fuel tanks, I think it should be a good idea to put one of these fuels filters with a metallic mesh element in the line between the muffler and the tank.
Flames don’t pass through metallic meshes.
Just in case…

rhd-RCU

My Feedback: (36)

A good idea.

hugj

My Feedback: (7)

Hey guys I have a fg21 since dec the motor runs fine top end but when you come back to idle it holds 2 to 3000 rpm if you let it sit and idle there then it drops to 1800 to 2000 with no idle trim input. the one thing that is strange if you get near the low needle with a screw driver to adj it the idle changes.

horizon is sending a new carb body? not the whole thing because its out of stock! I have been fighiting this problem since new Any other thaughts

thanks

w8ye

My Feedback: (16)

The idle setting is too lean.

You have to adjust the low needle with the engine not running because the barrel is spring loaded to push it out.

The bigger ones with the Walbro carb are spring loaded to push the barrel in.

Duayne P

My Feedback: (15)

My FG-20 was the same way. You are too lean. Start richening 1/8 turn at a time. It solved my problem. Engine runs like a top. I adjust my engine when its running. Yes the idle changes due to the carb being spring loaded w8ye is rite on about the different carbs.. All I do is after the the adjustment I pop the to half and back down to idle. Let the engine run at full throttle for a couple of seconds then to idle. If the idle is still high and the lowers richen 1/8 again and repeat. Hope this helps.

WindGap

My Feedback: (3)

My stock spark plug was a piece of junk. Should I upgrade to the rimfire vr2 or another? Please advise. Also, do I need to make any mods to fit it? Thanks.

alan0899

G'day Windgap
I have had no problems at all with the original Saito spark plug, I even bought a spare, just in case.
Is it possible that you are running motorcycle oil in the fuel in your engine. The wrong oil will burn & cause carbon deposits on your plug.
The oil should not burn, if it does, it is not lubricating, I use Coolpower Blue oil, the same as I use in my glow engines, it, like Klotz R50 & Redline oil,
does not burn causing the valves to gum up, & excessive carbon build up.

Cheers

WindGap

My Feedback: (3)

The center metal rod pulled out. So I need a new spark plug.

Heli-NuBee

I picked up a NIB Sig P-51B airplane the other day and then ordered a Saito FG-21 to power it. At first glance, the FG-21 looked like the perfect match for the P-51B but after reading much of this forum, I am concerned that I may have made a poor choice. I don't see a lot of positive feed back on the Saito FG-20 & FG-21 engines. I sure hope that the newer version FG-21 works out with my P-51-B.

Best wishes and good safe flying.

Heli-NuBee (AKA Roger the radial rabbit)

w1nd6urfa

My Feedback: (4)

A warning to all FG-21 owners:

The Saito Gas Engines manual lists the wrong part number for the cylinder, on page 31 it states SAI G2001 which is the FG-20 part no, the correct one is SAI G2101

Ask me how I know: I ordered the one listed in the manual, now waiting for Advantage Hobby to approve the replacement ...

After so much disappointment over the FG-20 one would think HH would be more careful with the FG-21 not allowing such mistakes cause more trouble to customers?

Kentli22

I just got the FG21 recently, I think the quality of this engine is fine. I'd mounted it on the airplane to do the gound run in, I did the ground run in according to the manual, everything went just fine. Now I'd had 3 flights so far, there wasn't a single problem. 16x6 Master Screw, WOT current at 9,600rpm, idle and transition are all proper. The sound of this 4-stroke is louder and to my taste is not as nice as the FG33R3, and vibrates more too. One little problem I had after the 2nd flight, the valve spring become sticky and didn't spring back immediately, and caused the valve rod to go out of place and hence lost compression. I don't know why this happened. I just used a tiny flat head crew driver to reach between the springs to wipe it off with a napkin, not sure if that helps anything, but after that it springs back normally, and the engine runs correctly again. I made the 3rd flight after that, and nothing went wrong.