RV4flyer

Oops, won't use that bold type thing again, because I can hear it now, "DON"T YELL!"..
Sorry, first post, ok, learning curve.

grgfraz

thanks RV i looked at mine today and it has no mark ,my engine has never run right in the air so the carb is going back to horizan shortly,

RV4flyer

I'm sure everyone figured out I meant OCT. 2009, not Oct. 2010.

Oh well, and so it goes.

marcopolo

My Feedback: (1)

Pete,

I haven't put a tach to it other than to ensure I didn't exceed 4000rpm on the initial run. Next time I run it up I will let you know the revs at WOT. Now that you mention the higher octane rating I think I am running 89 octane which is a mid grade here in Minnesota. I have a KMP PC-21 that I am considering putting an FG-36 in. That sounds like a good combo.

Mark

Timbers

My Feedback: (3)

Just popped my carb off, sending it back to Horizon. I'm excited for Spring to try the engine out after the new carb, new ignition, 91 octane instead of 89!

...Tim

w8ye

My Feedback: (16)

The original sensor hole for the pump is very small in the original carb body. It is the size of a #56 drill. If you remove the pump assembly from the throttle body, It is in the lower left corner (Smallest hole in the chamber) and extends into the area behind the barrel where the barrel spring is. This hole extends through the pump body to the rear diaphragm area. The modification appears to be drilling this hole out to a #55 drill size?

There is a larger hole in the end of the barrel from the spring area into the venturi area of the barrel to complete the vacuum impulse sensor circuit path. There should be a picture below showing the hole in the blind end of the barrel that extends into the venturi area of the barrel. The bigger hole in the barrel end is for the spray bar.

Pete Bergstrom

AS mentioned in another post Saito has put a small punch mark on the inlet pipe side of the carb below the Needle Valve. All the engines we shipped to dealers after about 9-15 have the updated carb assembly. We held off on telling everyone about them until we had a sufficient stock of carbs on hand to satisfy everyone who has bought one of the engines.

Enjoy!

Pete Bergstrom
Saito Engine Manager
Horizon Hobby inc.

bells33

My Feedback: (19)

Ok... new here... yea, I went and bought a Saito FG20... Too cold here to do anything but I have ran it a few times to start the break in. I followed the book to the letter. Using EVO oil.. 20:1 etc. It seems that in the few engine runs that I had I was starting to get the tuning close. Obviously with this weather it will have to be totally redone once it gets warmer.

bells33

My Feedback: (19)

Ok... new here... yea, I went and bought a Saito FG20... Too cold here to do anything but I have ran it a few times to start the break in. I followed the book to the letter. Using EVO oil.. 20:1 etc. It seems that in the few engine runs that I had I was starting to get the tuning close. Obviously with this weather it will have to be totally redone once it gets warmer.

During one of the runs, I really thought the motor seized on me. The propeller just stopped dead and when I tried to turn by hand, it was pretty jammed up. When it cooled, I was able to free up and start it again.... it seemed ok. Is that possible? Should i return this thing and get it checked?

My last attempt to start was unsuccessful but I didnt spend a lot of time on it. I've noticed that unti it starts running, getting fuel to the carb is difficult. Is there a trick with these diaphragm carbs? Should I see fuel flowing even when not running (while pumping) or does it soley rely on the engine pressure to draw fuel in... if thats the case, how do you prime these things? I'm a little confused.

I'm going to try to start again today. I'm too itchy to wait until Spring.. haha. The plug seems a little dirty but I figured thats kind of expected during initial runnings of the motor. Good assumption? I was thinking about adding a drop of after run prior to start just to lube it up.... and of course I'll clean up that plug. Any suggestions on gap for plug??

Thanks for any help guys...

w8ye

My Feedback: (16)

The pump diaphragm in the carb only moves when there is a suction impulse in the intake manifold. When the intake valve closes, there is a spring that returns the diaphragm.

w8ye

My Feedback: (16)

I've noticed the engine to be problematic about the prime on a hot restart.

You could have the needles leaned to the point where it will not prime enough to restart

bells33

My Feedback: (19)

What about gap on plug? What should that be?

w8ye

My Feedback: (16)

The specified gap is .016" - .020"

Be careful about removing the plug to check for spark. The base of the plug must be grounded to the engine at all times there is power to the ignition.

Ohterwise, the spark will jump internally of the ignition unit and ruin it.

w8ye

My Feedback: (16)

Do you have the tank centered on the the center of the needle valve?

captinjohn

There are 2 big reasons not to try to break some engines in in cold weather. I am talking below 50 degrees. #1Parts of the engine will not heat up in a uniform matter. #2 If you have even read of the engine your are breaking in has some issues. Just park it until warm weather arrives. Also there may be new factory fixes your engine may qualify fore. You do not want to tinker with the engine & mess up your warranty. My brand new engines with no time at all on them wait to it gets warm. Capt,n

w8ye

My Feedback: (16)

Try closing the throttle on the carb and spin the engine to try to get the carb to prime

bells33

My Feedback: (19)

Makes sense... I don't feel comfortable starting it in this cold. I will say though, Istored the engine indoors overnight as not to try to start an ice cold engine. I am still very concerned about the one timethat it just stopped dead. This wasnt a stall. The prop went from an idle to just freezing mid rotation. I couldnt turn the the prop by hand until the engine cooled. It did run after that though.

I'm considering sending it back to get checked out. Ispoke to Horizon who said they would have no problem looking at it for me....

captinjohn

Engines like the Saito that have a high parts count deserve to be run "when new" in the right temps, so the engine will break in in a correct manor. I love engines...I treat them nice. Capt,n

hyltaiwan

http://www.youtube.com/watch?v=q72A7...ayer_embedded#

This FG20 seems running pretty good after 5 hours' break in.

http://www.youtube.com/watch?v=g2s4-...layer_embedded

bells33

My Feedback: (19)

I did notice the carb is very close to the fire wall so I drilled out some holes so that port on the back of carb can breath.... that should help fuel flow when starting... I think!

bells33

My Feedback: (19)

I have to say it was really bugging me that I couldn't fire up the motor yesterday. It was cold, but again, motor was kept indoors overnight. Anyway... last night I worked on some stuff. I drilled out the firewall behind the carb so that hole has breathing room. I also took out both high and low needles to inspect. Cleaned out plug.

Today was considerably warmer. Gave it a shot. Ihave to say, still not understanding how this carb is going to get gas into it without the engine actually running. When just trying to crank the motor, I dont see ANY fuel flowing to the carb. So I went ahead and manually dumped some fuel into it. Did that 3-4 times and she finally started running. After it warmed up, starting was not an issue.... one spin and it was running. Is that because there is already fuel in the lines??

I tell you what.... i think I got her purring nicely. I'm kind of psyched because I don't have much experience at all, but with all the reading I have done I feel i have a real good understanding. I was able to get her up to full RPM then richenedjust a little bit (per the book). Then got the transition from low to high revs real smooth and consistent.

I thinking the warmer weather will bring easier starts etc. Any feedback or advice on that would be great. The new SAITO pumped carbs seem to be something new from what I've read so I'm wondering if other FG-20 owners experienced same thing from a cold start.

Thanks for all the input guys!!!

w8ye

My Feedback: (16)

The pump in the Saito FG-14 & FG-20 is a diaphragm type pump. Suction in the intake manifold moves the diaphragm towards the engine and when the intake valve closes and the suction stops, there is a spring that returns the diaphragm to the original position.

The hole in the carb for the pump suction signal is in the spring end of the carburettor barrel. If the carb is very open most of the vacuum signal is lost at cranking speed. Therefore, it makes the pump hard to pick up a prime when you are trying to start the engine.

Also the pump is not a very powerful one and the tank must be mounted right up behind the engine and on the same level with the needle valve just like on a glow engine.

Although this is a pump carburetor, it does not exactly work like a Walbro or Zama carburetor on a chain saw or weed whacker. There is no demand regulator in the carb. Just two check valves for the pump and the pump diaphragm. By Theory, being as this carb has no demand regulator, a high tank position could cause gasoline to siphon right on through the carb and spill on the ground or hydro lock the cylinder depending on how the engine is mounted.

bells33

My Feedback: (19)

I think I'm on to something as far as my priming issue. I'm re-doing the fuel system today. Going to make some small changes. Any recommendations on what size fuel line to use?

hyltaiwan

If your FG20 is still on the test stand, I suggest you change to side mounted.(main needle point to the sky)
It is the best position for air to escape from the pump(if you ever disassembly the pump, you will know what I mean)
To prime the fuel line, switch off CDI,open throtle 1/5, use your finger to block the velocity stack, turn your propeller till
fuel just reach the carbulator and give 1-2 more turns, and no more.Power on CDI and start it.
3/32 ID fuel line is perfect for FG20.

bells33

My Feedback: (19)

Thanks for the advice.... yes... I am side mounting it. Already done. As I mentioned, I reworked the fuel system today. I realized Iwas using way too big diameter of fuel lines. Ithink that is going to make a big difference.

Stupid question, when you say "velocity stack" are you referring to the barrel on the carb? (sorry, still a newbee...haha)