Notices
Gas Engines Questions or comments about gas engines can be posted here

Saito FG-20 or 21

Old 08-25-2015, 10:52 AM
  #1776  
w1nd6urfa
Senior Member
My Feedback: (4)
 
w1nd6urfa's Avatar
 
Join Date: Aug 2008
Location: EllinikoAthens, GREECE
Posts: 1,079
Likes: 0
Received 5 Likes on 5 Posts
Default

Looks good, let us know how it goes
Old 01-21-2017, 02:23 PM
  #1777  
mustangherb
My Feedback: (6)
 
Join Date: Feb 2013
Location: Portsmouth, VA
Posts: 118
Received 0 Likes on 0 Posts
Default

I just picked up a cub recently with the Saito FG-20. I seem to have a similar problem on my engine. The engine will idle fine and run fine a above 7000, but nothing in between. I tried the base setting on low speed and the results are the same. Not sure how long the engine has been sitting. High speed on a 16 x 6 MS is 8500. Sound of the engine at idle and at high speed sounds smooth.
Old 01-21-2017, 03:45 PM
  #1778  
Saillfish
Thread Starter
My Feedback: (17)
 
Join Date: Sep 2003
Location: Lubbock, TX
Posts: 280
Received 2 Likes on 2 Posts
Default

Mustangherb, best thing you can do is pull that motor and sell it to some poor guy. Or throw it away if you don't want to screw some poor guy. I am being serious!
Old 01-21-2017, 03:54 PM
  #1779  
R/C Foolish
My Feedback: (6)
 
Join Date: Jan 2003
Location: BILLERICA, MA
Posts: 1,331
Likes: 0
Received 0 Likes on 0 Posts
Default

This might sound silly, try running 4 stroke glow fuel thru it with the ignition. Before I sold mine, that was the only way I could run it. The problem with that Saito motor is it's a glow needle valve trying to run gas, doesn't work. Works fine with glow fuel and you never have a dead stick. Problem is you are still using expensive glow fuel so no savings....
Old 01-21-2017, 04:27 PM
  #1780  
mustangherb
My Feedback: (6)
 
Join Date: Feb 2013
Location: Portsmouth, VA
Posts: 118
Received 0 Likes on 0 Posts
Default

Not ready just yet to throw in the towel. I guess I am gluten for punishment or just plain stubborn.
Old 01-21-2017, 04:31 PM
  #1781  
R/C Foolish
My Feedback: (6)
 
Join Date: Jan 2003
Location: BILLERICA, MA
Posts: 1,331
Likes: 0
Received 0 Likes on 0 Posts
Default

I don't know of anybody still using that motor...
Old 01-21-2017, 06:11 PM
  #1782  
ForcesR
 
Join Date: Dec 2009
Location: Ottawa, ON, CANADA
Posts: 885
Likes: 0
Received 10 Likes on 9 Posts
Default

Mustangherb; I have been running my FG20 in my TF Spitfire since 2010 and it runs very well and sounds awesome. I love my Saito's, FG20, FG36, FG60R3 and my FA100. I have never had a problem with the FG20 since HH sent me a replacement carburetor in 2010. Your FG20 may have the old carburetor, the one that was a problem until they replaced it free of charge to customers back then. Check the part number on the carburetor, if it's not part number SAIG20821A than it's the problem carburetor you have on your FG20. Just for your info, HH has carburetor SAIG20821A in stock.

Roger
Old 01-21-2017, 06:38 PM
  #1783  
jaav
Senior Member
 
Join Date: Aug 2008
Location: Broome, AUSTRALIA
Posts: 1,552
Likes: 0
Received 0 Likes on 0 Posts
Default

I gave up on mine.... replaced it with a FG19R..
Old 01-21-2017, 09:45 PM
  #1784  
w1nd6urfa
Senior Member
My Feedback: (4)
 
w1nd6urfa's Avatar
 
Join Date: Aug 2008
Location: EllinikoAthens, GREECE
Posts: 1,079
Likes: 0
Received 5 Likes on 5 Posts
Default

Mustabgherb,
Ditto on what ForcesR said - make sure you have the new carb with the pin hole
Also get a CH Ignition kit for the FG-20, that did it for me - like a different engine!

Pic of the carb pin hole:

Old 01-21-2017, 09:48 PM
  #1785  
w1nd6urfa
Senior Member
My Feedback: (4)
 
w1nd6urfa's Avatar
 
Join Date: Aug 2008
Location: EllinikoAthens, GREECE
Posts: 1,079
Likes: 0
Received 5 Likes on 5 Posts
Default

And a quick flyby of the FG20 on a Spitfire

https://www.youtube.com/watch?v=ZRON2DVcmfY
Old 01-22-2017, 04:15 AM
  #1786  
mustangherb
My Feedback: (6)
 
Join Date: Feb 2013
Location: Portsmouth, VA
Posts: 118
Received 0 Likes on 0 Posts
Default

Originally Posted by w1nd6urfa
Mustabgherb,
Ditto on what ForcesR said - make sure you have the new carb with the pin hole
Also get a CH Ignition kit for the FG-20, that did it for me - like a different engine!

Pic of the carb pin hole:

Thank ForcesR and w1nd6urf for the valuable info on the carburetor. Also to everyone else for their input. I have to say that the RC community is overall has some of the most helpful and nice people.
Old 01-22-2017, 04:33 AM
  #1787  
mustangherb
My Feedback: (6)
 
Join Date: Feb 2013
Location: Portsmouth, VA
Posts: 118
Received 0 Likes on 0 Posts
Default My FG-20 carburetor

Okay I do have the original carburetor on my FG-20 engine
Old 02-08-2017, 05:40 PM
  #1788  
mustangherb
My Feedback: (6)
 
Join Date: Feb 2013
Location: Portsmouth, VA
Posts: 118
Received 0 Likes on 0 Posts
Default

My experience so far with a plane I picked up recently that had a extreme low time Saito FG-20 was right inline with most of the problems talked about on the forums. My engine even still has the original carb. Call me stubborn, but I went to work to see if I could get the engine to run correctly. I pulled the engine from the plane to install it on the stand and the first thing that I discovered on the very first run on the stand was studder in the engine if I moved the ignition module. After some investigation I discovered an error from the factory in the crimping of the wires onto the pins in the plug of the pickup. After correcting that problem the engine studder cleared up, but the midrange still needed work. It took me two things to fix this problem. One I installed fuel barbs & zip ties on all the tank lines inside and out. Secondly I played a round with the tank placement and now the engine is running great in all the flight conditions in the plane. I must admit that I was worried after reading some of the horror stories, but you just have to ensure that the fuel system is tight(I installed fuel barbs), the module plugs are crimped correctly and that you get the fuel tank placement right. I must admit that after reading through this threads that I seriously had my doubts about the engine, but I flew the plane several times today and the engine is running fantastic.
Old 07-02-2017, 09:15 PM
  #1789  
OliverJacob
My Feedback: (12)
 
Join Date: Jul 2011
Location: Reedsburg, WI
Posts: 700
Likes: 0
Received 0 Likes on 0 Posts
Default

So I picked up a low time FG20 and after reading this, I guess I know why it hasn't been running a lot...
Anyways - it had been crashed and needs a few parts. Besides push rods and sleeves and a broken needle valve I'll need a muffler and fitting - would an ASP part fit here?

The carb seems to be the old version, so I need to decide if I get just the broken parts or an upgraded carb.

What's a good source for spare parts?

thanks
Old 07-03-2017, 06:23 AM
  #1790  
acdii
 
Join Date: Jan 2011
Location: Capron, IL
Posts: 9,996
Received 97 Likes on 88 Posts
Default

Hmm, I seem to recall someone selling that engine on FB. Didn't realize the exhaust was mucked up too. You can get parts from Horizon. Look into maybe a turbo header instead of stock muffler, gives it more power.
Old 07-03-2017, 07:05 AM
  #1791  
mustangherb
My Feedback: (6)
 
Join Date: Feb 2013
Location: Portsmouth, VA
Posts: 118
Received 0 Likes on 0 Posts
Default Muffler

I have used both the stock muffler on my FG-20 and an RC Specialties muffler with right angle adapter with great success. If I had my choice I would definitely use the RC Specialties muffler versus the stock muffler.
Old 07-03-2017, 09:53 AM
  #1792  
OliverJacob
My Feedback: (12)
 
Join Date: Jul 2011
Location: Reedsburg, WI
Posts: 700
Likes: 0
Received 0 Likes on 0 Posts
Default

Thanks, I just put on an order with Horizon, except the muffler.
I may have one laying around here, i just want to make sure I get this engine to run before buying more parts.
Not such a great deal after all, but there is no turning back, I'll get it going sooner or later
Old 07-03-2017, 11:06 AM
  #1793  
mustangherb
My Feedback: (6)
 
Join Date: Feb 2013
Location: Portsmouth, VA
Posts: 118
Received 0 Likes on 0 Posts
Default

The Saito FG-20 muffler has 13mm threads and the only other Saito with those threads are the Saito 125.
Old 07-03-2017, 11:08 AM
  #1794  
OliverJacob
My Feedback: (12)
 
Join Date: Jul 2011
Location: Reedsburg, WI
Posts: 700
Likes: 0
Received 0 Likes on 0 Posts
Default

That's really an odd size, thanks
Old 07-04-2017, 05:36 AM
  #1795  
AA5BY
 
Join Date: Sep 2006
Location: White Oak, TX
Posts: 2,398
Likes: 0
Received 2 Likes on 2 Posts
Default

The difficulties with the FG-20 narrated here caught my interest as I've recently converted a 1.25A to gas with minimal problems using the stock carb. Muffler pressure is used and tuning is tight but not much more so than my Evolution gas engines.

Idle was a bit of a problem but was solved by using a throttle servo speed delay of one second. The delay allowed leaning the idle up enough to get the carb barrel closed to a more normal idle position. Without the delay, idle had to be fat with a somewhat open barrel and of course that restricted it to a fast idle.

Leaning the idle to obtain a smoother and lower idle introduced a spool up stumble that would kill the engine but that was overcome with servo speed slow down. The slow down really doesn't effect flight as spool up happens in about the same time frame, it just prevents a drastic upset of the fuel/air/rpm ratio by opening the barrel and drawing out the metering needle at a speed that gives the rpms enough time to keep up to the changes.

If stumbling is a problem with the FG-20, try a servo speed slowdown.
Old 07-04-2017, 06:44 AM
  #1796  
acdii
 
Join Date: Jan 2011
Location: Capron, IL
Posts: 9,996
Received 97 Likes on 88 Posts
Default

That is actually a pretty good idea. I'll have to remember that trick. It should also work on glow engines. I have an OS that is finicky at times. I think I may need to replace the o rings on the LSN on that one as the low end keeps changing.
Old 07-04-2017, 11:05 AM
  #1797  
OliverJacob
My Feedback: (12)
 
Join Date: Jul 2011
Location: Reedsburg, WI
Posts: 700
Likes: 0
Received 0 Likes on 0 Posts
Default

I did have the same problem on other engines, and found them hard to tune for sudden throttle changes.
A delay would probably help out a lot. I'll try that.

Thank you
Old 11-04-2017, 04:48 AM
  #1798  
SWORDSN
My Feedback: (13)
 
Join Date: Jun 2004
Location: WILLIAMSTON, SC
Posts: 1,126
Likes: 0
Received 2 Likes on 2 Posts
Default

A fellow club member has two of the 21cc engines and the cylinder heads have cracked on both. Anyone else had this problem?
Old 11-04-2017, 05:04 AM
  #1799  
Timbers
My Feedback: (3)
 
Join Date: Feb 2008
Location: Waukesha, WI
Posts: 223
Likes: 0
Received 1 Like on 1 Post
Default No

Wow they both cracked? Can you post a pic that shows how they were mounted? If they are in a cowl and don’t have heavy airflow thats aimed directly over the head with some custom made baffling then they will get screamin hot. I’m guessing the aluminum softened up and cracked due to excessive heat.
Old 11-04-2017, 06:55 AM
  #1800  
acdii
 
Join Date: Jan 2011
Location: Capron, IL
Posts: 9,996
Received 97 Likes on 88 Posts
Default

Or ran the wrong mixture. You MUST run 20:1 in these, or even 16:1 or they will run too hot.

Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.