Saito FG-14B - RC Groups
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Aug 23, 2011, 08:05 AM
Registered User

Saito FG-14B

I'm running in my Saito FG-14B 4-stroke gasser engine now on a test stand with a 14x6 prop (trying Coleman camping fuel and using Penrite Sin fully synthetic oil at 20:1).

I've set the high needle to 1 turn 20mins out from full closed as per the manual. But man o man it seems slobberingly rich.

The gunk that comes out of the exhaust is a black sticky mess and I need a catch tank under the blow by nipple to catch a very similar gunk. Raw fuel also collects at the carb inlet mouth.

My engine, out of the box, had the high needle at around 50 mins from full closed. Much leaner than the 1 turn 20mins in the manual. I can't believe Mr Saito was so far out, or could it be the manual is wrong or outdated? If the 1 turn 20mins is correct then I suspect running the engine with the needle at 50 mins may have damaged it very soon after first starting.

I haven't checked the low speed needle position but I'll now check that too.

Very keen to know of others run-in experience.

Where did your high speed needle end up?

And the low?

Last edited by brw0513_2; Aug 23, 2011 at 08:05 AM. Reason: Can't spell.
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Aug 23, 2011, 09:36 AM
Deal Honestly or Don't Deal
Throw out that Coleman fuel and use 93 octane gasoline with 6 1/4 oz of the Evolution oil per gal and you won't have those problems.

Aug 23, 2011, 09:46 AM
Methanol, The Cool Fuel !
Gary Cee's Avatar
Lower the tank and try again.

(Disregard, this is a pumper)
Last edited by Gary Cee; Oct 20, 2011 at 12:11 PM. Reason: Disregard
Aug 23, 2011, 10:41 PM
Gas Only
Fokker DII's Avatar
I have a sweet running Saito 14FG in a Pulse 60XT.
It started and ran very nicely at 1 turn 20 minutes on the hsn, I did not touch the low speed until I had run a gallon of gas thru it. For the first 1/2 gallon it spit a SMALL amount of black soot onto the tail of the plane.
After the break in I started leaning out the hsn with the tach for max rpm minus 100. After a gallon I leaned the low end 1/8 turn at a time until the transition was smooth. The high speed needle ended up a bit over 1 turn out.
Into the 2nd gallon the engine started to run smoother and idle slower.
Get rid of the Coleman fuel and run it on mid range gasoline with synthetic oil at 20:1 and it will be clean and smooth.
I love mine.
Aug 23, 2011, 11:08 PM
Registered User
Thanks for the comments. An especially useful post thanks Fokker.

I will try unleaded petrol - thanks for the suggestions.

The Australian agent for Desert Aircraft is close to me, and I see they recommend Red Line 2-stroke Racing Oil for their engines. Will give that a go to since the Evolution oil that Horizon Hobby suggest is just not available here.

Thanks again.
Aug 23, 2011, 11:22 PM
Registered User
fiery's Avatar
Try some Motul 8000 off-road cycle full synth 2 stroke oil from your local Sper Cheap Auto. Not cheap, but as good as anything out there IMO.
Aug 24, 2011, 04:32 PM
Gas Only
Fokker DII's Avatar
Saito reccomends full synthetic oil because it has less tendency for carbon build up on the exhaust valve. Any good quality synthetic should be fine.
Enjoy your engine.
Aug 26, 2011, 07:56 AM
Registered User
Well - I can say that the Red Line 2-stroke Racing Oil sure gives a different result!

There is now no "oily liquid inky gunk stuff" dripping out of the muffler. Just a light fine spray of "dry but slightly sticky" carbon like film deposit left behind on my run-in stand. At A$30 for 473mm it is expensive, but seems like a good match.

And now using premium unleaded too.

But I'm still getting raw fuel collecting around the carb inlet bell. I don't think that can be normal.

I've placed a brief video on youtube:

Saito FG-14B Running In - Rich or Not? (2 min 5 sec)

I have noticed that if I pinch the fuel inlet tubing, the revs pick up immediately.

Fokker - exactly what do you mean when you say "After the break in I started leaning out the hsn with the tach for max rpm minus 100"?
Aug 26, 2011, 02:22 PM
Registered User
NefariousRC's Avatar
Originally Posted by brw0513_2
Fokker - exactly what do you mean when you say "After the break in I started leaning out the hsn with the tach for max rpm minus 100"?
When you lean out the high needle revs will increase. When the high is too lean revs will slowly drop off after hitting the peak. Basically, you slowly adjust the high until the rpm stops increasing or slowly drops and the back off a little.
Aug 26, 2011, 04:42 PM
Gas Only
Fokker DII's Avatar
I meant to set the high speed needle to max rpm at WOT with a tachometer, then turn it out (rich) until you get a 100 RPM drop. This is a very small amount of needle movement.
Do Not run a gas engine overly rich like we do a glow engine or it will foul the plug and build carbon.
Aug 26, 2011, 11:18 PM
Registered User
Originally Posted by Fokker DII
set the high speed needle to max rpm at WOT with a tachometer, then turn it out (rich) until you get a 100 RPM drop
Now it makes sense to me

I presume there is no need to adjust the low speed needle from factory settings?

Last edited by brw0513_2; Aug 26, 2011 at 11:20 PM. Reason: Still can't spell.
Aug 27, 2011, 04:51 AM
Registered User
fiery's Avatar
Negative on that one, like the high speed needle, the low speed needle is almost certain to need some adjustment. But, if you are happy, make sure you take a reference so you can get back there if performance after a change deteriorates.
Aug 28, 2011, 05:47 PM
Registered User
Use regular unleaded, not premium. Try and get the engine running OK andleave the low needle at the factory setting is easiest for run in. You will eventually need to tune the low end (for fine tuning) because it influences about two thirds of the throttle. As a general principle, it is betterto go a bit rich on the low end as this ensures reliability as well as allowing you to go a leaneron the top end.

The engine takes several hours to properly run in before you can really fine tune it. My advice is just to get it running reliably and don't worry if the top end is not perfect. Fly it to run it in and will gradually tune better. Make sure there are absolutely no bubbles in the fuel line feeding theengine.

In my view, the most reliable way to tune is by pointing the engine to the sky. Too lean and it will just quit. Too rich and it will start to stumble.

I'm not sure about the fuel leak. Is the tubing/nipple connection tight? If you are using Tygon, you usually need to put a tightener around the connections.
Aug 28, 2011, 06:23 PM
Gas Only
Fokker DII's Avatar
Mine spits a bit of fuel around the carb intake area. I have heard that a velocity stack cures this, but have not installed one. I squirt a bit of cleaner on it after a day and it is good to go. I am used to cleaning up the mess from a glow enging and find the gasser to be a GREAT improvement.

Yes, you will need to tweek the low end needle a small amount but not until you have run it for a while and you have leaned out the top end as it breaks in. You will notice the transition needing a tweek when the time comes..
The Saito manual reccomends 91 octane gasoline.
Sep 17, 2011, 09:07 AM
Registered User
I had the chance today to run-in the Saito FG-14B some more. Last time, it was still stuttering and not revving all that cleanly but I put that down to still being deliberately rich. So today I planned to lean the high needle by 2 clicks and do some more running in.

Well after 2 clicks leaner on the HSN it ran like absolute rubbish. Coughed and spluttered. Wouldn't idle below around 3500rpm. Wouldn't rev cleanly. Returned the HSN and no different result.

Previously, when I pinched the fuel delivery line it would hold the set revs for a short time before speeding up then quitting when the fuel ran out. But today that didn't happen.

I ran out of daylight soon after this.

When I looked at the engine later I noticed the spark plug lead may not have been seated all the way down. I had taken the plug out earlier in the day to check its colour (black and sticky) and gap (0.45mm which is in the middle of the stated requirement). I'll try again tomorrow to see if this was the culprit.

The other thing I noticed is that the carb "barrel" (i.e. the bit that moves in and out of the carb body when the throttle arm is moved) seems to be a loose fit in the carb body. When the carb butterfly is more than 1/2 open, the carb barrel seems to wobble a bit. Raw fuel doesn't leak out, but I can see liquid fuel is present around the barrel. Is this normal?

The other question I have - Is it possible to accidentally damage the HSN needle or its seat by turning it too forcefully to fully closed? I didn't mean to do it, but the steel wiper that keeps the HSN in position is very stiff to overcome and sort of hides the feel of "full closed". In trying to find the full closed position, I didn't realise it was fully closed so tried to turn the needle a bit more. I'd hate to think I've done something dumb.

Good advice appreciated.

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