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May 19, 2019, 08:49 PM
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Saito 56

Hello and thanks in advance for any help.
Bought a used Saito 56. Put it in a test stand and primed with finger over carb throat. Primes right away and fires but just seems to run out of fuel, right away. And dies.
I donít see air in fuel line when this happens.
Donít think it is tank setup because it works for other engines. Tank is a little lower than carb however.
I am total newbie to 4 stroke engine.
Probably operator error,

Thanks again for any help.
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May 20, 2019, 02:16 AM
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Gahspidy's Avatar
I’m sure others with more experience will chime in, but since you didn’t mention it in your post are you providing exhaust pressure to the fuel tank? If so, perhaps you should reset the carb needles to the factory specs which can be found in the Saito manual.
If the glow plug is the one that came with the used engine, try changing to a new plug. Just some ideas
May 20, 2019, 04:55 AM
Registered User
The saito 56 is one of the best handling 4 strokes in my opinion, I have 3 of them.

Sounds like the main needle needs to be wound out a bit, try 3 turns out to start with, should be slobbery rich at that, gradually turn it in to achieve a good top end.
May 20, 2019, 06:11 AM
Registered User
Cherokee Flyer's Avatar
I would also suggest you make sure the low side needle is open enough. That to is in the manual. Since you are new to 4 strokes, I would suggest that you set the top end with a tach, as they have a different sound than a 2 stroke. They run very well with a APC 12/6. As said before, they are a sweet engine. Would also suggest you check the valves settings since it is a used engine. Again see the manual or get a friend who is running 4 strokes to help you.

May 20, 2019, 08:54 AM
Registered User
Thread OP
Thanks for replies.
Low speed needle did seem turned in to far. I think I checked valves when I got motor, but will check again.
Not sure when I can retest as it is raining and I need to get to work on a busy week.

Thanks again. I’ll let you know if I get it going
May 20, 2019, 01:31 PM
Registered User
Cherokee Flyer's Avatar
If you don’t get it to run, I’ll bet there are 20 guys who will be willing to take it off your hands!

May 21, 2019, 07:18 AM
Engine man
dmrcflyr2's Avatar
I'll tune it for you and send it back for the cost of shipping each way.
May 21, 2019, 07:44 AM
Registered User
Thread OP

thank you for the offer. And I may take you up on it some time.
I am not in a hurry for the engine right now so will at least give it one more shot.
And again thanks to everyone. Not hardly anyone around here running Saito's
I did reset valve and turn out low needle. Busy week but if I get a chance will try to fire it up.
May 21, 2019, 08:14 AM
Systems Test Engineer Amateur
Gary Cee's Avatar
Hard to beat lessons learned by doing,
May 21, 2019, 10:18 AM
Registered User
Thread OP
Hey hey,
Got it running. Ran it for awhile rich just for fun, to hear it.
Thanks to everyone. My guess is the problem was low speed needle turned way in. Seemed like a fuel problem from the get go. I also raised tank height and set valves, exhaust was a little open, but I really don’t think that was problem.

Thanks again, and I may post rpm numbers when I get time to really tune.
Thanks , thanks again viewers
May 21, 2019, 12:36 PM
Systems Test Engineer Amateur
Gary Cee's Avatar
Yep, a common part of the Saito "learning curve".
Also seen situations where "Can't get it to run rich at high speed" is the complaint.

... Same cause
May 22, 2019, 01:25 PM
Registered User
Thread OP
So, turns out I had too small prop. Thought it was 12-6. Actually 11-6.
Didn’t realize till 11000 rpms showed on tack and wasn’t leaned out all the way.

So we will have to get corrected prop size.

One other problem is throttle stop screw keeps coming loose. Will try thread lock. If anyone has a fix for that , let me know.

May 22, 2019, 02:34 PM
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Cherokee Flyer's Avatar
Doesn’t the screw have a spring on it? Did you balance the prop?

May 22, 2019, 06:36 PM
Registered User
Thread OP
Yeah, screw has spring. I even stretched spring for more tension.

Prop was balanced but undersized. So we will try all over again when I get a proper propeller.

It’s been fun. I really don’t have a plane for it. Unless I want to take a motor off.
Jun 07, 2019, 08:08 AM
Registered User
Thread OP
For what it's worth, I ran the motor again with MAS scimitar 12x6.

It gets up to 10,000 rpm. It might go higher, but when it gets that high I get scared and richen it to about 9500 and leave it. That is at 5000 feet elevation , 15% nitro byron.

It spits alot of fuel out of the carb, I dont know if this is normal, but I am going to order the venturi thing. If I ever mount on a plane maybe sideways or inverted could help. I hope to mount in a Cub, sideways, but that is not something that will happen real soon.

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