N1EDM

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Hi guys,

I'm pretty certain that Santa is going to leave a Saito .72B under the tree for me. I've had larger and smaller Saitos but never a .72. I plan on mounting it inverted in a H9 J-3 Cub. Is there anything that I should know about it?? I'm planning on using 10% fuel so I think perhaps a 13x6 prop, maybe??. Who has experience with the .72 that they'd like to pass along.

Thanks,

Bob

jb86

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I run a 13x 6 on a cub
14x4 on a profile 3d
10% wildcat fuel
rule of thumb I've followed
for an inch of diameter change pitch 2"
turns both at just about 10k
plenty of power

N1EDM

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Thanks for that jb86. What's up with the "B" model. Does anyone know how this differs from the .72 "A"???

Bob

Hobbsy

My Feedback: (102)

Bob, the B is the new crankcase style like picture #1, picture #2 is the old style. In the case of the .72b, it also has a metal back plate.

mxzmadness

my fg 21 4 stroke gasser in the ultimate

Cougar429

My Feedback: (3)

hsukaria, not sure if anyone answered your question on the 91 prop recommendation, but for ground clearance I run MA 13/8 3-blades on both the 91 and 100 to good effect. For scale and to clear the large cowl, the second 91 in the AT-6 on the build table now will start with a JZ Zinger 14/8 wood prop, (my normal procedure is to start with wood till familiar with ground handling and landing) and likely then get an MA of identical specs.

To be honest other than those mentioned I have only run Graupners. Although they seem to look nice, their performance seems identical or lower than MA. Have not yet bolted APC to any 4-strokes. Look too far from scale for my eye.

marksp

My Feedback: (9)

The last few flights with my Saito FG-33R3 have ended with dead sticks. Engine starts and runs fine, but after a few minutes of flight, temp climbs (on-board telemetry) and ultimately engine dies. After playing with various baffle systems, I decided to reset needles to closed position and start from factory settings. At this point, I realized that the low speed needle [referred to as "slow speed needle" in manual] was super lean! Manual states 8 turns from closed, and needle was 6 - yikes! It is evidently moving/vibrating while running.

What causes this and more importantly, what is the solution? Engine has less than 1 gallon of fuel.

Thanks for your guidance!

Cheers

spaceworm

Hi Hobbsy, are the internals all the same between the "A" and "B" cases, as I understand they are with other "B" cased engines? I need a new case for my FA180 and was thinking of upgrading it with the "B" case. Is all I would need the case and cam cover? Thanks. I am thinking of adding an ECDI, but still running it on glow fuel. Whadya think about that?

Merry Christmas to You and Yours.
Sincerely, Richard
Cub Brotherhood #187; Sig 1/4, H9 100 inch (Gen 1), GB Anniv Cub
Club Saito #635; Saito 56, 100, 120abc, 130T, 180
Kadet Brotherhood #96; Mk 1 Kadet, Kadet Junior,
Sig Kougar, Sig 1/4 Cub, Sig 1/4 Spacewalker II

N1EDM

My Feedback: (2)

Thanks, Hobbsy. I can see the differences. Other than the backplate, I wonder why they felt the need to redesign the case? Thanks again for the information,

Bob

Rock81

Ok, I bought my first Saito tonight but I messed up, or at least I'm pretty sure I messed up. It's a fa-62aCL. Can this be used in an rc plane, will a carb change be need?

earlwb

Yes you can use it in a RC plane. But without a throttle, means you will fly it full throttle though. You can setup a engine shut off device either as a fuel shutoff to kill the engine on command. But for RC with a throttle, you will need a carburetor for it. That may require a intake manifold too.

Hobbsy

My Feedback: (102)

Bob, I've never seen a reason given for the change, maybe just a cleaner looking product. I saw where someone mentioned that the box might be stronger and more stable.

Richard, w8ye or SRTelemaster might know if your inner parts will slip right into the B case. I don't see why they wouldn't. I have three converted to CDI right now. A high compression .80, a 1.00 and a high compression 1.50. I don't know if they have more power yet, but it is safer to run them leaner. Adrian at C&H Ignition will steer you in the right direction.

PS, Richard, do you ever get down this way these days. I'd like to meet you in Fredericksburg at Shoney,s and treat you to lunch.

N1EDM

My Feedback: (2)

Thanks, Hobbsy

Rock81

Thanks, that's good news so new carb and maybe intake and in business. You think the carb for the fa-62a and intake will do the trick?

SrTelemaster150

Generally, the only difference in "A" & "B" engines is the case, cylinder & the cam housing. The cylinders will interchange on either case & only differ as far as cooling fins with the "B" having more fin area. this is most likely so the casting can be used for FG versions that neeed the extra cooling.There are no geomtry differences between the "A" & "B" cylinders. The only parts that are exclusive to each other are the case & cam housing. All other parts interchange.

With big blocks I know this is true & a quick check of the 72 part #s seems to indicate the same.

hsukaria

Thanks Cougar429. I was worried that a 13x8 2-blade would be too small a prop for the 91. I would love to put a 13x8x3 prop, or even a 12x10x3 if it exists (I have a 12x6x3 -too small) on the Ultimate bipe, after all, the real version runs a 3-blade. The only trick is to pay for the 3-blade spinner for it. I might have to start being extra good, maybe Santa will give me a 3-blade spinner?

N1EDM

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Thanks for clarifying that, SrTelemaster150

Bob

blw

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The 72 is a great engine. The APC 13x6 is perfect made for it. Wait until you hear it at full throttle after about a half a gallon of fuel. It is the best sounding Saito at wide open throttle, imo.

dixmyth

Yes, I do. I will give you a heads up, probably in early Jan 2015. Thanks for the invite.

The very best to you and yours.

Sincerely, Richard

Corsair2013

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Guys,

I also have a almost new Saito 72. Couple of questions - where is a good place to get an ALUMINUM replacement throttle arm? I hate the plastic one.

Also - will I have any issues if I put in a remote high end needle valve? Where is a good place to get both items along with nipples and parts if I need them?

Thanks

Keith

Hobbsy

My Feedback: (102)

The metal arm will be hard to come by since it's the early style. If you can get hold of an MDS remote needle it would be ideal, they don't leak and will stand the pressure of a Cline regulator system. Since fuel can neither be stretched nor compressed it doesn't matter where you place it.

Cougar429

My Feedback: (3)

From what I remember, there are some internal parts differences in that the cam has a "Quiet Ramp" profile to slow down initial lifter rise and the valve seats in the head are actual machined inserts rather than the earlier electro coating over base metal. In the earlier version it was advised NOT to try and polish or dress out any seat imperfections.

The case vent was also moved from the back cover to below and opposite the cam, presumably for better lube and scavenge. On my first 91 I tapped the fitting into the case in that location and plugged the rear cover. Did not notice any difference in performance or parts life. However, since that motor spent the following 45 or more hours after that mod at predominantly half throttle, difficult to tell if the design came into its own.

I do not think this would prevent the newer parts fitting earlier gen motors.

Corsair 2013, The older arms were steel, not alloy. If you can measure the bore size or if someone can confirm the compatibility, I think I have one from an 82-91 that we can trade. I prefer the plastic anyway as the added thickness makes tapping for ball links a bit easier.

N1EDM

My Feedback: (2)

Thanks for that, blw & Cougar

Bob

Rock81

Thank you, I was able to do some research to discover the a and b use the same carb and a, b, and aCL all use the same manifold. So I'm in business, it's going on an escapade. Can't wait.

hsukaria

I have owned the Escapade 40 for about 6 years now, great plane. I recently have been using it as a flying test platform. I have used 5 engines so far with a sixth one in the works. I have also used it to test radio receivers. I think the Saito 72 would be excellent on that plane. I recomment that you add triangle stock at the firewall and a crossbrace between the cowl cheeks. They vibrate a lot and will crack the glue joint.