JettPilot

My Feedback: (6)

That is the Australian version of the .82 GK, everything is backwards when you are below the equator [sm=spinnyeyes.gif]. Here is a picture that will make you feel more at home

Hobbsy

My Feedback: (102)

My test of the Saito 2.20 crankcase pump and large carb option was a bust. When using the supplied pump back plate 7,700 rpm was all it would make regardless of the prop in use at the time. An 18x8 Mejzlik, 18x8 Just Engines Carbon Fiber prop, Just Engines Carbon fiber 20x6 all made 7,700, 7,800 was do-able at absolute peak but that is all. I did stumble onto something though, using the big carb with a Cline or IronBay regulator saved the day.
Fuel PowerMaster 15%/18%--80/80 blend.

Stock carb
JE CF 20x6===7,950
JE CF 18x8===7,950
Mejzlik 18x8==7,800

Optional larger carb
JE CF 20x6===8,590
JE CF 18x8===8,500
Mejzlik 18x8==8,450

The larger carb has a very good 1,875 rpm idle that I believe is actually useable where as 2,100 is iffy with the stock carb. I cannot explain the low rpm when the pump backplate is in place, I of course removed it to run the Cline and the IronBay.

Incidently I did a first today I blew the seal out of a Fox Miracle plug when I got the 2.20 a little lean. It probably saved kicking the prop loose. Using the supplied needle valve for regulating the tank pressure was an excercise in frustration, it would take much trial and error to hit the right combination, in my setup you see, the minimum I set it at did the job. It was fun anyway.

semi_conscious

I am about to rebuild a Saito FA-91 that went through a fire. It didn't get hot enough to melt any rubber seals but the bearings, cam, crank, piston ring, and valves are very rusty. I presume the heat might have burned off the oil protecting these metal surfaces allowing them to rust severely. The cylinder is in great shape and the motor appears to have very few hours on it. My questions are concerning a few things I haven't been able to clear up through searches on RCU.

If I replace the valves, will I need to seat them by lapping with toothpaste or rubbing compound? The motor looks like the older version with inserted one piece brass valve guides/seats.

Do I need to deglaze the cylinder wall for the new piston ring to seat? If so, would 400 grit wet/dry sandpaper work for this? or #000 steel wool?

Is .004" the correct gap when adjusting the valves?

And last but certainly not least... what is the best way of determining TDC when installing the cam? (I already have a tool for holding the cam in place...it's the crank I am more concerned with)

As I understand it..being even one notch off on cam timing will result in a bad running engine.


This FA-91 is going to be so sweet in my Skybolt thats been hanging on the wall for a few years just begging for a 4-stroke.

Thanks to everyone in advance

w8ye

My Feedback: (16)

Getting the crank on Top Dead Center has not been that critical for people. Just have the crankpin at the top.

There's 24 teeth on the crank and 48 on the cam. One tooth off will be 7 1/2 degrees.

The valves are set .0015 to .004"

The valves should be OK if they are not stuck

Kmot

My Feedback: (24)

Hobbsy again?

Hobbsy

My Feedback: (102)

Shore nuff, it's me. One thing I did not mention is that the 2.20 runs the smoothest with the 20X6 prop, I was hoping somebody would say or at least speculate why the 2.20 seemed to hit a wall at 7,700 rpm with the pump backplate in place no matter the prop.

plasticjoe

My Feedback: (22)

Hey there,

I have a Saito .91 in a Goldberg Ultimate bipe. I have a 12/7 prop on it and have adjusted the valves in it like I have read here in the thread. I am having problems with the transition. It idles rather nicely low RPM, have not tached it but it's a nice idle that does not pull the plane on a smooth surface. When I open it up to full throttle I lean it out until I hear it lose RPM's then return it to the full RPM setting, then richen it about 1/4 turn. There is a nice trail of exhaust smoke. But when I take it back to idle, let it idle and then transition quickly up to full, it bogs and dies unless I jockey it up to full. That is as it bogs, lower the throttle and let it catch itself and then slowly raise the throttle. I want tune out that bogging. Any suggestions ? Also what would be an ideal prop to run on that combo ?

crtmmac

My Feedback: (12)

Hi. I read about removing the cam followers and inserting a special tool onto the hole to hold the cams in place while re-assembilg the cam assembly. No problem, except how do you remove the cam followers. They seem to be free to move, but shaking or tapping doesn't free them from their position.

Thanks
crtmmac

w8ye

My Feedback: (16)

I've always shook mine out.

Some of the engines have mushroom tappits and you have to take the cam out of the cover to remove them (120, 150, 180, 220)

JPal101

My Feedback: (32)

PlasticJoe

Sounds like your LS setting is to lean, set your HS as you have done, get your highest RPM under full throttle then richen a bit, then set your LS for your idle

rfan_1

My Feedback: (2)

That Saito 40 will go nicely into a Model Tech Extra 300. It will fly that plane quite well. OR, you could put it into the new Hangar Nine Ultra Stick 25e, after replacing the firewall with a thicker one. I've done them both.

Did you want to sell it?

RFan_1

hrrcflyer

Hello Club Saito,

I started out with a Saito 100 in a 60 size Ultrastick (The best enging/airplane combination I have had to date). I have since sold the 100 to my brother to put in his Dragon Lady. I presently have only 2 Saito's. A 180GK I an puttintg in an Ultrastick 120 Lite and a 125GK I will be putting into a 60 size Carl Goldberg Ultimate Biplane. I hope this qualifies me for the club.

What will my membership number be?

Thanks and good flying...

David

Hobbsy

My Feedback: (102)

W-man, this .30GK is an exceptional one, a few hundred rpm stronger than my old one. It turns a Graupner 10.5x6 at about 9,100 and this 10x5 at the numbers you see on the tach. Oops doesn't show up real well, 10,948. This is on PowerMaster 15% fuel.

Iflyglow

My Feedback: (79)

The sweet little .40a has a new home with Hobbsy now.

JettPilot

My Feedback: (6)

That is th cutest little Saito I have ever seen, wish I had one Where did you get it and now much ? How big/heavy is the airplane you are going to put it on ? Does it run and idle well ?

JettPilot

JettPilot

My Feedback: (6)

William Robinson,

Where are you, this thread is just not the same without your expert advice [] Some people were talking about the smaller throated carb 56-s models running a little better than the wide throat models we have here in the US. What do you think about putting a restriction in the throat of the carb to acheive the same effect ? I could easily build up the throat in mine a little using JB weld

Suggestion number two is way beyond what I have the tools to do, but it would be great of someone reground the cams of Saitos so that they were a little more mild and would run more smoothly I know I would buy a smoother running cam for all my saitos even if I lost a little off the top end.

JettPilot

Hobbsy

My Feedback: (102)

JP, I got that one in April from my LHS "Apex Hobbies" in Tazewell, Va. about 362 miles from here in Colonial Beach, Va. I think it was 184 bucks. My old .30 has been on two Sig LT .25s and inverted on a ModelTech Cub. They throttle very well.

Thanks MM37, I'll run the .40a in and post some numbers here, I hope it is as impressive as the little .30.

scratchonly

Hobbsy

I noticed in your pictures (I think) that your 80 had a velocity stack. I jury rigged a 7/16 x 5/8 brass tube with a rolled edge and attached it with LPS aluminum epoxy heated to cure at about 120 degrees F. Tried to pull it off and couldn't.
Set up my engine on test stand inverted and started to adjust. Didn't change the idle screw much but the HS was rich. I maxed out the HS at 9400 on a 14x6 apc, tuned down to 9000 and got a 2500-2800 reliable idle with a great transition. I could make the HS rich down to a blubbering 6000. I attribute the ability to get rich to the stack. Do you agree? Still have not received the upgrade but will install it when/if I get it.
Stack held firm thru all tests. I think I'll leave it on.

Thanks again.

Hobbsy

My Feedback: (102)

Scratch, those are good high numbers but it should easily idle at about 2,100 to 2,200, I'll bet it will with the new spraybar. Are you able to post a pic?, Thanks

scratchonly

Hobbsy

Sorry, no. I am a model plane nut, not a computer nut. I rolled the end by pounding On the othe other end with the rolled end sitting in a steel block. The 7/16 tube is about a millimetre larger than the carb. I use LPS aluminum epoxy because an engine repairman told me it is superior to JB weld. I have no idea if this is true. Heating epoxy will make a stronger bond. I think if you were to aneal the brass by heating to red you could make a nice flare by hitting a small ballpean hammer held on the end I tried this on the unanealed brass and it split. I made about a 1/8 epoxy fillet.

blw

My Feedback: (3)

JettPilot- I'm not sure the .56F being a better engine. It has less power.

crtmmac

My Feedback: (12)

Thanks. Mine won't shake out. (It's a .65). how can you remove the cam? Does the cam axle drive out with a center punch? Thanks for your advise - it's a great help.

colin

Hobbsy

My Feedback: (102)

Scratch, I gotcha, I made one for my .80 just like this one I made for the 1.25.

RVM

Some questions:


I got a great idle of 2000-2200 on my Saito .91, and max RPM around 9450-9500. I'm using 20% nitro, 15% oil fuel, not too high above sea level and a 14x7 APC. The numbers seem good, but it "wobbles". What I mean is when I try to set the top end needle, the RPMs will waver from say 9250 to 9500 (without touching the engine), making it really hard to set. The same with the low end. A guy I know said it might be the fact that this particular prop has hit the dirt quite a few times. There is a whizzing sound, which fades in and out, when the engine is above about 8500 RPMs. Frankly I'm surprised this prop hasn't broken. I've never had any APC survive smacking the dirt (and this is pretty hard dirt), much less survive it 3 or 4 times. Also, I noticed that sometimes when I make a change on the HS needle it tends to immediately kill RPMs, unless I throttle down and back up. I know it takes a few seconds for a 4-stroke to react to a needle change, but I'm finding that the change is either immediate, with instant RPM loss anywhere from 200 to 700 RPMs, or that no change ever happens. Occassionally after a needle adjustment I can pinch the fuel line and the engine will adjust in what seems a normal fashion. Anyway, I've checked the fuel flow and the plug and all seems well. What could be causing this wavering?

When going from an idle to full throttle, my engine has a slight gurgle to it. I've tried richening up the low end, and that didn't help. It completely dies if I go much leaner than it currently is, so I know that's not it. What can I do to smooth it out?

My second question is easier. Is any air tool oil suitable for an ARO, or is Marvel the only brand? I guessed that it didn't matter, so I've got a bottle of Kobalt air tool oil from Lowe's. Also, is any ATF suitable for an ARO?

What is the "redline" of a Saito .91 and a 1.00? What is the best RPM range to prop them, generally?

Thanks!

RVM

oops