w8ye

My Feedback: (16)

As long s it doesn't pull the plane, I wouldn't worry too much about it.

The engine should be able to idle at 2500 with no problem

nitrobeast

I didnt think it was a big deal. With a 13x6 prop how do you know what the max rpm's would be? Do you keep leaning until the rpms start to drop and then richen it some?

Thanks

w8ye

My Feedback: (16)

That is correct

Tbone4life

I have read alot of different sites about the Saito 100, and most of them say that I'm doing good to get my Saito 100 to idle at 1800rpm with a 14x8 MasterAir Screw Classic. I just think it's a bit too much engine for Ultra Stick .60, because it pulls the plane almost faster than I can walk at idle.

Maybe I should try an APC Schimitar type prop instead?

Any idea's?

blw

My Feedback: (3)

Are you saying that the plane rolls when you are at 1800 RPM at idle?

Tbone4life

Yes it does.

Its a Hangar 9 Ultra Stick .60 with Quad flap setup.

w8ye

My Feedback: (16)

Change to a 15 X 6

Tbone4life

A 15x6 MasterAir screw classic or an APC sport ?

I just put 3 1/4" wheels to get it off the ground for a little more prop clearance. If it ever quits raining here I'll try it and post the results.

w8ye

My Feedback: (16)

Not so sure the 100 will pull a Classic. But if it will, the wide blades should give the plane good vertical?

The "K" series is what I had in mind?

XJet

I've found that the Scimitar series from MAS actually give more thrust than the K-series.

I'm running a MAS 14x6 K-series on my Saito 100 in a Mojo 60 profile at the moment and I *really* notice the lack of thrust when compared to the APC 15x4W or the MAS Scimitar I was using previously. (I run just 10% nitro so a 15x6 is just a little big for my 100).

The K series are best for making lots of cool prop-noise when you start hitting 10,000 RPMs with anything 14-inch and over. The Scimitars are quieter and much better at turning HP into thrust.

The "won't stop moving" scenario is the only real downside of trying to use a 4-stroke on a *fast* airplane. In order to get a decent top speed while keeping engine RPMs around the 10K mark, you've got to use a snot-load of pitch. This means that even at idle, your prop is creating quite a fast slipstream -- quite often too much to stop it from moving forward and making it rather difficult to slow up on the final approach.

What we need are variable-pitch props for 4-strokes!

RVM

They are made by one or two companies. They're relatively heavy though.

Heritage rider

My Feedback: (2)

This post is about a significant change in my Saito 100 Low Speed needle valve setting.

This is my second 100, the first being destroyed in a crash. It has about 2 1/2 gallons of fuel through it. Am using YS 20 and sometimes heli 30% for max power. I broke it in right by Saito's book and ran a few more tanks before I mounted it on my plane. After the 1 1/2 gal point I adjusted the valves. Put it in the plane, changed the muffler to a Slimline Pitts and re-adjusted both needles. Used a tach, line pinch, my ear and the smooth transition from low to high speed. It ran really well and ended up about 1 3/4 out on HS and 1 1/2 on LS needle (approximately). It is mounted inverted. It is in a World Models P-51 at the moment so has to be hand started because the spinner is about the size of a gallon bucket!!

Yesterday, made one flight. Started easy, landed great because I moved the CG back 1/4" from spec. Made some more radio adjustments and fueled to fly again. WOULD NOT START!! Kicked, backfired etc. Found a split fuel tube on the supply line (using 3 line tank). Replaced the tube, still would not start. Kicked over a couple times if I got it wet (with engine right side up).

Went home and tried again. Re-did all the external plumbing. No good. Removed the tank, even though it tested fine and replaced all the internal plumbing and cleaned it out. Yes, it has a filter. No start again. Of course, I changed the glow plug twice. They all worked fine but changed them anyway. No start. Took it out of the plane, removed the carb and both needle valves, flushed the carb, the engine with alcohol. Found no dirt in the carb. Oiled everything with after run oil, put it all back together. Put HS at 2 1/2 open and LS at 2 open. NO START. It would prime just fine but would not start.

Then, I put a long fuel tube (I am now on the test stand for all of this) so I could stress the fuel drawing a bit and easily see if the fuel was drawing to the engine. Wide open throttle, NO IGNITER and electric starter and could see the fuel drawing very nicely through the long fuel tube. Emptied the fuel tube and set the throttle to about 4 clicks and it drew nary a drop.

So, I just kept opening the LS valve until it drew some fuel with the electric starter driving the engine. I had to go to almost 4 turns out for this to happen. I went back to the normal length fuel tube, primed it, opened the HS to 2 1/2 turns and it fired right up with the LS at 4 full turns open.

I then went through a normal tuning process: HS first with my tach, LS leaned until it died on transition and then about 1/8 back so it idles very smooth and transistion is really good. HS again. The adjustment process went exactly as it has before with this and my other Saito engines (just 3 so far), it just is happening at 4 turns out instead of 1 1/2.

So, I am about where I was before on the HS but the LS is about 3 3/4 turns open.

I did not disassemble the carb escept to remove the needle valves when I cleaned it. I checked the valves again although I can't see much relationship to the needle valve settings (I could be wrong). I could not find anything loose. The nut and the barrel on the HS side are tight. I am getting 9300 plus RPM with a MAS 14X8 classic prop. That is what I had before. Idles smooth but don't know what the RPM will be because I have a mechanical linkage on my test stand and it is impossible to give it the fine adjustments at idle. Sounds and runs like a Saito again; GREAT.

I would sure like to understand this a bit before I put it back in the airplane, cowl on, etc.

So the question is, what could have happened to change the LS idle adjustment so much??

If you think you know I would love to hear from you.

Thanks

RPM1

My Feedback: (2)

Well if anyone was hanging on a response from my problem, here is the resolution. The valves were not an issue they were set fine. I convinced myself that there was too much rotating mass on the front of the engine with the 14-6 three blade Master Airscrew prop and the 3 1/2" Tru-Turn spinner. The spinner had a solid back plate and was quite heavy. So anyway, I gave the spinner to my neighbor who owns a machine shop and he cut some holes in the back plate (away from anything critical). I know that Tru-Turn frowns on this but I put my trust in my neighbor. After I got it back, I checked the balance, it was balanced perfectly. I fired up the 100 today tweaked the high speed a little and now it runs at 9400 nice and cool and transitions great. Idles at about 1800 rpm all day. So I guessed correctly and all is now fine. Thanks to everyone for the suggestions.

spec36

would it hurt the performance on a saito 72 to extend the exhaust to keep off my plane (ie long tube from front to back of plane like 19 to 20 inches) ?
it is soaking my servos anyway I turn it.

this is on a v2 katana profile
thanks for any help

w8ye

My Feedback: (16)

Four strokes are not as sensitive to exhaust back pressure as are two strokes

You can add an extension with little degrade of performance

spec36

thanks for the help
but what would be good to use and stay light for 3d flying in your opinion?

w8ye

My Feedback: (16)

H9 Twist 40 would be cheaper fun?

spec36

I already have the v2 maybe next i will try one .. I was looking for what kind of tube to use that could take the heat.

thanks for the help in the past its been a long time ago but this 72 of mine has been great and on it's
3rd 3d plane now and runs like a charm

p.s. I don't know what number I was in the club tryed to look but alot happen while I was gone.
I must go back and see what good stuff I can learn .

einarak

hi, i have 56 saito that needs new bearing and a small fix, where can I get spares?

w8ye

My Feedback: (16)

Get your bearings here . . . .

http://www.rc-bearings.com/

Hobbsy

My Feedback: (102)

Jim, Geri bought me a new Saito twin yesterday, I'll be breaking it in Wednesday.

I have two 20x6 props to run on the 2.20, a Master Airscrew Classic and an APC, I should get to that tomorrow.

swixtt

Wondering if you guys are using any 3 blade props on a Saito 100. what size are you running and what is it turning at? right now i'm running a 15x6 2blade. air frame is an Air Tractor AT502 Spray Plane.

thanks for any info...

w8ye

My Feedback: (16)

One guy was running a 14-6 three blade.

A 13-8 three blade should work well also?

RC Specialties

swixtt,

I have run a MAS 14x7 before and my 1.00 turned it in the low 9's. It was on a H9 Corsair and it flew well. I switched to a 14x8 APC and liked it better.

Jim

tomcraig

I have 3 Saito's 82, 100 & 125 all run absolutely great and now after reading for hours i would like to become a member of this club
Thanks