Garthwood

W8YE / Jim ..............My procedure to defuel is I keep the nose down to move the fuel to the front of the tank where the vent/fueler/defueler is located to the front and facing down. I then start up the Saito and run off whatever fuel is left until the engine stalls. Perhaps some fuel is still being left in the tank ? When I come to fuel up with an empty fuel tank (assuming that it was emptied) the first few turns of the fueller, fuel comes out of the muffler. Maybe like you said some fuel is being left inside the lines, but how is that possible if the engine quits after the carb line has emptied ?. Once it reaches a point during fuelling up it stops ejecting from the muffler, and it will continue to fuel up without any other problems. Engine runs like a dream with no stalling, start up are instant without priming.

I'll probably have to remove the bottom wing and cowl to check the lines and see how far down the pressure line is going to the bottom of the tank.

Thanks guys.

Charles.

w8ye

My Feedback: (16)

Charles,

Sometimes there is Fuel and /or oil left in the muffler after running the engine.

If you have the pressure tap on the muffler on the bottom side, some of this oil or fuel will be inside the pressure line.

Safebet

My Feedback: (12)

UPDATE:

I removed the valve covers and both valves are operating. However, the exhaust valve is about .030. Gap way too much. I, also, removed the glow plug and poured some oil in the cylinder and rotated the prop with the throttle both open and closed, in case I had a "dry" cylinder.

There is very slight compression now. I did look thru the glow plug hole and the piston is moving up and down. I am going to get
some assistance at the club, today from some of the more experienced 4-stroker's and adjust the valves. Hopefully, this will
resolve the problem. Could the fact that the exhaust valve gap is so wide cause this? Doesn't seem likely.

What befudles me, is the fact that it ran so well during the flight, taxied right up to the fence, idling great, he killed it with
the trim switch and then 5 minutes later sitting on the table, no compression.

I do love that engine. It ran so well and sounds so good and pulls that Cub just right at 1/3 to 1/2 throttle.

I suspect I had it tuned a little lean. I am going to be sure that I have a good smoke trail while in flight.

fredira

I have 2 Saito 56 & A 180
One in a Kadet Senior and the other in a cap 232.
My 180 is in a 3-D Obsession, so can I be in the club ?
Thanks Fredira

w8ye

My Feedback: (16)

Jim Vines,

Don't forget to feel of your compression when the throttle is open. If he closed the throttle with the trim on the transmitter and then shut the radio off, your throttle is still closed.

Safebet

My Feedback: (12)

Before I did the checking, I removed the engine from the plane. I visually checked the throttle opening as I flipped the prop. I tried in both open and closed positions and there was no difference. Little, if any compression. Seems like on occasion you could feel a little. I am going to adjust the valves, especially that exhaust (.030 gap) and then see if that solves the problem. If not it is going to Horizon to be repaired.

Horizon Hobbies is the place to send them, correct?

w8ye

My Feedback: (16)

OK,

The valve you have with the extra clearance is most likely stuck partially open?

Safebet

My Feedback: (12)

During the check with the glow plug out, I shined a flashlight down in the cylinder and rotated the prop. I could see the piston move up and down and you could see both vavles come down. Now the exhaust may not be seating, but it is moving somewhat at least. Maybe the valve guide is not gaulded.

Garthwood

w8ye................What you're saying that if the pressure tap on the muffler is facing downwards there would still be some fuel left in the muffler. My pressure tap on the muffler is facing downwards, I will rotate it to face up and see what happens. I did'nt know that this would make any difference. Why is that ?.
Thanks.

Charles.

Garthwood

Jim...................I had a similar thing happen to one of my 72s. One minute I had compression the next it was gone, prop rotated freely. Sent the engine to Horizon to have it checked out. They said I had a bad front bearing. Ended up changing both bearings (I requested to Horizon Hobby to return my bearings, which they did). They also cleaned the cylinder head, they said I had a build up. Ok. The two returned bearings were just like new. I normally put after runn after I'm finished flying for that day. I inspected the two returned bearings , I could not see any rust or damage. Attached pictures of returned two bearings on my .72. No sign of rust.
In one of the pictures I removed the front bearing covers. I do believe in putting after run oil. After this service compression was ok. Most probably it was just a build up on the cylinder head.


Charles.

Safebet

My Feedback: (12)

UPDATE: Carried to the club. Found that the exhaust valve was sticking open. Was not coming all the way to the top. Poured some mystery oil on the rocker arm and down the valve spring and stem. Pressed the rocker up up and down. It would sometimes pop up completely like it should but you could definately feel the difference between the exhaust and the intake. The intake was so smooth and the exhaust was rough. Boxed it up going to send to Horizon.

Thanks for all the help and tips.

w8ye

My Feedback: (16)

It really doesn't make too much difference whether the tap is up or down. Most people ignore the liquid that collects in the pressure line when the tap is turned down.

philfun

My Feedback: (58)

Hi,

I have a question concerning reassembling the came gear on Saito .72
Is it any mark to align with the crank ?

I am sure it's already answered in the 412 pages !

Thanks

Phil

TimC

philfun, the easiest way I've found is to run the crank pin up to top dead center. Hold it there with a finger and install the cam housing. If it is correct, you should be able to look down the intake lifter bore and see the small hole in the intake lobe centered in the bore.

w8ye

My Feedback: (16)

I stick a pushrod down the intake lifter bore of the cam box to hold the cam in the correct position.

There's an oil hole in the intake cam that aligns with the lifter position when the index mark on the cam is at 6 O-Clock

philfun

My Feedback: (58)

NEW 36cc GAS SAITO

w8ye

My Feedback: (16)

A 18 X 8 prop on a 220?

RVM

About time we've seen that engine actually mounted on a plane.

I wonder when it will be available for purchase in the US.

Captcrunch44

the guys that have been talking about that say a 20X6 biela is the one. crunch

iflyfisher

Got the Saito .91 in the Citabria working again. I had adjusted the valve clearance, fueled up with fresh Omega 15%, and the blasted engine kept dying coming off the glow. I tweaked the low speed idle, and still couldn't get it working, so I decided to change glow plugs. When I pop the head lock off my plug, I saw I had one of those stupid McCoy plugs in there. I usually only run OS Type F. I don't know why that plug was in there. I know I ran out of Type F plugs at one point last year, and must have used one of the McCoys I had sitting around. I felt like kicking myself. I swapped out the plug with a new Type F, and wallah! Problem gone. I think I had my low end a little lean as there was a slight delay in the rpm drop to idle from full power. I opened the low speed idle about a 1/4 turn, reset the high speed idle, and the idle down pause seemed to have gone, and the plane rev'd up just great from idle.

Go figger! Thanks for all your input.

Ken

overbuild

I need advice where I can find a muffler right angle adpter for my Saito 120. Horizon has the part on b/o.The part#is sai120s140.Thanks for any advise

Garthwood

ifisher......................try GREAT HOBBIES in Canada toll free # 1-800-839-3262. Tech. line 1-902-569-3262

It's probably a non stock item, but you'll never know you might be lucky.

Charles.

Garthwood

iflyfisher..................I forgot to mention also you can use a flex pipe with a pressure tap for in cowl. It's about $50.00 ? I've used one of these in my Waco YMF. Here's a picture of what it looks like.

Charles.

chasrb

Question: Can the carb from teh 90 twin or 182 be used on the 100 twin? Or even use two seprate carbs?

scratchonly

Clamp it to the firewall some way or the vibration is likely to break it.