Hobbsy

My Feedback: (102)

Bob, you seriously risk a burned valve going even to .002, my 1.25 loses about 200 rpm using .002.

Mikecam

Hobbsy I have mine set at .002 after reading that width on here. What should I have it set too. Thanks

WMB

My Feedback: (1)

FWIW, back in the day when I was helping motor bike racers with their engine. We use to set up valve clearance on the loose side of spec thinking that would allow better valve seal. I look back now and wonder if it really made a difference.
the guys I helped usually placed real high or crashed. A couple of those guys were LOCO.

Hobbsy

My Feedback: (102)

.002 is the setting for Enya engines and .004 for Saitos.

Big-Mo

My Feedback: (5)

Hi all I got a little problem with my Saito. it is a 5 year old saito 150 aac, runs good only had about 1 gallon of fuel through it . the issue I'm having with it is a surging fairly bad at 3/4 to wot. Ive adjusted everything i can think of and read. I am using 15% wildcat 18%plus fuel with a apc 16-10 prop , the plane is a four star 120 kit. thought it was running lean so i installed a Perry pump(shaker style) and it didn't help the surging .

I'm all ears looking for any info or input to a solution.

Thanks
Big-Mo

Ken6PPC

Hobbsy, I remember LOTS of posts here that recommended .002" or even .0015" valve clearance for Saitos. The late Bill Robinson was one of those recommending .0015". The point being, valve clearances on these engines always get larger as the engine heats up.

Have you experienced burnt valves set at .002"?

mike early

How does one install a new spray bar?
If I pull it in with the lock nut, it rotates. Does one press it in somehow?

Rudolph Hart

EZ are you buying an arf decathlon? @ 65"..if so you might save yuorself some money by fitting the 82 which i have just fitted,will let you know how it goes after flying the 62 which is adequate.

AircamperAce

My Feedback: (11)

Hey guys, I picked up a Saito .72 in a swap. It looks nice and shiny but I found a few issues so far; first, the crank is very stiff/rough, plan is to dump some MMO in it and give it time to soak. I may get to learn how to change out bearings if it doesn't smooth out. Next, the mount holes look over-sized, I may try to make some sort of bushing to slide in there, not sure, any ideas? And last, what is the purpose of the ring on the intake tube? Mine looks damaged, does it serve any purpose?

Ryan

sodbuster 1

any feedback using the Saito flex mufflers?

thinking of using one if it's availabe with a 90 degree bend for the 1.15 in the Spit I'm building to keep a nice uncut cowl

not having a lot of luck figuring out a part number fom the Horizon site though............

So far I've only found one that's labelled 12mm but it has no nipple for tank pressure

mike early

The flex work great, sometimes. The first one broke after 2 flights. Good customer service will help if this happens.
SAI182TD1112 is what you seek.

mike early

I have to buy another high-dollar intake manifold! argh!

Hobbsy

My Feedback: (102)

The 16x10 is the problem, rpm too low making carb impossible to adjust.

RC Specialties

sodbuster 1,

I have an option for the spit I have been working on. I am using it on my spit. Drop me an email and I will send a pic.

Jim
[email protected]

Kmot

My Feedback: (24)

I think that is just a surface for an o-ring to butt up against. Looking at a picture of a replacement intake pipe for the 72 it seems that way:

mike early

how can that thing cost 25 dollars?

Kmot

My Feedback: (24)

This is quoted from Bill Robisons "Saito Notes"

Now we come to the point of contention. I set all my Saito engines at 0.0005" clearance. Right. That’s 1/4 of the minimum given in "The Book." In point of fact, even if you have to force the 0.002" feeler strip between the rocker and the valve stem, so long as you can feel some wiggle in the rocker the valve is not too tight. When set at 0.0005" cold, the running, hot clearance is close to the 0.002" specified. The clearance always opens as the engine warms up.

There are many advantages to using the minimum clearance, including more power from the greater open duration, less valve gear wear from lessened hammering, and so forth. But it does take a dial gauge set to do it with precision, or a very good feel with the wrenches.

Another way to check for a tight valve is just flipping the engine with the throttle open. If you have good compression the valves aren't too tight. Might be too loose, but not too tight.

The people I've convinced to use the half thousandth clearance wont go back to two thou, but it's hard to make the converts.

mike early

Isn't it possible the pushrods get hot and expand: Decreasing the clearance?
(That's how it works in my old car with solid lifters. The exhaust requires more clearance cold to compensate.)

Or maybe the actual Saito cylinder expands at a high rate than the pushrods and it gets taller? Hard to imagine...

Rudolph Hart

I can feel a 500 page buster coming on with this subject.

Mike early do you have any play in your throttle linkage?

EZchopper

Hi Old Fart,

It's the Seagull Decathlon. A club mate has one with an SC70FS. It flys really well, more than what I need
I know of and seen the same model with a Saito 82 and that really really flys well
The price of the Saito 82 in UK is £160+ and is a bit of an over kill for my intentions for the Decathlon
I do love my Saitos, a 82 and 125 in my other planes

Was checking out the price for the SC70FS and found the Saito 62 was only slightly more at £120
The kit says a 52 4 stroke but I know thats not really enough for it
The Saito 62 was also cheaper than the 56

Be nice to know how your 62 goes

AJsToyz

Mike,

I was thinking the same thing too. The only thing I can think of is the cylinder expands more than the push rods giving it more valve clearance. On the old car the block is cast iron,and on theSaito the cylinder is aluminum.

Andy

sodbuster 1

2 members of our club have/had this version of the Decathlon.

One had it powered with the equivalent of a .40 2 stroke in electric. Not enough power and tended to tip stall very badly. So much so that on his last takeoff it tip stalled,winged over and was unrecoverable.End of plane.
The other member has a Saito .62 in it and it flys perfectly scale. Will do anything the full size will and sounds sweet. Gives the plane a very scale feel on low flybys at half throttle.Plenty of power for whoopsie recoveries.
While the .82 would definitely give it tons of power (and not very scale at full throttle), you'd end up having a bit of extra weight to counter balance

Mikecam

I set mine to .0015 after reading this and so I'm waiting to see some reply's.

sodbuster 1

Mike,
How did you have the flex connected?
Directly or via a 90 degree elbow?
What type was the flex pipe? One with the end cap itself threading to the head or an elbow? or one of the ones that already had an elbow integral to it?

Also, where did it break?

w8ye

My Feedback: (16)

Bill Robison's .0005" valve clearance ideals were not that successful in real practice.

I remember discussions with Hobbsy back then. Bill R. set up one of Hobbsy's engines according to his (Robison's) minimum valve clearance plan. When Hobbsy tried to run it in the colder climate in Virginia, it would hardly run. Hobbsy had to open the valves up a little to get it to run.

Jim