JettPilot

My Feedback: (6)

I am still trying to get my Saito 150 running correctly. It is using a 16x8 APC prop and a Perry 30 pump with the T configuration and 4 inch lines from the crank vent, one open to atmosphere, and other to perry pump, muffler pressure blocked off and tand vented to atmosphere. Seems to feed fuel perfectly under pressure. It starts pretty easily also... Here is the issue.

At idle of around 3000 rpm, low speed screw is very sensitive, around 1/8 turn either way almost kills it.

With the low end mixture adjusted for max RPM at idle, it is so rich at mid throttle that it suptters, smokes, and quits [sm=drowning.gif] when I try to advance the throttle or even just run at half power.

If I lean out the low end mixture for maxiumum RPM and smoothest running at midrange, its great, but it will die immidately from starvation anywhere near idle.

Full throttle RPM was 8,900 and the HS mixture takes about half a turn on the HS needle to go from 200 RPM rich to max rpm and then lean 100 RPM. Seems to run very well and stable at full throttle with lots of power .

I know each needle affects the other, but after hours of running, adjusting and readjusting, the end result is what I describe above [sm=crying.gif]

Any ideas on what might be wrong here ?

JettPilot

HOOTER

Hello again all!!! Club Saito # 223!!!

I have added a new engine and plane to my fleet. Well....ugh the plane is parts and peices of three crashed (not all mine!!) 60 size UCD's!!

It is a UCD Biplane with a Saito 125, and believe it or not it fly's great!!

solafein

It sounds like your fuel pressure is a little high at idle. I could be wrong here. How far off closed is the LS needle? Just for giggles take an extra piece of fuel tubing, shorter than your current vent, and attach it to your "T" fitting and re-run.

William Robison

My Feedback: (3)

Jett:

Classic symptom of the fuel pressure being too high. Probably will take at least a full turn OUT on the pressure screw, the one in the end of the pump between the in and out nipples, but don't go more than 1/2 turn at a time just to be safe.

Bet your HS needle is just about shut at peak, the 150 and 180 seem best with the fuel pressure giving you 4-5 tirns open at peak.

Bill.

William Robison

My Feedback: (3)

Sol:

Agreement once again. I just find it easiest to use the HS as an indication of pressure, I'm sure you could get there using the LS as an indicator also.

Looking at the time stamp I posted eight seconds before you did, yet your post shows first. What's up with that?

Haw.

Bill.

solafein

I didn't have to go through a moderator first.
Just kidding
Haw.

Seriously, a High Speed Internet connection is faster here in Sunny Southern California, all that pure Pacific air and unrelenting sunshine.
Haw.

I take it that you recommend the VP-30 over the VP-20 because the 30 is actually driven and the 20 relies upon parasitic inertia.

I will be putting a fuel pump on a FA100 in a P-51 kit I am building so this is interesting at this point.

skillet92

Mr Robison,
I just read your report on the HS and LS screws and they are going to help me a lot with my 125. I have over a half a gallon through it and i am having some trouble getting it right. I do have 2 ?'s How much cooling or air flow do i need. It is mounted on a FW-190 and the cover completely incloses the engine and 2 how do you know if it is to lean?

William Robison

My Feedback: (3)

skillet92:

The most definite test for lean mixture in a particular installation is to peak the engine rpm with the HS needle, open it to get your 300-400 rpm rich drop, then with the tank close to empty point the nose straight up and listen to the engine. If the rpm falls off at all, even after 30-40 seconds, the setting is too lean. Ideally the rpm will rise just a little bit with the nose up and the fuel almost gone.

This works because the fuel has to be drawn the furthest against gravity with the nose up and a nearly empty tank. You may find the engine is running richer than you think it should with a full tank on take off, but you wont go lean in flight, and the Saito engines run great even when they are a little rich. Too lean is another matter, too lean is to be avoided at all costs. Or the cost will go up.

If your engine is using an accessory muffler that also is fully within the cowl except for the exhaust pipe you are most likely running hot. Not enough air outlet area. If instead tou have the stock muffler going through the cowl, with at least ½” clearance all around it, you might be OK. Rule of thumb is the outlet area should be 2½ times the inlet area. If the opening in the front of the cowling is, say four square inches you need ten square inches of outlet area. Sometimes you can get away with less, but you have to be careful checking to be sure it’s OK.

How do I know if your engine is overheating? Unless you bring the plane to western Florida and run it for me, I can’t tell. But you can. The common symptom of getting too hot is the rpm falling off in flight, the engine “Sags” and you have to keep opening the throttle to maintain rpm. Or at full throttle you lose power. You can also have a frying or crackling sound from the exhaust.

Running too lean will lead to overheating as well as a lack of cooling air. If you can fly your FW-190 with the engine cowl off, do so, and confirm the needle settings. Then, without changing the needles, fly it with the cowling on. If the engine sags with the cowling and did not when it was running in the open you need more air flow.

Really not complicated in any of these checks, but many people don’t bother. And they have running problems.

Sorry to run on so long, but I didn’t see much way to shorten it and give a good explanation.

Bill.

PS: You’re in Club Saito as number 311. Glad to have you. wr.

skillet92

Thank you!!
That is just what mine is doing. With the cowl on i was losing rpm at full throttle and it would not pick up as well. This is the first 4c that i have owned and it seems to be harder to set up than all the 2c that i have played with, but tonight i am going to try your tuning setup and get it right. I do have a tach so that does make it easier, but usually i can here the change in tone when i move the hs. I did not think that it was that critical to get the ls in tune with the hs. And so far i have been aiming for an idle about 1500 rpm. That is what an article in some mag that i read said was the idle. If i do not need to go that low it will be great!!

William Robison

My Feedback: (3)

Skillet:

Just remember please, you can ONLY adjust a Saito HS needle at full throttle. Trying it at anything less than full throttle will NOT give an indication of any misadjustment.

Bill.

XTRA230

My Feedback: (10)

Hi All
Looking at gettingA 220 Deal is nearly done,Does not come with A Muffler Which ones fit Has ant body 1 they wish to sell or where is best place to BUY This is my first post with you guys
Rob (Australia)

XTRA230

My Feedback: (10)

Hi All
Looking at gettingA 220 Deal is nearly done,Does not come with A Muffler Which ones fit Has ant body 1 they wish to sell or where is best place to BUY This is my first post with you guys
Rob (Australia)

William Robison

My Feedback: (3)

Rob:

The Saito FA-220 is sold WITH muffler. Unless you are getting a used one I would think some one is trying you on. Go [link=http://www.horizonhobby.com/Products/Default.aspx?ProdID=SAIE220A]here[/link] to see it from Horizon Hobby.
I can not imagine the engine being sold otherwise, even in Oz.

Bill.

skillet92

Mr Robison,
Thanks for the tips they worked great. I now have the top and bottom end set for right now. I have not yet put the cowl back on, but before I do I plan on cutting some more holes for air flow. I ran it for almost 22 minutes and it did not miss a beat. I can not wait to get this best in the air.

XTRA230

My Feedback: (10)

Hi Bill
I realize this New comes with Muffler But The 1 I am getting is slightly used,Muffler lost!! And the price is low.Thanks for the info.Which muffler (factory)Fits Are they the same 120 150 180!!
Thanks Again
Rob

William Robison

My Feedback: (3)

Rob:

Sorry, nothing else fits. The FA-220 has a larger exhaust port thread than any other Saito, and I doubt any other glow engine has one as large either. You might check with Mac’s and Performance Specialties, but they both are generally more expensive than stock.

Here are the Saito part numbers, and USD prices.

Exhaust pipe with lock nuts SAI220A75, $11.39
Muffler SAI220A74 $49.59

Hope this helps.

Bill.

wkunkel

My Feedback: (8)

Hey guys
Success ! I finally got this 1.50 really right. With your help, Bill and Ron, I'm finally going to maiden my Dave Patrick Ultimate on fathers day. Some pretty dum things were keeping me grounded. The engine looked pristine when I bought it from an estate sale, but it was a lack of maintainance nightmare. Some small parts were left out at some point in it's life such as the aluminum washer under the intake manifold, and the shim washers for the rocker arms. I found what was probably the worst kulprit when I went in to adjust the valves. The bolt that mounts the whole rocker assembly was loose by about two full turns. After tightening that and doing a close tolerance valve adjustment, ( thanks Bill ), and going through the check list, (thanks Ron ), put it on the test stand and fired it up. A few minor needle adjustments later, and I've got a sweet running, smooth idling, instant transitioning, Saito 1.50. And, so far, I have not added a regulator.
I'll know on Sunday if I might like to add that. I doubt it though. Thanks again guys . I can't wait till tomorrow !

William Robison

My Feedback: (3)

Wally:

I wont wish you good luck with the engine as you really make your own luck, and it sounds like you have made yourself a batch of the good kind. Glad you got it sorted out.

I will wish you good luck in flying the airplane though. Haw.

Let us know how it goes.

Bill.

XTRA230

My Feedback: (10)

Hi Bill
Thanks for that,Well still makes it cheap as they are Around A$890 Down here With the post and new muffler It will be Around A$430 Cant wait now as I Plan to put it in My Great planes P6e Hawk Should be really Nice Thank you again Bill
Rob

waring_abbott

Hope that someone in Club Saito can help with this. I have many Saitos, truly magnificent engines, all works of art. My history is I flew a lot in the late '90s then laid off from 2000 to now (lived near the WTC and moved after 9/11, was not able to set up a workshop and get back into flying until just recently). Main question is: trying to install the Saito 4 stroke 180 into a Hanger 9 120 Lite (also have another 180 for the older version of this ARF). Can't seem to get the throttle linkage right. Hanger 9's suggestion of a using an easy connector to the throttle servo arm seems to bind up too much for comfort, no matter how I try to finagle it into place. I've tried all sorts of bends in the wire (minus the easy connector) and just can't get it to operate freely. Has anyone else dealt with this already? It is kind of weird dealing with a throttle that moves in two directions simultaneously -- back/forward and laterally. Without that lateral movement this would be much easier. By the way, hole for throttle linkage here is exactly the way Hanger 9 wants it: half way down right side of fuselage, directly out fo the firewall. Any and all advice very much appreciated!
thanks,
Waring Abbott/NY

William Robison

My Feedback: (3)

WA:

Using a moderately stiff wire extend it forward of the engine, then loop it back to attach to the throttle lever. The added length will allow sufficient flexibility to accomodate the dual movement.

Alternately, look at Du-Bro's #665 linkage set.

Bill.

skillet92

One more question,
I have a saito 125 and am thinking of running the exhaust a little different. I have the pipe and the muffler mounted normally and right now have a rubber exhaust deflector mounted on the end of the muffler. When it comes out the cowl it leaves oil everywhere. I was wondering if i leave the muffler where it is at can I add a piece of tubing and get the exhaust behind the main wing or will that be to far and mess with the engines tuning as far as back pressure? I have a piece of tubing that is the same size as the opening of the muffler. Any advise would be helpful!!

William Robison

My Feedback: (3)

Skillet:

If the tubing will stand the heat of the exhaust it should be fine. Saito engines don't seem to be particular about the length of the exhaust.

A lot of your mess could be coming out of the carb also. Install an intake stack and a Bru-Line fine mesh air filter. Your flight time will go up as well.

Bill.

Dave :^)

Bill,
would I get much benefit from fitting a velocity stack to my '65 or do they suit the bigger engines more?
Dave :^)
#305

William Robison

My Feedback: (3)

Dave:

Fuel savings will depend on how old your FA-65 is, and whether or not the original cam is still in it. The early Saitos, and the 65 is the oldest single still in production, had very mild valve timing. Along with this, they had excellent fuel economy and almost no fuel was blown back out of the carb. They were also heavy and didn’t have a lot of power.

Check your firewall, or if cowled the inside of the cowling. If it always gets sloppy with oil, or you can actually see fuel spitting back at low to mid thro0ttle settings, you will get an increase in economy with the stack and filter.

I think the stack and filter are worthwhile even without a fuel savings – they keep the trash out and you have lower maintenance costs.

Bill.