Author Topic: Having Saito .30 break in woes-more twubble now (Read 2126 times)

wwwarbird · « **on:** May 22, 2008, 07:49:30 PM »

I've got two Brand new Saito .30's that I plan to use on my new PBY Catalina soon. I'm running them on an ARF Primary Force to just get some time them. With this first engine, the very first time out the plane/engine combo seemed near perfect with Sig 10% nitro 20% oil (1/2 castor 1/2 synthetic), a wood Master Airscrew 10-5 and 57.5 foot lines. I put about 15-20 flights up in three separate sessions with great, consistent results each time out. With no changes, the next time out I fired up and launched, and the thing would barely get out of it's own way on takeoff, using 3/4 of the circle to get up out of the nicely trimmed grass and still taking much persuasion on my part to get airborne. Once in the air, the engine flew it with little authority and would sag with any upward input at all. As each of these flights progressed the engine would act this way, and then about mid-flight end up slowing to a point where I'm flying like a carrier plane at low speed, just hanging in the air-BARELY. It ends up sounding like it's becoming heavily loaded and then finally quits, leaving almost an ounce of fuel in the tank. I've tried probably 10-15 more flights going back and forth to a 10-5, 10-4 and a 9-6 wood all with the same results. I've yet to run the second engine. What's going on???

Allan Perret · « **Reply #1 on:** May 22, 2008, 08:06:24 PM »

I had similar symptoms with a Saito 40 during break in period. In my case I had it just a tad too lean and it was overheating and bogging down. But the Saito's are tought and took the abuse with no sweat. I ran mine on the bench about a dozen times, initially staying below 4K like the manual says. I had 3 or 4 lean runs up untill I got about 20 flights on it. Not sure if thats what it took to get happy or I just finally learned how to set the needle..

Alan Hahn · « **Reply #2 on:** May 22, 2008, 09:01:09 PM »

Well try the obvious things, like maybe you need a new plug. During breakin, you might be getting some Aluminum "dust" into the plug. Does the element look shiny or frosty? (should be shiny)

Check the valve timing. It might have worn in a bit,and now they aren't opening as much as before. Also while you are looking, make sure that area is getting some blow-by oil into it. Also are you getting some oil out the breather tube?

That about does it unless the tank or fuel tubing has issues.

Bob Reeves · « **Reply #3 on:** May 23, 2008, 04:43:26 AM »

So far you have received a couple good tips..

I would get away from using any castor, Saito reccomends all synthetic and my experience says they know what they are saying. If you can find it use PowerMaster YS-20-20.. 20% nitro 20% all synthetic. This will keep the valves clean and gunk out of the needle.

Next I would see if I couldn't find a 9-7 prop. I would never use anything below a true 6 pitch on any Saito. I'm running 11-7's on my 40's and when I first set up my 30 I'm going to see if it won't swing a 10-7 guessing I'll end up with something like a 9.5-7 cut from a 10-7.

Are you using the RC carb? With the above fuel and prop you will not be able to run it wide open unless you like 4 second lap times. Set the carb so the engine is turning a 7 pitch prop at about 8100. The needle should be set just to the rich side of peak. Fly it and fine tune the carb (and needle) setting for around 5 second lap times.

I'm running 2 40's (soon to be 3) and two 56's using this aproch and all are as consistant as anything I've seen fly including piped ships.

Don Curry AMA 267060 · « **Reply #4 on:** May 23, 2008, 10:48:59 AM »

I have not used any 4 cycle's for c/l yet but in r/c have used Saito .40's .56's .80 and 1.8 and have had excellent results with the YS 20/20 fuel Os f plug and setting the carb about four clicks rich of the peak rpm.

wwwarbird · « **Reply #5 on:** May 26, 2008, 01:41:54 PM »

I went out earlier today and took off and flushed the tank ,fuel lines, filter, and blew out the needle valve etc. Then I put everything back together and test ran it on the stooge, still with the same results. I then took out the original Saito plug and put in an O.S. Max 4F (O.S. plug on a suggestion) and test ran again. The engine immediately sounded smoother and ran better. It seemed real happy dialed in at 8500-8600 rpm with the Master Airscrew wood 10-5 back on. I then put up two flights and all went well. It's pretty windy today to do much more, but it appears to be back where it was, which is good. I knew I should have tried a new plug earlier, but I just had a hard time convincing myself that the original Saito one could be bad already.

Alan Hahn · « **Reply #6 on:** May 26, 2008, 02:22:03 PM »

I know it may sound a bit strange, but I got the advice to change plugs after breakin from Larry Foster's instruction for breaking in his Fox35 (L&J)--a pretty far jump in technology from a modern 4 stroke engine.
When you are breaking in, things are actually wearing in, making small amounts of metallic dust. This crud can contaminate the glow plug element. When that happens, it doesn't work as well. In order to compensate, you typically turn in the needle. This leans the mixture, and at least on the ground the engine sounds better. Once in the air, the engine finally begins to warm up, eventually beginning to overheat. That's when it starts to sound gutless.
One thing I do if the engine comes in with a pretty good plug (like an expensive 4 stroke plug), I'll switch out to a cheaper plug to do the breakin. Then I don't feel quite as bad when I throw it out afterwards (I am pretty cheap when it comes to glowplugs!).
But also, check the valve clearance, it still may need to be adjusted.

Steve Helmick · « **Reply #7 on:** May 26, 2008, 06:26:07 PM »

The Saito plug is said to be an OS "F" in a different bubble pack, and I think they're a little cheaper from Central Hobbies in Montana. I've used the Thunderbolt 4 cycle plug, but in a Double Star .60bb. Might do for bench running, at least.

The picture below, I just took, shows "YS" and "4" on all the flats that I can read without opening the packet. On the back, a pricetag from Central Hobby, $10.95 reg, "our price" $5.39. I'd expect the price to be a buckatwo higher, as these were bought before the dollar went Southward.

I just hafta ask...did you break-in the Saito per the instructions, throttled back and all that? It might just be important....

Steve

wwwarbird · « **Reply #8 on:** June 10, 2008, 05:47:24 PM »

Well, since my last post, I've been back to the field three times and after getting only two good runs with a new plug it's is back to the same problems all over again. Yesterday, I checked the valves (which were just a tiny bit loose) and I put it on the test stand then experimented with about fifteen different props. Everything you can think of in 9" and 10" two and/or three blade. The engine acted the same with every prop I tried. It runs smoothly, but just will not accept adequate leaning of the needle at full throttle. By the book, it should swing a 10-5 at close to 12,000 max RPM. It won't begin to take anything over 9500 without sagging with any prop I've tried. The engine was broken in per the Saito manual specs. The only real difference is that I am currently running it on Sig Champion 10% nitro with 50/50 castor/synthetic. I've tried Wildcat 15% nitro with 18% synthetic (50/50 if I remember correctly). I know it's "recommended" to use all synthetic, but I have witnessed MANY four strokes, Saito and O.S. run just great on this fuel. In fact, this one ran flawlessly it's first 10-15 flights on the Sig fuel I've mentioned.

Alan Hahn · « **Reply #9 on:** June 10, 2008, 06:17:59 PM »

I think I ran a 10-6 on mine, but I don't think I would run it at that high an rpm. Sorry not to be more specific, but 12krpm isn't a super idea (IMHO) on a 4 stroke. I would shoot for 10k on the ground at the highest.

Scott Hartford · « **Reply #10 on:** June 10, 2008, 09:21:22 PM »

I have a few Saito 30s and OS 26s and 30s. On the larger engines, conventional wisdom says don't rev much past 10k. These smaller engines are also available in car versions that rev to 19k, so revs are not ever going to be a problem. A 10-5 APC is my go-to prop, or a 10-4 if you need more speed.(It sounds backwards but try it!) 20% nitro is what they like and 20% synthetic oil works best, mostly because that's what the needle is set up for. I run the RC carb wide open, but control speed with the prop. The mixture should never be used to control engine speed on a 4-stroke. The needle should be set 300 RPM below peaked, with about 10 seconds to stabilize when making any adjustment. The OS F plug simply works (in all Saitos). Keep in mind that these engines need at least a gallon of fuel through them before they get sweet. The power will increase noticably after a good break in and fuel consumption will go way down.

Bob Reeves · « **Reply #11 on:** June 11, 2008, 05:07:41 AM »

Have to say again..

When I was running my 30 with a 10-4 prop and the carb wired open on 10-22 it was a piece of crap.

Stick a 9-7 on the darn thing, change to 20% nitro 20% all synthetic, close the carb down about 1/2 way for a launch RPM of around 8200, use a plastic clunk tank and set the needle just on the rich side of peaked. This works and you will never see what that little engine is actually capable of till you try it.

wwwarbird · « **Reply #12 on:** June 11, 2008, 08:55:19 AM »

Thank you Bob,

The only reason I haven't tried all syn fuel yet is that I don't currently have any, and it's not easy to get ahold of around here. But, I have run 9x6's and 7's on it at 8100 to 8500 RPM and the plane can't get out of it's own way, literally. Same results with every prop I've tried. I will try the other fuel as soon as I can obtain some, but the fact remains that I have seen .40's and larger run perfectly with the fuels and combos I've mentioned. And again, this particular one ran BEAUTIFULLY and with good power for it's first dozen or so flights, and then the problem started.

Bob Reeves · « **Reply #13 on:** June 11, 2008, 11:54:56 AM »

OK starting to sound like something else is going on but not sure what.. Even with my worst setup and fuel it would fly the airplane well enough to get through the pattern. From what it sounds like you are saying your problems are more than just quality of run.

Can't look back or remember, did you say both your 30's are having the same problems ? How does the compression feel compaired to when you first turned them over? Did the rockers look to be working properly when you adjusted the valves.. Looking for the possibility of a bent push rod or castor gummed up ring..

Edit: Now I see you haven't ran the second engine yet.. Break it in per the instructions, try it with the same setup you are running and see what it does..

L0U CRANE · « **Reply #14 on:** June 12, 2008, 04:57:49 PM »

wwwb,

I haven't used or handled any SAITO engine, but it sounds like the mfr recommends all synthetic oil for a reason. Castor can and does gum and varnish. Synthetics clean the metal. For many engines, a 50:50 blend works. If SAITO stands behind their products when used with all-synth, there may be fits, or passages in the engine that need to be cleaner than castor can leave them - and castor can gum in a few weeks without use.

Did you use an after-run oil, if SAITO recommends that for periods when the engine will not be used for several days?

SAITO engines have an excellent reputation. I'm curious - do the instructions mention how much running-in time (including flying) they should take before they're fully broken-in? Some engines give a number runs or minutes suggested before flying, then another length of time for taking it easy on the engine in-flight before going for ultimate performance...

I've also heard that it is hard to set some 4-cycles by ear. Do you have a tach? To be sure enough oil is going through the engine, you may do well to lock it at full-throttle (unless you have a built-as CL-intake version) and lean the needle until it stops gaining RPM. Richen it back to where you see RPM just start to drop. I've seen it; over-lean doesn't sound different from the richer setting where RPMs just start to drop off. When we are near enough to the engines to make the adjustments, there are many harmonnics, overtones and other noises that can confuse us, but which don't carry to 20' or more away from the engine. That's why a tach may be more certain for setting the needle.

Robert Zambelli · « **Reply #15 on:** June 14, 2008, 09:45:36 AM »

I have had considerable experience with the SAITO 30 and I’d like to add to this thread.
I have six of these little gems and only one of them had to be sent back for work. After some valve adjustment issues, I sent it back to Horizon Hobbies (one of the BEST model aviation organizations I’ve ever dealt with) and they replaced it with a new engine. It has been running flawlessly in my Argus for the past four years. The 30 is my all time favorite engine and in the Argus my all-time favorite airplane/engine combination.
I have a 30 in my Little Cherokee that is perfect after nine years and hundreds of flights. The valves were adjusted ONCE and it still has the original plug. I have never had to remove the engine.

Here is what I do and use:
First, in any 4S engine, I always check the valve lash. I then pour oil over the valve train and inject some into the case, insuring that every moving part is well covered.
I run the engine in for a minimum of one hour, using the fuel described below.
I then re-check the valve lash and it’s usually ready to fly.
I have found that if the engine runs hot, inconsistently or uses excessive fuel (more than two ounces for the pattern for the 30), it needs more run-in time.
Fuel - I used Powermaster 10/22, 50-50 castor-synthetic for many years with excellent results. I have recently switched to Brodak 10/23, also a castor synthetic blend. This has become my fuel of choice for all my engines, including my Fox 35s. Running these fuels, I have never had to do any valve work.
Plugs: I use whatever comes with the SAITO. I have NEVER had a failure. Also, I have tried every 4S plug on the market and I’ve never found any difference.
Props: After trying many, the one that works best on the Argus is an APC 9.5-6. the Little Cherokee likes the Master Airscrew 9.5-6 plastic prop. I NEVER go below a 6 pitch.
Tanks: I’ve tried them all. What works best for me is a simple metal wedge with a vent placed in the forward upper inboard corner. I do not like uniflow or clunk tanks. The only exception is the Argus - for some reason, the simple setup would not work so I had to go to a Z-Tech Eagle Hopper.
Muffler pressure - ALWAYS!!!
Induction: I always use the carb on the 30. The Little Cherokee has a throttle and the Argus carb is wired wide open. Never a problem.
Intake venting - an absolute requirement. The 4S engines need fresh cool air for ultimate consistent runs.
I install a tube that delivers air directly to the carb from the top of the fuselage.
Starting: By hand in a normal manner.

Although I’m not a fan of engine mods, I do a minor one to all my 4S engine. Instinct told me that the muffler outlets were too small so, as a matter of course, I always open them up, increasing the cross sectional area by around 50% . When comparing one to a stock muffler, I found this to be very beneficial to all my 4S, especially the SAITO 30. In fact, I just opened up the muffler of a new SAITO 62CL and the improvement was quite dramatic.

As most of you know, I’ve had a lot of flight time with 4S engines and while not for everyone, they are definitely my engines of choice. I’ve flown every size from 20 to 91 and have settled into the smaller displacements. I plan to build a new plane around the 30 and my triple carries three 26s.

I hope this info helps,

Bob Z.

wwwarbird · « **Reply #16 on:** June 15, 2008, 03:34:00 PM »

Thank you VERY much Bob, I was hoping that you'd chime in. The "basic setup" with the wedge tank and all that you're describing is exactly what I know will work, and am going after. I've seen the combo work well in all cases I've witnessed, just no prior experience here with the .30 size engine. I also feel that this engine is capable of running just fine on 50/50 fuel. You've mentioned using a Master Airscrew 9.5x6, is this a cut down 10, or do they make one in that size that I haven't seen? I also agree with the idea that the Saito's take quite awhile to get fully broken in from what I've seen and heard. Everything you've described is right in line with my own thoughts. However, I'm thinking that I should send this one into Horizon and have it checked out though.
I'd really like to see a pic of your muffler modification though-any chance you can post one?

Thanks again!

gary tultz · « **Reply #17 on:** June 15, 2008, 09:45:47 PM »

My 1.98 I'm not a fan of 4 strokes. I like 2 strokes and electrics. I have seen 4 strokes run in all forms of quality, tune and power from sick, gutless and weak to super consistent with thundering power. I've seen and judged them at local flying sites, the Nats, the Worlds and Brodaks. If I was going to use one for competition at the highest levels or just having a ball with a Bi Slob or Ringmaster, (Bi Slob? anyone tried that?) I'd follow Bob Z's advice to the letter.I've watched him run 4 strokes over ten years now and I think he must have invented them. Bob is a top level Aerospace Engineer and Gadgiteer. Model engines are a Passion .The two Saito 30s he flies run like Swiss watches. Don't ask how good he is with Sparkers. Hey Bob, I need a new spark plug for my Fireball. I broke the Champion at Brodaks. Got a recommendation?

Robert Zambelli · « **Reply #18 on:** June 16, 2008, 04:11:27 AM »

Gary - I've got plenty of plugs. I'll send you one.

Can't remember - long or short reach?

Bob Z.

Robert Zambelli · « **Reply #19 on:** June 16, 2008, 04:24:39 AM »

Hi, Warbird. I will gladly post some pictures for you.

As soon as I get back to SC, I'll take a few shot and post them, along with dimensions. OK?

Bob Z.

wwwarbird · « **Reply #20 on:** June 16, 2008, 12:26:21 PM »

Thanks Bob!

Author Topic: Having Saito .30 break in woes-more twubble now (Read 2126 times)

Alan Hahn

Alan Hahn

Alan Hahn