loughbd

I run a 14x8 rev up on an old OS FS90 and get 8900 rpm. 14x6 is way too small for a 100.

Ernie Misner

khodges, I am real curious about a "straight pipe with a pressure fitting". It worked well on the 80 it seemed, but is there enough pressure coming from an open pipe? I thought a pump was needed with a straight pipe....?

Thanks,

Ernie

loughbd

The exhaust pipe has a small restriction in it. Same pipe on the 40, 45, 80T and 90T

khodges

My Feedback: (1)

The advice is great, fellas, and I will use it all. As I sat at work today, I thought about how the engine ran, and came up with three reasons, which are probably working together. One, the prop is too small, and two, it is leaning out on top, and three, not enough time on the engine yet. As I said, the low and midrange have improved on each run, so part of it is just getting more time on the engine. The 15 inch prop will work okay, I still have an inch and a half ground clearance with the tail level, as for a take-off run, I think I'm even going to go up on pitch as well, and try a 15-8, the extra speed will be fine with me. I mainly want the improved vertical performance. This plane should fairly haul ass, it will go about 72 (clocked on radar) with the .80 at full bore.

Ernie--I was sort of concerned at first about lack of pressure with the straight pipe, but many of the twins run straight pipes without problems, and I had no problems at all with the .80. I drilled my pipe where the elbow screws onto the flex pipe and put the nipple there, it also prevents the pipe from coming loose. The tap is pretty close to the exhaust port (about 1/1/4 inch); I figure the "corrugations" of the flex pipe create enough turbulence in the pipe to make a fair amount of pressure by impeding exhaust flow. I can hold the plane vertically while running and get no hint of starvation. The sound of the .80 was really great, it sounded like a radial, and the 100 is awesome, but surprisingly not all that loud.

I left the low end needle at the factory setting for the first tank, and the high end was at 3 turns for the fist few minutes, but would hardly run that rich, so I set it back to 2-1/4 and it's fine. It leans out at about 1-1/2 right now, so I'm plenty rich and will continue to run it there for a couple more tanks. This is my 6th Saito, I've broken them all in this way, and they run very reliably and trouble-free. I try to prop all my engines to keep them just below 10,000 at WOT and this being the biggest one yet for me, the power is surprising. I was also surprised to see in the prop chart in the Saito brochure that they recommend a larger prop for the .91 than for the 1.00. I also have a .91, and I'm using a 16-5 on it; I should have figured right off that the 14-6 wasn't enough for the 1.00. Thanks again, guys. I'll let you know how she flies when I get the engine smoothed out

rlmcnii

My Feedback: (3)

KH,
Apparently you have a fair amount of Saito experience; at least, more than I. However, I think it would be very surprising if a 1.00 would run properly with the HS needle 1-1/2 to 2-1/4 turns out. The operating manual calls for 5 turns out for initial running.
In my limited Saito experience (3 engines, a .50, .82, and.91 run in and tuned), problems with wide-open-throttle running come from a too -lean HS needle valve. Fortunately, none of these three engines had any other problems that had to be diagnosed and corrected to get them to run well.
It is interesting to note that the newer manuals (downloadable from Horizon) call for engines smaller than the 1.00 to start out at 2-1/2 turns out. Neither my .91 or .82 would run properly with that HS needle setting. I believe the older manulas called for 4 turns out for the engines smaller than 1.00. Anyone out there please feel free to correct me on this point. Both my .91 and .82 would run, when new, with the HS needle at 4 turns out.
The symptoms of very rich running at low and mid speeds are corrected with the LS needle. It seems to work best to adjust the HS needle at wide-open throttle only.
These are just the observations of a relative neophyte. Good luck with your 1.00.

Kugel

Great thread!

I have a Saito 100 and a 180. I admit I'm kinda proud of em.

I humbly submit my application for membership to Club Saito.

This past weekend I was at the Toledo Weak Signals show.

There was a beautiful custom painted Saito, I thought you all might like to see it.

gjeffers

wow, thanks for the pics Kugel, real nice eyecandy[8D]

TheShirt

My Feedback: (2)

Help---- I have a Saito 80 that is driving me nuts. It acts like it's overheating, but is real rich and the cowling is removed. It will run for a while and then violently quit. Also, you get max RPM (9300 with 13x6 apc) at about 80 % throttle. If you open it any more, the RPM decrease and it loads up and then BANG - it quits.
Again, I have replumbed the tank, sealed the intake with RTV, triple checked the timing and the valve adjustment, blown out the carb and readjusted the needles a million times.
ANY IDEAS??????

William Robison

My Feedback: (3)

Kugel:

Welcome sir. You have been assigned number 263.

A lot of us paint our engines, I limit myself to the cylinders, and they are always black. Kmot though, has posted pictures of several he has done in contrasting colors.

Bill.

William Robison

My Feedback: (3)

Shirt:

Classic symptom of the HS being too lean. No, don't scoff, just turn the HS needle out five full turns and restart the engine. Don't bother the LS for the moment. Open the throttle to full. Unless you have a feed problem the engine should accept full throttle and continue running. VERY SLOWLY lean the HS until you get to peak rpm, and remember that you will always be about five seconds ahead of the engine - meaning the engine will run about five seconds before you get any response from a needle change. That's why you have to go slowly in the adjustment, this lag is the cause for many people getting a four stroke engine too lean.

Bill.


PS: You're in Club Saito as number 264. Welcome. wr.

TheShirt

My Feedback: (2)

Ok, we'll try it. Tried everything else...
Thanks

rlmcnii

My Feedback: (3)

TheShirt,
I agree with WR. When I was breaking-in my .91 it acted as you describe the operation of your .80. My tendency was to clean up the mid-range running with the HS needle. VERY LARGE ERROR. Do as WR advises. You will probably find that you will not close the HS needle very much. When it is set, adjust the low and mid-ranges with the LS needle. If the LS is still close to the new setting it will probably be very rich. You will probably be able to lean it out quite a bit.
Lean the LS to the leanest setting that will still give you a transition to more open throttle setiings without the engine quitting. As it runs in you will be able to continue to gradually lean the LS.
At first, it seemed counter-intuitive to me, but do not adjust the HS needle other than at wide-open throttle.
When a Saito quits with a bang at high throttle settings, the HS is usually too lean..quite a bit too lean. I think the bang is a spectacular case of detonation due to the lean mixture. If they just die as you open the throttle, but do not pop or bang, you are probably too lean on the LS.
These engines will run very well when properly tuned.

William Robison

My Feedback: (3)

rlmcnii:

Thanks. You made the point I forgot to mention. The HS needle is adjusted ONLY AT FULL THROTTLE.

Bill.

rlmcnii

My Feedback: (3)

WR,
Thank you. The difficult part seems to be making oneself open the HS needle the four or five turns needed to allow the engine to run wide-open to begin with. And, not to adjust it until the engine is wide open. When a Saito is first started, as you know, it is wildly rich at low and mid-ranges. When I first started mine and listened to them running soooo rich, my intuitive reaction was to lean the HS needle. It made them run much nicer at break-in rpm's, but they would not allow running at wide open. It took me a little while to get my methodology corrected.
It seems quite a few people have the same problem when first operating these engines. rlmcnii

khodges

My Feedback: (1)

Well, I tried something different. I put the 15-8 prop on my 1.00, started it up, let it run a couple of minutes and warm up a bit, then played with the throttle some. Mind you, for now I left the needles low end about 3-1/2 and high end about 2-1/2, but the transition to upper rpm is MUCH smoother with the larger prop. I didn't have time to really play with it or run a whole tank, just wanted to see how big a difference the larger prop would make. This weekend, I'm gonna reset the needles to where they were from the factory, and start all over. I have about 55 minutes total run time so far, I think I'll go another 2 tanks(24 oz) at least before I try to fly. I guess that even when my other engines tune out at smaller needle settings, this one is not necessarily the same. Thanks again for the guidance.

loughbd

Hi Bill shall we try again?? I own at least thirty Saito engines. Do I ever get to be a member??

Kmot

My Feedback: (24)

That engine looks great! It looks like metallic, candy red paint. I wonder if it is fuelproof and he is actually going to run it? I would like to know what brand paint it is.

NM2K

My Feedback: (14)

----------------


It makes me hopping mad when I see folks so obsessed with how many TURNS a freaking needle is set at![:@]

You set the needles to where the engine runs right. It is that simple.

Manufacturers, in an effort to CTA, recommend very rich settings for the first few runs. This makes perfect sense for ringed engines, although the need may be disappearing as time progresses and machining processes advance to ever higher levels (OS). Still, too much fuel/oil never hurt anything, except in a true ABC engine. Even the latter depends upon the liner taper.

The fact that some experienced modelers know that you can vary from the prescribed break-in instructions and still end up with a great running engine should tell everyone that there is nothing written in stone about the break-in procedure, other than not to run the engine too lean. But that is true for every glow engine, whether broken-in or not, two-stroke or four-stroke, etc.

I wish you youngsters would stop worrying about how many turns to rotate the needle and actually learn WHY you rotate the needle. It isn't that complicated. I figured it out when I was a twelve year old and without much help. You can too.

Hobbsy

My Feedback: (102)

I always start my new Saitos 3 turns out, at 5 turns out you might as well pour one tank on the engine. As soon as the first 10 minutes at 4,000 is over I set LS needle for a decent idle then do the rest of the break in. I set the throttle at 5,000 rpm for 15 minutes at the end of which the engine will be running close to 5,500, then set it at 6,000 for 15 more minutes at the end of which most will be running about 6,200, that's 40 minutes and it's done. At the 5,000 rpm setting you hear the engine actually speeding up as all those parts become an engine. This has worked on about 16 Saitos.

rlmcnii

My Feedback: (3)

Ed C,
I make no claim of being an experienced modeler. My post clearly stated that I have little experience with Saito engines. The writer of the post to which I was responding seemed to be having difficulties similar to those that I had experienced. I was responding to those problems.
I understand your point about obsession with needle valve settings. However, one must start with the needles set somewhere. And, to get an engine (I believe this would apply to any piston-type engine) to run at full throttle the fuel flow must be sufficient to support that rate of combustion. Saito may well be engaging in CTA; I have no way of knowing that.
I do know that initially starting the engine with the HS needle set rich enough to support full-throttle operation, and then TUNING the needle from that setting, worked very well for me. I also know that neither my .82 nor my .91 would run full throttle with the HS needle at 1-1/2 to 2-1/4 turns out for initial running. I have no doubt that your experinces have been completely different.
Hopefully, the posters who were having difficulties are now having none. rlmcnii

PS: You may never believe this, but I figured out needle valves when I was about 12 years old also. I even know why one turns them AND in which direction to turn them. Been doing it, off and on, for 46 years. Saitos were completely new to me as of a few months ago and it took a little time to become accustomed to their particular nature. Judging by the number of posts related to break-in and tuning, it has taken quite a few experienced modelers a little time also rlmcnii

Ernie Misner

A question! Why the 5 sec. or so lag time on a 4-stroke when changing the HS needle setting? It makes sense on a 2 stroke with a remote needle. On a 4 stroke though, they die immediately with the pinch test if they are too lean. So what jwould cause the lag time?

On my 82 at WOT thumping at nearly 10,000 rpm's, it actually hurts and buzzes my fingers when they are on the HS needle to make the adjustments. Without realizing that it takes a full 5 seconds or so to settle in, I might be guilty of hurrying things a bit. Thanks for the heads up.

Ernie

loughbd

Careful Ed, I got put on moderated status for being negative and unfriendly

loughbd

rimcnii Old Navy saying. "if all else fails, read the instructions"

loughbd

rimcnii Old Navy saying. "if all else fails, read the instructions"

loughbd

fIVE SECONDS IS A long TIME. mY ENGINES RESPOND TO NEEDLE TWEAKING VERY QUICKLY.