Iflyglow

My Feedback: (79)

I can answere that, since I sold a .40A to Hobbsy. It is the same little Jewel of an engine. Horizon quit importing it to the US, but are bringing it back now.

otrcman

I have an 80 which I'm having trouble setting up to run well. The engine came to me with no history whatsoever, but I think lots of people have spun the HS and LS needles over the years. It also needed new bearings, to I've had it apart and back together.

I've read the advice about leaning the HS needle to max rpm and then setting the LS. But what about the interplay between the two needles? In my case, the LS was screwed so far in when I got it that the engine wouldn't run at all no matter how far I backed the HS out. So I arbitrarily backed the LS out several turns just to get the engine running.

Right now the engine approaches peak with the HS set at about 4 1/2 turns. Idle is pretty poor. I suspect that I need to back the LS needle out some more and then turn the HS in to get a good top end with the HS set more like 2 1/2 turns. But how do I get into the ballpark when both needles are so wildly out of adjustment?

Another question: This 80 is a biting, kicking, prop throwing brute. Bump starting doesn't work at all. With an electric starter the only safe way to start it is to remove the glo heat, get it turning with the starter, and then apply glow heat with the engine turning. Otherwise you are dodgeing props and hunting for washers each time you attempt a start. I don't claim to be an expert, but I have had very satisfactory success with a 45 and a 50.

As a side issue, the 80 begins to "cackle" a bit as you lean it out on the high end. I take that as fair warning of an imminent backfire and another prop washer search. The cackling seems to be pretty close to peak RPM, but I'm unable to lean it enough to verify the peak.

Thanks for any suggestions,

Dick Fischer

w8ye

My Feedback: (16)

The cackle is a predecessor to a backfire.

It is apparently an early 80 with the high compression.

Just go ahead and back the LS screw out to be flush with the throttle arm

At 4 1/2 turns on the HS your LS is still in too far.

Try a 13-6 or 7 prop. a 14-6 is too much

JimO

My Feedback: (7)

Have a Saito 80 and want to know if anyone has re-bent the exhaust pipe to a lesser angle. Installing sideways and would like a little more down to clear bottom of fuse,

JimO

w8ye

My Feedback: (16)

You can buy straight or 15 degree pipes for the 65, 72, 80, 82, 91, 100 engines from Horizon to replace the OEM 30 degree pipe.

Straight pipe
http://www.horizonhobby.com/Products...rodID=SAI8075B

15 degree pipe
http://www.horizonhobby.com/Products...rodID=SAI8075C

30 degree pipe
http://www.horizonhobby.com/Products...rodID=SAI8075A

There is a current style angled, cast aluminum muffler that will fit any of these pipes
http://www.horizonhobby.com/Products...rodID=SAI6574D <This one is for the 65,72, & 82

Here is the old style original straight muffler for the 65, 72, 80 & 82
http://www.horizonhobby.com/Products...rodID=SAI8074A

These are also available in the smaller 10mm size for the 50, 56 & 62 engines

otrcman

Thanks for the advice, w8ye.

I don't know how you guessed, but I was indeed using a 14-6, an old Top Flite wood. The LS screw is already backed out flush with the throttle arm, so I guess I need to go a little further. Can I expect about a 1 to 1 ratio of LS to HS ? That is, if I back the LS out 1 full turn should I expect to be able to screw HS in about 1 turn ?

One thing I forgot to mention is that this 80 seems to be an extraordinary powerhouse. It was turning 10,200 on the 14-6 when it began to cackle and I chickened out on leaning any further. This probably indicates high compression also ? I'm tempted to shim the cylinder up a bit to save hunting for my prop washer in the grass. (Not to mention trips to the emergency room from getting hit by a prop.)

Dick

w8ye

My Feedback: (16)

Not all Saito needle valves provide the same fuel mixture at the same setting. That is why they are adjustable.

I bought an old Saito 91 about four years ago that had a gasket underneath the cylinder. I removed it. The 91 never had such a high compression ratio as the early 80.

Hobbsy has a early high compression 80. He learned how to use it and never has any trouble.

You can try screwing the LS screw (The one in the center of the throttle arm) out until the idle is noticably rich and see where the high speed runs?

JimO

My Feedback: (7)

Thanks for the information. I also have a high compression 80 and you just have to learn how to work with it.

Jim

jb86

My Feedback: (8)

OS 61 FX.
http://www3.towerhobbies.com/cgi-bin...&I=LXBY46&P=SM
Crankshaft Thread Size: 5/16-24

GMS 1.20
http://www3.towerhobbies.com/cgi-bin...?&I=LXDXM5&P=0
Crankshaft Thread Size: 3/8-24

Evolution .46
http://www.horizonhobby.com/Products...rodID=EVOE0461
Crankshaft Threads:1/4 x 28

the aluminum spinner nut is lighter. the brass one is usually heavier if you need nose weight. i use the aluminum ones, like on a cub. they are from harry higley or great planes. if possible, use a lock nut. it is a thin nut that fits behind the spinner nut. on my profiles i might use an os .46 w/it's 10mm nut and then put the spinner nut over that. that way there's a locking nut and a safety spinner. don't over tighten the aluminum ones, they will strip out.
jon

TimC

Yeppers, I have a pile of them.

nitrofevr

Hey guys i would like to know if anyone has had much trouble running a 56 up side down and if so what should i expect besides a shorter plug life, and also how far away could i mount the tank and still get enough pressure

w8ye

My Feedback: (16)

The 56 runs about as well as any engine upside down.

The closer to the carb - the better for fuel draw.

GaGeeBees

My Feedback: (23)

I've got a pair of 56's mounted inverted on a DeHavilland Comet. No problems whatsoever. I have not noticed shorter plug life. My tanks are mounted directly behind the engines.

linkadrip

Thanks for the info appriciated.. on the prop hubs.. JB & w8ye

Hobbsy

My Feedback: (102)

http://www.hobby-lobby.com/spinners.htm scroll down to Kavan.

Link, have you checked these guys out, they're the best of both worlds, spinner and no blackplate plus you use the stock Saito nut and jam nut. I have them for several Saitos and they are a great solution.

linkadrip

look intresting i'll have to give them a try. and i can see there aluminum so thats good. i'm tired of plastic spinners. but will get some prop hubs too just incase, main thing is i change prop sizes so much. trying to find that one that works the best for this area. finally got some input on the type of prop s that work good in this climate here. So hopefully will come to a conclusion on what props i want to stick with and run and then i will not be messin with changing them so much. So i'll give the Kavan a shot. always good to try new things..

rlmcnii

My Feedback: (3)

l,

My Saito's run with Dave Brown spinners, a Harry Higley large-area prop nut (serves as a prop washer and first nut, actually called prop-locks?), and the spinner adapter nut as a lock nut. Have never had a bit of trouble with that set-up. One time I used a plastic spinner with an aluminum back-plate on an .82. It did not work well at all (the prop lock and lock nut repeatedly backed off) and I think it was the low quality, or perhaps inappropriate alloy, aluminum used in the back-plate. I do not remember the brand of that spinner, but it must have been a common name as I have never used an exotic spinner.

H's Kavans look good also. Good luck with whatever you work out.

mike109

G'day Love the Comet. I'd really like a DH Mosquito. A truely amazing aircraft built using ideas from the Comet.

I was reading the instructions for my Saito 120S a few days ago. One thing I noticed that I had not seen before is for inverted engines, to remove the glow plug every now and then ( I guess every couple of months of use) and clean out the plug to get any accumulated oil out of the element. They also recommend removing the tappet covers every now and then - again to drain out any excess oil that may have collected there.

I am in the process of running in a 120S inverted in a 1/4 scale Cub. So far it is running really well and seems to have great power and should have no problems with the plane. I last ran it last Thursday and will run it again in the next day or so and then I will check the plug for excess oil and report. I do not expect to have problems with the engine being inverted. A bloke round here has 4 Saito 45s in a plane called a Hannibal (I think) - all inverted and running sweetly.

bgfireman

My Feedback: (13)

If I join the saito club after 440 some pages, what number am I? By the way I have a saito 120S in a showtime 4d 90. I have been flying it for several weeks now. For some reason it would not turn up as I thought it should. I had a 15x8 master air screw so I traded down to a 14X6. Still no rpms (abot 3/4 of what it should have been). When I was cleanin up my showtime to go home I took off the cowl and one of our other flyers noticed the choke was about half open. So we closed it off and tried it again. WOW, what power we have now.

Happy flying
Alan

Hobbsy

My Feedback: (102)

Alan, it is best to remove the choke and put an O-ring in place of the choke slider, I have removed all the chokes from the older ones the newer ones have no choke.

blw

My Feedback: (3)

bgfireman- you are member #599

mike boxtall

I have a Saito125 and am running it in a little toni. Can I get a number?

mike boxtall

Is there a choke on all Saito's or is it specific to certain models? My 125 has seemed sluggish from day one. Is there a choke on it or could it be something else? By sluggish I mean only 7200 rpm with a 15X8 apc and very low 8's with a 14X10apc. Or is this normal? I am running 15% omega 4 stroke fuel. It ran well and without hesitation but I was getting my butt kicked by an old OS91 FS running the same fuel and a 12X12apc.

w8ye

My Feedback: (16)

Some time in the time frame of the later 90's they ceased to install chokes on them

RC Specialties

Mike,

That is beyond sluggish. Check to make sure the throttle is opening all the way. Make sure the tuning is correct. Hobbsy has an excellent procedure in this thread, as well as others. If you have a venturi, that could cost you rpm's. I found the 15x8 APC to be too much to keep me in the mid 9k range. Try a 15x6 or equivalent. Others may have a few more suggestions for you.

Jim