NapaFloyd

My Feedback: (1)

Saito 150 with over 2 gals of fuel ran thru it.. Have tried adjusting low end according to the manual.. to no avail.. Adjsusted the Valves to factory specs...

Last time I started it and at low idle OK... then tried a high speed transition and backfired and threw the prop, nuts and washer.. only thing I found was the prop... VERY DANGEROUS..

Engine is mounted inverted and previously had a on board glow... the engine started to give me problems back fireing so removed it thinking it was the on board glow...

What I need is advise.. First .. what is the initial factory setting for the low end.. the manual states to richen the mixture turn the setting clock wise.. if this doesn't try turning counter-clockwise... Hmmmm..

Floyd in the Republic of Panama....

blw

My Feedback: (3)

Sounds lean. If it is backfiring on the way up to full throttle, richen the low speed needle valve a bit so you can run up the engine. Advance the throttle slowly. Set the high speed a few hundred RPMs rich from where it peaks.

TimC

NapaFloyd, to richen the low speed mixture turn the screw counter-clockwise. Here's the factory setting given by Hobbsy on where the head end of the adjustment screw should be:



"Metal throttle arm even with end of barrel, plastic throttle arm, 1/16th inch inside the arm, in both cases it is only a rough starting place."

loughbd

When a 4 cycle back fires and throws the prop, 99% of the time it's lean on the high end. Also check the intake pipe for air leaks.

gjeffers

napafloyd, like blw said its more than likely lean, but if its idling id just turn the low end screw only 1/8th turn in the direction timc said,counterclockwise and re try it, i think this will help with out going to the beginning and starting over

NapaFloyd

My Feedback: (1)

TMC, you know that my book that came with the engine reads clockwise to richen.. Hmm.. must have been in the translation to english... clock became counter..clockwise..

Thanks to all.. I was ready to use the Saito 150 for a fishing weight...

TMC, From Lone Pine, CA.... do you happen to know David Figuroa of The Calif. Dept of Fish and Game ?? He lives and hunts in that area.. Also a black powder guy...

Floyd... past resident of Napa Valley...

TLH101

My Feedback: (90)

If needle adjustments don't fix it, try fresh fuel. A friend fought a saito .91 with the same problem. Constantly threw the prop when accelerating. Even when "blubbering" rich. He was ready the throw the engine away. Then we tried fresh fuel, and it was like a new engine. Been running perfect ever since.

w8ye

My Feedback: (16)

Get yourself a USA/Canada version of the Manual here...

http://www.horizonhobby.com/ProdInfo...der_Manual.pdf

Hobbsy

My Feedback: (102)

One other item Floyd, if the low speed needle is too lean you can screw the high speed needle out 10 turns and it won't do any good. The Low speed is not a needle at all but a sleeve that moves in and out over the cats eye slit in the spraybar, if the sleeve is too far in it basically negates the high speed needle.

NapaFloyd

My Feedback: (1)

Hey, thanks to all.. the cuss words have been elimated.. hahaha

But the help has been great.. My Dragon Lady thanks. you..

Picks to follow after she is fixed...

Floyd in Panama

NapaFloyd

My Feedback: (1)

w8ye, it is the same in my book.. if you turn it in clockwise you lean it out... I tried to richen it by screwing out... got the idle OK.. did a transition after it got warm.. then flew a couple of turns around the field.. low on fuel .. landed and fueled up.. let the engine cool..

Started it up again.. idle OK.. then did transition to high.. and blew the prop 35 feet just missing a 46% Ultimate.. of course lost all the nuts and washer...

Got to believe the timing is off..

Used new 15% fuel etc... new nuts etc... more $$

Bummer...

Will be in the states in November.. will ship it to whoever you recomend... then...

Floyd.. in the meantime will hang a OS 120 on the Dragon Lady...

w8ye

My Feedback: (16)

Back out the idle mixture screw a half turn.

Try to set your high speed needle

It is going lean on you during your transition to High speed. Have you tried opening the high speed needle?

Steelie

My Feedback: (18)

I am having the same exact problem with an OS .70. Inverted using Powermaster 20 20. Props and prop nuts all over the field. Yesterday prop and associated hardware hit me in the stomach on startup. Tried various needle settings with no success. I'll richen the low today just to see. Last 4 flights cost me $42 in props, $18 in spinner and my stomach managed to stop the nuts!....found them.


Steelie...with a prop bruise.

loughbd

Try less nitomethane and richen the mixture a bit.

buzzingb

My Feedback: (2)

Save yourself a lot of grief and work, find someone who runs Saitos and get them to help you. Setting the needles aren't as easy as you would think and you will need help for the first time or two. Many people have problems setting the needles even experienced people so don't hessitate to ask for help. Once set the Saito engines are great and the great part is what you want so get it over with so you can enjoy the great power and running characteristics. M

flyinrain

My Feedback: (25)

What size prop are you using and what type of glow plug? Also where is your high end needle valve set at. If it is too lean that will also cause your problem

Steelie

My Feedback: (18)

The idea of less nitro is where I will try next. I emailed Conley-Perry and asked if their oscillating pump would help with the flooding (tank is a little higher than I would like it) and they suggested to mount the engine upright and that would fix my needle adjustment problems and probably would stop the backfiring as long as I am not lean. Sounds good. The engine has high compression so maybe the Powermaster 20 20 might be detonating. Today I reset the low needle to factory and the high to 1/4 turn fat. Backfired. I have a Fox plug if that matters. The OS plug that came with the engine did the same thing. 13 x 4 APC 3D prop the whole time. Tomorrow back to the field.



Steelie

NM2K

My Feedback: (14)

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Try placing an extra glow plug washer under the glow plug. If this reduces the problem, your engine may be overcompressed. Factory variances might be responsible, carbon build up in the cylinder might be responsible. A colder plug might be of help, less nitro, less propeller load, etc.

Running inverted requires much finer carb adjusting, which can be quite evasive. This improves with running time - usually.

Hobbsy

My Feedback: (102)

Some four cycle plugs are already dangerously short on thread engagement, plus the change in combustion chamber volume is too miniscule to matter.

NM2K

My Feedback: (14)

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I agree that it would not be a good idea if you are running short glow plugs. But a Saito should be ran with an OS Type-F, or Saito equivalent. True?

Sometimes the change in combustion area is not enough to cure the problem, but it is enough to show a trend. I'm back into diagnostic again, old friend.

loughbd

Try an Enya #3. It's the only plug I use. It's also the one of two plugs that YS recommends. The other is the OS Type F. The Enya is cheaper. Enya also has plugs ranging from the #3 to the #6. They get colder as the number increases.

I was introduced to Enya glow plugs while living in Japan. It was the plug that 90% of the Japanese used.

Hobbsy

My Feedback: (102)

No sir, I use Fox Miracle plugs almost exclusively and they do the job perfectly. They work in YSs, Lasers and Saitos equally well, you're right about the latest Saito plug, it works quite well so far. The Glo-Devil 4C Special is also a great fourstroke plug but has the least amount of threads.

JettPilot

My Feedback: (6)

Forget clockwise, counterclockwise, the needles are always screw in to lean, screw out to richen the mixture. If you did not know that, you should not be running any gas engine.... Maybe a kite and string would match your skill level better

Jettpilot

Phil Heller

My Feedback: (9)

The early 150's had a high compression ratio and did not like high nitro content. Backfiring and prop throwing were a common ailment. They ran fine on 5% or 10% max. Also a 13-4 is quite small for a 150. A 15-4 wide blade would be more like it. I use a 16-8 on my Enya 155 and it turns at 8000!

Phil

OOPS! Sorry on the prop size, got you mixed up with Steelie and his OS 70!

Phil

pauln28

My Feedback: (2)

I can relate to your problems your having with your engine. I had bought a Saito 1.50 last year and this was my first 4-stroke. mine is mounted inverted as well. Besides all the other advice everyone else gave you (which is all good) I can only tell you what helped me. First of all Saitos website is a good place to start I did alot of reading on there. I also switched to an O.S. type F and that helped smooth my idle a bit. I run 15% fuel, 16*8 prop and I get about 9,000rpm's. Just takes alot of patience, especially with an inverted engine, adjusting the needles. I knew Saito makes real good engines and that's what kept me at it. Mine runs fine now, I can prime it and it will hand start on the first or second flip.