swixtt

well, you may remember me posting a question about the thread pitch,etc. of a Saito 150. the one i bought about a month ago from Great Hobbies didn't fit. it said on the package that it was 8x1.25mm i tried it on both my 100 and the 150. now Dubro has just sent me a replacement. and i can't that one to spin on either. WHAT THE HECK is going on>??? i'm at a loss because the threads are clean and both nuts that came with the engine work just fine.
any of you bought these prop nuts from Dubro before and had grief?

RCWI

HI.. i have a 220 saito with about 4 tanks through it. its inverted in a H9 p51. The problem im having is, If i get it running it will run a wile at idle sometimes up to half thrott, then all of a sudden it stops with a back fire sound and runs backwards for 1 or 2 rotations of the prop and dies. Then some times I'll start it and it fires then back fires,,, startes again and back fires again all the time wile im holding the starter on the cone. I leaned the high speed to where i can take off the glow. and the idle needle has been leaned jus a tad.
please help...i have a 82 and 125 and i thought the 220 should oparate the same.

w8ye

My Feedback: (16)

Generally the backfiring is a sign of being too lean

RCWI

i spoke with horizon today and they said it sounds like a leek in front bearing. Does this sound like its the porblem?

swixtt

Well i figured i would try threading watching very closely that it didn't screw up the threads on the engine. i used some after-run oil and slowly made a few turns.. removed.. checked...few more... removed... after i did this for about 15min. i'm able to get it on without too much issue now.?? very strange. not sure why this thread is like this. the 100 didn't turn on as hard... maybe the thread depth is more in the older 150??

w8ye

My Feedback: (16)

I leak in the front bearing would have no effect on the way the engine runs. It would only make the engine oily messy on the outside.

mike early

Hey guys, got another question. Thanks in advance!

I have a VP-30 pump, but the mounting situation is less than desirable....and I am brand new at glow engines and I figure less complicated is better for the noob.

I'd like to drill and tap my 13mm flex exhaust and install a pressure fitting. I cannot imagine that a pressure tap in the flex pipe will produce as much pressure as a fitting on a muffler, but apparently it has enough to work, right? I presume lots of folks have flown with a flex pipe/pressure fitting on their fuel tanks.

Where is a good location to install said fitting? Is heat a factor? How might someone measure whether the pressure fitting has enough pressure?

rexracer

If it narrows at the end, I would think the best place would be just before it narrows.

Oh, one more thing... Woohoo! 400 pages!

w8ye

My Feedback: (16)

My Saito straight pipes were brass. You could braze a copper or brass tube in a convenient place if your flex pipes are brass.

RPMcK

My Feedback: (1)

Mike, any auto type pressure guage will measure the pressure for you. Pressure is pressure. You would probably get the most pressure close to the exhaust port. I don't think heat would be an issue. But it would also be hottest close to the exhaust port. How much pressure is enough. Ah, that's a good question. Ron

RPMcK

My Feedback: (1)

Rex, Woo Hoo 2 (too) - to the 400 pages.

RPMcK

My Feedback: (1)

Hey Guys, Only 14 posts to go to 10,000. Yipppeeee! or something like that. Almost seems like we ought to have a party or something. Oh well, one too many glasses of wine I guess. Ron

mike early

I can hold the fuel tubing in a glass of water and see if there's enough pressure to blow out the water and make bubbles. I guess if it can blow bubbles under 8" of water, that's plenty.
I reckon?

w8ye

My Feedback: (16)

Sounds OK.

Somewhere in this forum and a couple years ago a guy measured his muffler pressure. It was more than you would think.

He did it with a tube submerged in water. I didn't find that one but I found another picture

Photo by BillS

Shack

Well, I have read almost all the 9989 posts & now know everything there is to know about Saito's.

I have bench run my new FA-72; no problem setting needles. Am awaiting LHS to get my velocity stack in so can mount on very old Top Flite .40 Cub. Will be flying with floats.

I did notice a LOT of vibration at all speeds; hope balancing prop will fix............

Please allow me to join club Saito.

Howard Shackleford

mike early

Well, two good things...our trusty Moderator has produced the answers and a great photo for free. Great Forum.
But... .25psi isn't very impressive. I presume I'll be able to get that much. Did you think it was more, w8ye? Of course more RPM=more pressure. I can see where the regulators have some large advantages on paper, with it's constant pressure. Or...maybe the pumps produce more pressure with increased RPM: either rattle-driven or crank-case-pressure-powered.

All the old timers at my field to a man suggested I get a YS110FZ. I did a lot of internet reading and trying to correct for exaggerations and boasts. I assume the YS has it's own regulator-pump thingy. A large advantage there..... I just liked the reports stability of the Saito. But that was before I knew anything about fuel delivery problems...

Hobbsy

My Feedback: (102)

Actually, most fuel delivery problems are the result of lousy tank placement, and any engine will have problems when that is the case. A Saito given half a chance and and set up properly will never have said problems and are far more reliable than a YS.

w8ye

My Feedback: (16)

One inch of water column equals .03613 pounds per square inch (PSI) and in the picture you can see that he had to add an extension to his gage. I don''t think you will see a pressure greater than 8" WC or .28 pounds pressure

mike early

Got the velocity stack installed. I would have never thought the intake is the same size on all these different-sized engines...
Makes it easier for everyone, but I wonder which engines are under carbed or over carbed....

Hobbsy

My Feedback: (102)

Fox also uses one carb for about 4 engines from .46 to .74 but the smaller ones run faster and the larger ones run slower so it works out just right.

w8ye

My Feedback: (16)

The diameter of the spray bar inside the carburetor throat reduces the actual size of the carburetor cosiderably

Hobbsy

My Feedback: (102)

If you check out SuperTigre carbs, they have about the same venturi size but the larger ones have thin spraybars and the small ones have fat spraybars.

mike early

There is only 1 place to drill and tap this 13mm flex pipe. I guess I can either put the tap at the very beginning or the very end of the pipe.
I'll try the very beginning and see how that works.

mike early

I'll see how deep I can get bubbles out a fuel line in a glass of water. And the I'll try it on the far end and repeat. I am curious. Too bad it's too late to run it in the garage....And the JB weld will not be cured.

Geardaddys

this is the 10,000th post!! Wow.. do I win a prize.. Perhaps a new saito?!