smoknrv4

My Feedback: (11)

PLaying with my YS .45, and I don't have much experience with the YS engines, is there a low end needle setting on this engine?? It runs nice, turns a 10-6 APC at 14800 rpm, with a stock muffler, but transition from idle to full is real hesitant, any help would be appreciated.
It might be going in my next SD, but I'm going to pipe it, and get rid of the stock muffler, I've heard some good things about these engines.

freakingfast

My Feedback: (3)

First, before you do any tweaking, put a fresh OS#8 plug in it.

The low speed adjustment is done by the brass regulator screw on the bottom, this also controls the overall pressure as well so if you change it, you will need to reset the high speed needle as well. To lean the regulator, turn it clockwise, use 1/8 turn increments. In most of my engines, this screw is just below flush.

In the future, if a good setting works and than later on the idle or top end go bad, always try a new plug first. Once set I almost never touch the regulator screw and I may only adjust the high speed twice a year, winter & summer

Set the high speed needle a bit to the rich side as these engines tend to lean out in flight.

The 10X6 is good for starters try a 9X9 or 9X8 later.

smoknrv4

My Feedback: (11)

Thank you very helpful, will try new glowplug first.

freakingfast

My Feedback: (3)

These engines are a bit picky about the type of plug. Get it working on the OS#8 (benchmark). Later test a K&B HD or Enya #4-#5 for better endurance.

smoknrv4

My Feedback: (11)

put a new plug in it(O.S.#8) then adjusted the reg, and it ran sweet with nice transition now. I also tried a 9-8 prop, because the engine is already broke in, and I got a little over 15000, what kind of peak RPM is to be expected with a properly tuned pipe, on this engine?

freakingfast

My Feedback: (3)

With an APC 9X9 a good engine (good bearings & piston not too loose) on 15% fuel with a properly tuned pipe should see about 16,300 on the ground. The 9X8 should be about 16,900 when tuned for it. These are peak readings, back off for flight.

The 9X9 is my favorite on a delta, but some guys like the 9X8.

smoknrv4

My Feedback: (11)

These engines seem a bit heavy compared to a OS 46 FX, although I haven't weighed it yet, what are some of the advantages of this engine over the others?

freakingfast

My Feedback: (3)

They are very robust, built to put out higher levels of power for a long time and there is the pump system weight involved. For example in mass and crank pin size, the connecting rod dwarfs a Webra 55's. And whats priceless is consistent flights, once adjusted it should have the same fuel mixture from start to end.
About 2 oz heavier than a Jett or Webra 50 and 1 oz. more than a OS 46 AX. Compares well only to a Jett for both longevity and power.

freakingfast

My Feedback: (3)

Make sure you put a 1/4" thick piece of urethane foam rubber http://www.shopatron.com/product/part_number=513/101.0 under the fuel tank and some pieces around the perimeter down below to keep tank from contacting the top deck. Don't over tighten the tank restraining strap. Don't use ethylene foam for any thing RC(white stuff that electronics are wrapped with) it has poor vibration absorption. A good fuel tank is a Hayes 8 oz. regular, it can take the pressure easy. http://www.horizonhobby.com/Products...?ProdID=HAY070

smoknrv4

My Feedback: (11)

Sounds like a sure winner! I guess the tank pressurizes when running doesn't it, therefore needing padding and a little extra expansion room.
Thanks you have been very helpful.

MJD

My Feedback: (1)

I'm curious, is there any reason not to use a Jett or Tettra bladder tank with the YS setup? I wondered if tank pressure is too high and they blow stoppers or something, or are they fine to use as well?

MJD

smoknrv4

My Feedback: (11)

I think a bladder tank could take the pressure, but with a pumped engine is it really neccesary?

MJD

My Feedback: (1)

Do pumps eliminate air bubbles? That's not rhetorical, I don't know. If not, then pumped or not is irrelevant.

Mike

combatpigg

My Feedback: (3)

The deal's OFF if the YS blows up the bladder tanks.

I think it wouldn't hurt to put strapping tape around the Tettra tank housing. The pump pressure would put a squeeze on the inner bag, but I'll bet it wouldn't rupture because the fuel inside isn't compressible.

Does the pump ever get gummed up?

IIRC, didn't one of the fuel companies have a special mix just for YS? Powermaster? Maybe I'm thinkin' 4 strokes?

still4given

The YS doesn't actually have a pump. It uses crankcase pressure to pressurize the tank and a regulator to meter the fuel. I have been told that the 8lbs of pressure in the tank helps reduce foaming so a bladder tank is not as necessary.

MJD

My Feedback: (1)

Hmm, when the small air bubbles at 8psi reach the other side of the regulator at maybe 1/4psi, I think they would get big again. But anyhow, perhaps there is other magic at work that improves the situation. In any case, they run on clunk tanks.

MJD

freakingfast

My Feedback: (3)

The padding is for reducing vibration in order to keep fuel foaming down, like any other high revving engine can do to fuel. Guys stuffing a tank tightly between the formers have been surprised when the plane’s sides are busted out when the tank swells, so give it clearance.

Bladder...see below.
They have been known to pop the stoppers and split tanks on cheaper or poorly made tank styles.

Only somewhat, like a soda before you open it, or a pressurized radiator, but it’s still good to isolate the tank.
The pump is mainly there for a stable fuel pressure to the carb.
There is a mix of air and fuel in the return line, so it just wont work with a bladder tank(inside or outside of the bladder.) Small amount of fuel on the outside of the bladder will degrade it quickly.
The pumps can get gummed if it flown only a few times a year and fuel was allowed to sit in the engine but most of the time I have found dirt in the used engines I’ve bought on line, from likely cause, poor fueling hygiene.

I think your thinking of YS 20/20 and that's for the four strokers. Feed this one 15%nitro with some castor in it's oil make-up. Most engines will take up to 30% nitro with a cooler plug, but it's mainly up to the clearances and tolerance build up in the individual engine so head shimming may be needed. I think you will find the 15% has plenty of performance.

combatpigg

My Feedback: (3)

The only YS .45 [maybe it was a .60] I ever saw was 15-20 years ago and the guy had it on rubber mounts. It sat there at idle and shook like it was possessed, but would calm down when he nailed it. It was mounted in a dog of a plane, too bad. I haven't had any experience with the rubber mounts, it's a pretty scary sight to see that much power wobbling around like that [:-].

MJD

My Feedback: (1)

[/quote]
There is a mix of air and fuel in the return line, so it just wont work with a bladder tank(inside or outside of the bladder.) Small amount of fuel on the outside of the bladder will degrade it quickly.
[/quote]

Well that makes sense, it would sure be more work dealing with fuel p-ing out the vent line as you syringe-fill. I think the bladder in Jett tanks are a plastic film - and if so I can't see why exposure matters to those. Do some use latex bladders? And in any case, maybe I'm missing something but I don't understand why fuel exposure on one side matters, but on the other side of the same bladder doesn't matter?

In any case, I'm not trying to be curmudgeonly - I'm only asking because I wanted to know if bladder tanks should be avoided for some reason I didn't know - it's good to know these things.

MJD

combatpigg

My Feedback: (3)

MJD, your post leads to the question......how often should the liners get replaced? Tettra's instructions are in broken English....you would think they could afford to hire an 8th grader with a B average in English to proof read their instructions? They mention cleaning out the area outside of the bag once in awhile..I don't remember exactly how they phrased it.

MJD

My Feedback: (1)

I can imagine all kinds of childish replies to that one.. .. but I haven't even hit the showers yet myself this morning.

Flushing with methyl alchohol or mebbe FAI fuel might be the ticket, if indeed it is a rubber bladder. It may be they simply suggest getting all the exhaust spooge cleared outta there once in a while. Sounds like a job for the lazy to use an electric fuel pump, in/out/in/out from a quart of whatever you're flushing it with.

MJD

still4given

The 45 is not like the 4strokes. There is no line beyond the regulator. It is integrated with the carb and goes directly from the regulator to the venturi. I'm not saying that it completely eliminates foaming, but the tendency is much less under the higher pressure.

I have used a Jett bubbless tank with mine and it worked fine. I'm just not convinced it is needed as long as you properly isolate the tank.

There is more fuel coming from an exhaust nipple on a standard 2 stroke, than the pressure side of a YS. The bladder is full of fuel. Fuel on the outside of the bladder will not degrade it.

Blessings, Terry

evan-RCU

Nitro in the fuel over time will degrade the bladder.... The high the nitro the quicker.

bob27s

My Feedback: (19)

You can not use a bubble tank with a YS. The YS pressurizes the tank, AND it returns fuel to the tank. You can not return fuel to the bubble-jett or tetra, since the pressurized side is on outside of the fuel bag.

One thing on YS tanks - wrap it with fiber-reinforced tape. Keeps it from expanding too much, provides more consistant pressure, and on some tanks will prevent it from splitting over time.

Bob

combatpigg

My Feedback: (3)

How does the YS .45 compare with the SJ .46? On one of these 32 inch deltas.