YS56 Getting seriously frustrated now..

[pgkevet]

Recap.. first engine just kept running hot..sent back etc finally popped and replaced. Second engine wouldnlt run ..went up through grades of plugs to OS7 then suddenly it started running...assumed some debris shifted in the carb system?? Anyway it was fine for a while and then started runnign hot and then the muffler cracked..replaced FOC... and assumed the lean run to do with muffler cracks.. sadly not.

So pulled engine yesterday and examined it.. all looks prety good apart from a crushed crackcase seal..replaced. Bearings clean and no notching a little varnish on pistons sides but liner clean, ring not stuck some blow-by the ports leading to tiny patches of varnish at some crown edges..all pretty good.

Today engine fires up OK but as soon as give it soem throttle it runs lean then pulses normal, lean, normal. Good tank pressure, good spurt of fuel from the inlet line...

..it's got to be something in that carb/regulator again???

I'll pull it yet again .. remove the carb and totally dismantle it an flush it all..but just about had it now.. apart from about a gallon of real flying I've shovelled another 2-3 galls of wasted fuel through these 56's engines messing about...

[robgt]

Clean out the regulator being careful not to lose the spring!
Don't remove the white plug on the regulator (to fiddle with the setting there) as you will _never_ get it to run right if you do.
If that doesn't sort it (and you know your needles are set correctly) try altering the tank pressure - fist stop is to remove the little metal "top hat" shaped piece from the one way check valve. After that, shorten the tube between the backplate of the engine and the check valve (standard 3cm - try 2.5, then 2, etc).

Which muffler are you using?
Cheers
Rob

[millerman]

nice to see yet another satisfied YS engine customer

[Swashbuckler]

Had the pulsing thing on two of these, first one went back, returned the same, so back again. Returned and appeared to work fine and then the conrod snapped within a couple of flights. Replaced engine after some arguments. Latest one did pulse after a couple of gallons so I dismantled the carb and reg and reassembled, been ok since. So I'd agree with your assesment that its the reg.

[stunks]

get and align or os engine

[Geek]

What fuel have you been using?

[shikari_chaos]

I was just going to say fuel too! I had lots of engine trouble recently due to fuel! grrr a new bottle of Optifuel solved all my worries well except an annoying one way bearing

[pgkevet]

Rapincon 30 and I've now had enough experience with pressurised tanks to know the tank pressure was good today...

[pgkevet]

I was just going to say fuel too! I had lots of engine trouble recently due to fuel! grrr a new bottle of Optifuel solved all my worries well except an annoying one way bearing

I'm using the same fuel in two other helis without issue..albeit they are both 90's. But can sympathise.was a lovely day and the other heli I took had a slipping starter cup with worn machine screw ends that didn't fit into the dimples.. so a couple of hours of cold fingers and no flying

[pgkevet]

..pulled the engine, dismantled the carb and flushed everything with fuel a 20ml syringe and tubing. Not really found anything to blame apart from perhaps a miniscule discolouration on the paper towel when flushed through one needle housing...we'll see...but if it isn't running tomorrow then i think I have to admit defeat.
Noteworthy that the high needle was less sticky when replaced.. lubed by the fule oils no doubt. Reset to factory defaults..

[Cuppa]

Luv my ys56sr in my 600n, always run it and my 700 on wildcat LV 30% no problems with ether the ys56sr or the OS91HZ-R. also tryd rapicon 30% ok but stains the inside of the motor! Magnum stinks n burns your eyes, opti good but a little corrosive on the motor and coolpower well bit dear!
oil content would want to be arround 23% for a longer life out of your motor which ever fuel you choose

[pgkevet]

Luv my ys56sr in my 600n, always run it and my 700 on wildcat LV 30% no problems with ether the ys56sr or the OS91HZ-R. also tryd rapicon 30% ok but stains the inside of the motor! Magnum stinks n burns your eyes, opti good but a little corrosive on the motor and coolpower well bit dear!
oil content would want to be arround 23% for a longer life out of your motor which ever fuel you choose

Apart from the varnish on the pistons the rapicon hasn't lead to any discolourations inside.. and as you know is 23% oil. Then again probbaly only 3-4 gallons thruogh this and only two third of that flying rather than pi$$ing about.

Every brand or everything has complaints...sometimes user inabilities, sometimes manufacture quality..and every brand has some good stories. When it works it's a fine engine with bags power but for the amount of issues I've had then there's either a design flaw or a high maintentnace requirement (even if that's just regular cleaning of the check valve)

My working theory/hope is that there was soem microscopic debris in the high needle system from the regulator reservoir..we'll see....

[pgkevet]

Update

Cleaning out the reg and carb had stopped the pusling..but now the tank pressure isn't high enough. It gives low smoke at idle, good smoke to about half throttle and then the smoke drops off badly and the carbsmart richens fully bt it starts to get hot. High needle opened a full turn from factory settings doesn't help and definately not enough hiss when pressure released. I pulled the 'top hat' but no difference, the check valve sucks through well.

I'll run a pressure test on the tank system but not optimistic that I'll find a nice easy fix.

It'd be nice to have the sort of data one needs here..the ability to fix a pressure test directly to the crank, the bility to know the ideal fuel pressure so one could run a gravity line for a bench test or pressurise a tank with meter etc.

It'd also be nice to have a prop adapter and test on a bench rather than (keep taking it in and out) in the heli. I do wonder whether a new ring and bearing ..even though they look OK might help..but equally loth to chuck more time and money at it.

If the tank pressure test doesn't give a causee then shortening the line to check valve for a last test before going OS might get this heli in the air...it's costing money just on test fuel and blasting around the sky with 90's when I could do the practice on a .55...

[Andy from Sandy]

It'd also be nice to have a prop adapter and test on a bench

I have one and the woodruff key that came from an OS 50 sx (non-hyper).

[pgkevet]

I have one and the woodruff key that came from an OS 50 sx (non-hyper).

There's no slot that I recall on the YS56 crank..it'd have to be a direct bolt and clamp..but my patience is thin...