Wrote off my OS 105HZR

[choppaholic]

Early this year I bought a 105HZR, what appears to be a curse more than an engine. When I got it had loads of regulator issue, always cutting out mid-flight costing me a nice set of edge blades and a lot of tinkering, a 100ish pound service later on my regulator. The next two flight went ok, then cut out mid-flight with almost bogging itself to death on a rainbow reversal. What appeared to be a dead glow plug, did exactly the same thing on the second flight this time with a bang clonk, clonk, and nasty auto to safety, having killed an OS50 during my initial nitro days I knew pretty much what that was about. guess the first glow plug burn out was the clue to start with as it was coverd in gray matter what was basically fine pieces of ally being thrown at the plug from the piston. So now I have burnt out piston with a big hole in it and scored liner. Looking at the cost of a new linear, piston, bearing and ring etc…I am going back to my spare 91HZ for now.

Now what is suspiciously wrong is;

My needles are 2 1/4^th on the main and 1 ¾ on the high so I am running super rich. This is with a Hatori muffler it came at about 2ish turn I have tuned it to the richer side as it was running way too hot for my liking and flew fine for the few flight I have had with it (count that to be about 5), It made good power so I hadn’t got to tuning it lean yet or not that it gave me a chance. So how can it run lean, it must be super rich unless the regulator had something to do with it again. Having tried all know tricks on the net to check regulators, it appears to be working correctly.

Next up I bought some stainless steel bearings from RCbearings which appear to be completely rusted, so much for stainless steel, they will be hearing from me shortly. I doubt that this would be the cause I have seen worse rusted bearing in nitro cause very little issue.

So I am baffled as to what’s has gone wrong? any ideas would be much appreciated.

When I first started in this hobby one of my club mate use to say nitro’s either work for ever or they are your worst nightmare, comes back to mind. Had a few nitros now running for ages without touching the needle once and some that won’t let me sleep at night

[atomiccomp]

Is it possible the regulator is still duff? maybe running inconsistently giving you a lean run? A couple of lads in our club have had problems with the OS regulators.

I agree with your mate, I have had 3 nitro heli's the first a os50 hyper in a trex 600 was a nightmare. tricky to start low power and it did 2 pistons and liners no matter how it was setup. The second another os50 Hyper in a compass 3d+ was fab, started first time and always ran consistently and had all the power you would expect from a os50 hyper. My third an align 91 is a cracker, starts first time and runs great on 25% nitro.
I think it's a lottery with nitro's especially if you don't buy them brand new. However at £450 for the os105 and pipe, they ain't cheap!

[hedge]

Sorry to hear this, sounds like a fuel problem quite a few Qs but here goes

1) What fuel - Brand, % and Age
2) Before replacing all tubing please measure the length of tube from the rear of the crank to the one way valve
3) Please post a pic of the one way valve
4) What clunk pickup do you have? Felt, Foam, Just metal, Bubbless
5) Do you have a header tank - please post picture of it
6) Do you use inline fuel filters? Check them if you do and look for correct orientation and also them being blocked.

While the reg is a simple device it is NOT a serviceable part - according to the manual. So when you do look at it be 100% sure when you reassemble not to pinch the seal against the metal and to put it back the right way around.

That's my list for now other areas are leaks around the carb and blocked carb needles. This is not that hard to strip down but there are areas which have grease that can look like it needs removing - I am never sure wether to or not

[choppaholic]

Thanks guys for the response, here’s some I can answer, no point on pics as its completely stripped out now.

1) What fuel - Brand, % and Age

Opti 20% age 3 months at home dont know how old at dealer, but my other engine OS 55 has been drinking the same stuff with no issue for last 3 months

2) Before replacing all tubing please measure the length of tube from the rear of the crank to the one way valve

Tube was all new 5 flight ago when I change the engine to a 105, the distance on one way to crank is 10cm, also last flight something odd was that it had loads of pressure in tank, more than what it use have before, hissed like mad. When I unplugged the feed pipe to the carb to check if fuel was actually flowing correctly to the carb while tank was under pressure it was a nice fountain so flow is good no blockage in line

3) Please post a pic of the one way valve

It’s an OS one way and connected correctly arrow wise, as the top point may clarify the pressure is building

4) What clunk pickup do you have? Felt, Foam, Just metal, Bubbless

Clunk is standard align metal one, when failure happened, tank was 3/4^th full or 1/4^th empty

5) Do you have a header tank - please post picture of it

Yes header tank Quick UK with again metal clunk, located next to main tank as normal.

6) Do you use inline fuel filters? Check them if you do and look for correct orientation and also them being blocked.

Yes inline filter both after one way valve and before carb inlet, new at the time of engine change and are clear.

Regulator not touched after service so unless they put it wrong, but it appears to work correctly, at least stops fuel and pushes on vacuum

Might just strip the whole carb out and check needles now as it pretty much a bin job now not going to rebuild it.

much appreciate the response guys, thanks

[KevDavies]

A few things I can advise on here.

Throw the header tank away, it causes all sort of shyte on the 700 its not needed.

Clunk you need the Lynx MOAS or the OMI fuel magnet (if using the lynx you need to add weight to it as its only light I use a spare crank nut over the nipple, also holds the pipe on)

Use the thinnest clunk line you can find, the ripmax stuff works bloody wonders

Also for inline filters they can cause air leaks, the only one ive found that doesnt is the sullivan crap trap.

Alternatively, if you need the internals looking at on the engine, I am more than willing to provide this as a free service, you just send any parts that are required.

Hope some of this helps

Kev

[hedge]

Nothing to note there. I don't run a header and switched from Lynx moas to omi foam as I prefer it. My filters also leak a bit but not detremental - I am removing them however. Can't be sure how you can check for air leaks but that would be my next stop.

[torque to twist]

Bearings

Nothing to note there. I don't run a header and switched from Lynx moas to omi foam as I prefer it. My filters also leak a bit but not detremental - I am removing them however. Can't be sure how you can check for air leaks but that would be my next stop.

If you want to use stainless bearing make sure you get a 440c grade, I use boca bearings.

Has anyone had good luck with the centre glide bush from morgan fuels (I think)???

Cheers

[choppaholic]

Thanks for responses guys,

One thing confuses me, this is my first regulated engine are these that temperamental because my 91Hz with the same setup (ofcourse without the one way), works flawless. What is it with these regulators.

In terms of air leaks I don’t know either how to check, when I bench ran it on first install there were no air bubbles in the line and none that I noticed when I autoed it down as it was the first thing I checked (may be it was doing something in the air but not on the ground), also doesn’t the regulator take carer of this as it has a tiny reserve of fuel that it regulates.

Regards stainless bearings, they have either sent me the wrong ones or pulled a fast one on me, the last one in my 50 never showed any sign of rust after 2 years.

Clunk line it is the Ripmax ultra thin clunk line that I use.

I will take the needles off and inspect may there lies the issue, I am not entirely sure the fuel supply is the issue. To me its either the reg or the carb

[horneteer]

Sorry to hear about your troubles. My OS 105HZR has been pretty much trouble free but I have heard about problems with OS and YS regs in the past. I wonder whether they get gummed up and sticky or what. You might consider sending your engine to OS or their UK distributor with a strongly worded cover letter, with a view to getting it repaired and tested for free or at a heavily discounted rate.

I have also tried a stainless rear bearing from RCbearings.com. Didn't seem to last much longer than a plain steel one before the surface rust became unacceptable. I now just regular SKFs or similar with a riveted cage and change mine out every 6-12 months.

Hope you get it fixed without too much further agro or expense. Its a great motor when it works.

[eddie1293]

Please don't quote me but I was reliably informed by someone who has a vague connection to Ripmax that they are aware of a piston problem with these engines i.e. holes appearing in them. Put the bits back in a box and return it to them with a polite covering letter

[dszabo]

Umm, I was about to bite the bullet and buy a 105 and pipe, this has put me off a bit

Hope you get it sorted.

[GIXERMAN]

Umm, I was about to bite the bullet and buy a 105 and pipe, this has put me off a bit

Hope you get it sorted.

nothing wrong with 91 dean, it all about the collective

[waveydavey]

I wouldn't let it put you off Dean, they're a great engine although when the ring pin goes it does to tend to cost an arm and a leg. I've got 2 and cross my fingers they've both been good as gold. The first one I'd sent back to Ripmax after I complained to OS about the pin going, they've rebuilt the engine and it's been good ever since. It's had a bearing and on the strip down everything looked good.

Chris is running the TT 100H in his G4 and now DFC and it runs well, plenty of power and reasonably easy to tune once you get used to it. The other alternative is the YS but from my experience I wouldn't go near another one, had 2 and never got one to run right.

[j2tgw]

Well I bought a brand new 105 with power boost pipe and I cant get it to run right ?
sounds like a 50 on steroids ?
Thought it was the pipe . so bought a Hatori for it ,still the same ,
Its gutless ive tried everything with it that I can think off ,
I have 5 ys 120 sr,s and they run great with loads more power than the 105
I also have a ys 120 srx brill engine
My os is for the chop I think
Will stick with ys from now on !!

[waveydavey]

Strange isn't it my experience with YS was 3 months of fiddling and no flying, couldn't get one to run right. Brand new engines and both pups, ended up with a lean run on one and destroyed the piston and that was then end of my helis equipped with YS. The OS on the other hand have been fine apart from the issue with the ring pin