OS105HZR Tuning help

[Planehazza]

Hi all,

A bit confused about how the needles work on the OS105HZR. The manual seems to indicate that the HIGH needle affects the whole range, as opposed to the top 15% like others.



Also, I know it's subjective, but I'm struggling to set starting values to the needles. I'm going out flying tonight where it's warm and humid, so I'll need to run leaner than normal, but I don't want to overdo it. I'm thinking 1 1/2 turns on high, and 1 turn out on mid?

Thanks!

[George J]

Those settings will get you flying but going to be rich on both I'd guess Harry. I think I'm at about 3/4 on mid and around 1 on the high needle and I've not flown today but would think I'd be in another click or two on the high needle at least.

Rich isn't an issue though on the 105 and it's better that way as you know!!

[waveydavey]

It's strange how I think the mid needle settings are lean as a lean thing. Ive read countless threads with people 3/4 to 1 turn out and I just can't run like that. Using a power boost and 20%, anyone know why. I would say that 1 1/2 on the top is about right but maybe a bit rich but the mid comes all the way out to 1 1/2 to 1 1/4 for me.

[Made2Fade]

Harry its a case of going through the motions and flight testing it... doing climbouts to set your high end etc Everybodys setting will be different. I remember Stus settings on his were mental... when i dialed them into mine as an experiment they were lean yet on his they worked fine. Same fuel at the time too (Rapicon 20%). Your best just flying it... Tim Jones done a very good video on setting the YS120... the general procedure is exactly the same mate He shows you how to actually listen and look at the model to find out what needle to tweak. I learnt a trick or 2 from watching his video a year or so back and ive been flying nitro helis for some time now as you know (so not exactly a stranger to tweaking engnes).
Your current settings will be well good enough to get it flying, just simply go from there.
Heres the video -

[Stuart]

It is a dark art engine tuning. I come from an era when we only had two needles then the first OS with a mid range we just closed it and kept to the old school of using the high needle to alter the tuning.

Then when I got the 105 I opened it up to a 1/4 then set the main from there and just tweaked after each flight. Always checking the engine temp with the finger on the back plate and using your ear...

[Delarado]

Yep 3/4 for mid is way lean for me too. I think I'm something like 1.5 mid and 1.5 high, sometimes even as far out as 2 on the high.

[Made2Fade]

Im about 1&1/4 on mid and 1&1/2 on high needle fwiw Harry using Opti 20 or Coptermix 20 (very similar fuels for tuning).

[Planehazza]

Yep 3/4 for mid is way lean for me too. I think I'm something like 1.5 mid and 1.5 high, sometimes even as far out as 2 on the high.

Yeah some of the settings I've been reading are crazy lean, however I suspect yours is the none regulated version? The regulator forces more fuel effectively richening the mixture. Some of the yanks in the summer have the needles almost closed!

Harry its a case of going through the motions and flight testing it... doing climbouts to set your high end etc Everybodys setting will be different. I remember Stus settings on his were mental... when i dialed them into mine as an experiment they were lean yet on his they worked fine. Same fuel at the time too (Rapicon 20%). Your best just flying it... Tim Jones done a very good video on setting the YS120... the general procedure is exactly the same mate He shows you how to actually listen and look at the model to find out what needle to tweak. I learnt a trick or 2 from watching his video a year or so back and ive been flying nitro helis for some time now as you know (so not exactly a stranger to tweaking engnes).
Your current settings will be well good enough to get it flying, just simply go from there.
Heres the video -
<snip>

Yeah I need to watch that again, good video.

It is a dark art engine tuning. I come from an era when we only had two needles then the first OS with a mid range we just closed it and kept to the old school of using the high needle to alter the tuning.

Then when I got the 105 I opened it up to a 1/4 then set the main from there and just tweaked after each flight. Always checking the engine temp with the finger on the back plate and using your ear...

Im about 1&1/4 on mid and 1&1/2 on high needle fwiw Harry using Opti 20 or Coptermix 20 (very similar fuels for tuning).

Cheers for the help all. I still remember mostly what to do, it was just that I had no rough ideas where to put the needles as the suggested settings vary massively on this motor for some reason. I flew it last night and it didn't sound great, but it came down only warm (lots of full power climbs/descends to get the high needle going), but I think I forgot to arm my governor...

Using opti 20SLV, are your HZRs VERY smokey? Mine caused a fog on the field it was that smokey!

[wadders248]

Using opti 20SLV, are your HZRs VERY smokey? Mine caused a fog on the field it was that smokey!

I use exactly the same fuel and can leave a good thick layer of fog at the field... nice to auto through it at the end!

The engine seems to be running about right, just makes quite a lot of smoke if there's no breeze.

[Planehazza]

Harry its a case of going through the motions and flight testing it... doing climbouts to set your high end etc Everybodys setting will be different. I remember Stus settings on his were mental... when i dialed them into mine as an experiment they were lean yet on his they worked fine. Same fuel at the time too (Rapicon 20%). Your best just flying it... Tim Jones done a very good video on setting the YS120... the general procedure is exactly the same mate He shows you how to actually listen and look at the model to find out what needle to tweak. I learnt a trick or 2 from watching his video a year or so back and ive been flying nitro helis for some time now as you know (so not exactly a stranger to tweaking engnes).
Your current settings will be well good enough to get it flying, just simply go from there.
Heres the video -

It is a dark art engine tuning. I come from an era when we only had two needles then the first OS with a mid range we just closed it and kept to the old school of using the high needle to alter the tuning.

Then when I got the 105 I opened it up to a 1/4 then set the main from there and just tweaked after each flight. Always checking the engine temp with the finger on the back plate and using your ear...

Im about 1&1/4 on mid and 1&1/2 on high needle fwiw Harry using Opti 20 or Coptermix 20 (very similar fuels for tuning).

I use exactly the same fuel and can leave a good thick layer of fog at the field... nice to auto through it at the end!

The engine seems to be running about right, just makes quite a lot of smoke if there's no breeze.

Cheers mate. May I ask what needle settings you've got?

[wadders248]

Cheers mate. May I ask what needle settings you've got?

My motor is the OS91 so not sure how comparable, it's also got a regulator. The needles are at 3/4 mid and 1 3/4 high...

[Made2Fade]

Mines not overly smokey so probably a small clue that you are running rich which is a good thing if its pulling enough anyways... dont be so concerned about getting it at optimal. If its doing what you need it to do then just leave it and youll find you will automatically go in a click or 2 at some point.
You can get caught up in trying for optimal but something to remember is that you will need a number of tanks to get it singing. People that say they can get an engine singing in a tank are talking rubbish (unless they know that particular engine).
Obviously the good thing is with a pumped OS is it will pull no matter what

[michael_fly_more]

Guys?
are we getting a little confused here? As reading through out of all my
55HZ-R 91HZ-R. 91HZ-R. 91HZ-R speed 105HZ-R all regulated and I've had many and mean many of each of these

ive never had a mid need over 1 turn norm under 3/4 even the old 91SZ regulated was way under 1 turn

this is on 30% nitro and on less nitro the needle settings would be less

so my point is I think some people are quoting non regulated needle settings as well???
even the is manual quotes to run in 1 turn for regulated engines

the post was started asking for HZ-R regulated settings

please note I'm not a fending anyone just trying to get my head around 1 1/2 turns on the mid settings that has been quoted?
as above no 2 engines are the same I've had same engine same pipe same fuel same filters same airframe same head spoofs same blades etc
I fact a nearly exact copy and the needle settings are different so I get that just never seen a regulated mid setting over 1 turn

i say mind if you was flying on a mountain and extreme heat the needle setting would change a lot

thanks for reading guys

M

[Planehazza]

Guys?
are we getting a little confused here? As reading through out of all my
55HZ-R 91HZ-R. 91HZ-R. 91HZ-R speed 105HZ-R all regulated and I've had many and mean many of each of these

ive never had a mid need over 1 turn norm under 3/4 even the old 91SZ regulated was way under 1 turn

this is on 30% nitro and on less nitro the needle settings would be less

so my point is I think some people are quoting non regulated needle settings as well???
even the is manual quotes to run in 1 turn for regulated engines

the post was started asking for HZ-R regulated settings

please note I'm not a fending anyone just trying to get my head around 1 1/2 turns on the mid settings that has been quoted?
as above no 2 engines are the same I've had same engine same pipe same fuel same filters same airframe same head spoofs same blades etc
I fact a nearly exact copy and the needle settings are different so I get that just never seen a regulated mid setting over 1 turn

i say mind if you was flying on a mountain and extreme heat the needle setting would change a lot

thanks for reading guys

M

Yeah that's it. Those with 2+ turns must be running non regulated OS105HZ. The regulated HZ-R is almost like fuel injection so will be inherently richer than non reg. Your settings are coherent with other with HZ-R motors. Mine was seriously smokey and sound 'splurgy' so I think it was overly rich, especially with it being very hot and humid last night.

I'll crank them both to one turn and go from there...

[michael_fly_more]

Harry

what ever you do if this is new or under one gallon old what ever you do don't set the high needle to one turn
you need to take time spec as it hot out run main least between 1 3/4 and 2 turns out and mid at one and don't load engine just gentle flying with not much pitch and not to high head speed either

dont touch the mid yet even once it's had a few tanks
after about 6 tanks running rich then slowly start to lean the high
dont touch the mid till you have the high sorted

the main thing to watch for is heat this is so so important as too hot it will kill the engine
but I'll need slight heat to run it in

its a bit of cat and mouse but don't rush things no matter what

too rich won't really hurt
too lean the engine will be toast and your then need new engine or least piston ring and liner


TAKE YOUR TIME