OS 105 hzr servicing / life span

[chrisleematt21]

I've just ordered a new os105 as the last one was second hand and has got several issues so thought its best to start with a new engine.


How often should i be stripping it down and replacing the bearing / giving it a once over?

I run optifuel 25% and fly at 1950 ish hs.

[Stuart]

I suspect there will two schools of thought. Firstly every year/season if your a regular any weather flyer. Secondly like me due to family and weather its when I get a chance too so I tend to take the back plate off and check for rust and turn over the engine by hand and feel for knotchy or anything other than silky smooth in the bearings. If the compression is low then replace the ring on the piston. Any scoring in the liner replace that also.

[Stuart]

My 105 must be 5yrs old by now and on its second set of bearings and ring...

[chrisleematt21]

Crikey that sounds pretty good

But do you fly it

[milly0812]

It also depends on how you look after it. Mine have lasted much longer since I followed Rob (rctintin) shut down procedure.
at end of flying obviously burn off any unspent fuel and clamp the lines,
replace muffler bung and close the carb via throttle servo.
then turn the engine by hand until the piston is at the top.

[waveydavey]

Don's method above except the burning the fuel off. Haven't had any of the issues I seemed to have earlier in the hobby. You'll hear the rear bearing, the death rattle we call it, replace with new and don't worry about the front.

[TonyM]

Just a little something to add to the above,
I too was having to replace an OS rear bearing every 8 months to a year even when burning off excess fuel etc.
What was killing mine was where the heli was kept, in the garage, the temp fall etc sped up the rusting process.
I now keep them in my office in the house and not changed a bearing yet on my 91's (still following of course the end of flying protocol/storage)

[paul 5ive-t]

my 105 has done nearly 5 gallon before i totalled the hei! I built it last November, I ran 25% optifuel at 2000 headspeed, on stripping I decided to check the bearings...rear was shot, I fly in anything but rain and carry out the same end of flight procedure as said above, I think as (stuart) says if you fly cold and damp (all weather) you will probably have to replace more often...I would say flying all weathers makes you a better pilot but that didn't do me any good!!

[paul 5ive-t]

oh yes..all heli's are kept within the house so damp not an issue.

[waveydavey]

Garage, damp and draughty

[Mike Sanders]

I don't know much about the OS engine but I do have some experience of two stroke (and four stroke) engines.

I think that if there is some oil in it and the carb inlet and the exhaust are sealed (even with just an oily rag) there should be no deterioration even in extreme external conditions.

[TomCarey]

I have mixed experiences with the 105 from new, 8month to a year Hassel free

My newer one of the two, a known fault the piston ring retaining pin wore out and caused complete destruction..
my second engine has just done the same thing.. ripmax have an excellent aftersales care with this engine.

One was completely rebuilt foc by peter hallman @ ripmax and my second one is currently with him.

[acidla]

I have mixed experiences with the 105 from new, 8month to a year Hassel free

My newer one of the two, a known fault the piston ring retaining pin wore out and caused complete destruction..
my second engine has just done the same thing.. ripmax have an excellent aftersales care with this engine.

One was completely rebuilt foc by peter hallman @ ripmax and my second one is currently with him.

If need be, how we can get in contact with him?

[waveydavey]

Go through Ripmax and add Pete's name for the attention of. He's well aware of the issue and OS have released a solid square pinned version of the above rather than the C Lock type which is rubbish. You can read my findings in various OS105 posts on here but I firmly believe it's down to side play on the con-rod. Petes email is in post 9 on the second thread

http://www.rcheliaddict.co.uk/engine...ation-pin.html

http://www.rcheliaddict.co.uk/engine...-ring-pin.html

[acidla]

Awesome mate