Harry Lagman

Good test info Summerwind - thanks.

FlymoreRC

Hi,
I'm new to this tread.

I'm thinking about the FS81-a as a replacement for an OS FS70II. The marketing material says it'll fit where the OS70 came from. My concern is the exhaust port. I'm using a non-standard exhaust (ie, a Keleo-enterprise OS 70 Pitts). Is the threading x size, and port angle the same for the FS81 and FS70? I can't seem to find any documentation anywhere and my nearest hobby shop is miles away.

Thanks for any replies...

Michael

TimC

Michael, according to the O.S. parts list for this engine at their web site, the exhaust is the same.
OSMG2687 72108120 O.S. Flex Pipe 1111C 70/91 Surpass This is given as the flex pipe for the .81.
Here's a link to the page at O.S. Engines: [link=http://www.gpdealera.com/cgi-bin/wgaprt100p.pgm?I=OSMG0981].81[/link]

FlymoreRC

Just an update on comparing the dimensions of the OS FS70II compared to the FS81-a.
Web site: http://www.os-engines.co.jp/english/...81_e/index.htm has the dimensions of the fs81-a. Comparing the FS70 with the FS81, they are nearly identical in external size and mounting. The new carb is a bit more compact than the FS70. Even the exhaust port is in the same position and angle which makes the FS81-a a good swap out for the FS70.

Personnally, I would not buy the FS81-a for a new plane, or a major rebuild of an existing plane. But for me, I have a very nicely scaled out Sig 1/5 Cub and could use the extra power. I can rationalize the higher cost of the FS81-a by the offset of not having to redo my cowl or custom exhaust (kelo-creations).

kochj

Year later....
FUnny how times change@@....
Saito, Ys, Magnum..........ALL RAISED THERE PRICES....
Guess you all have to ***** and moan some more....

THen you all have to look at the up and comming rights to produce planes...yes thats right....
Pythons, THe BEAST, ect... will have ROYALTIES.....
THen there are the CAPS, EXTRA, CUBS, CESNA's....

Open you Pocket books....

Ernie Misner

Hey kochi, do you have a link to any info on the royalities that will have to be paid out?

Thanks,

Ernie

kochj

I was mearly a thought of recent events Superimposed of the past relations that have been given much leaway.....

Horizon's recent aquizition of QQ Aircraft Comp. brought with it the previous partnership of K. Kimball and the recent announcement of "The Best"
When you purchase this plane, you are paying for the royalties.... Buy the GP Cessna twin ( you are paying the royalties)
Matt chapman 580 2nd gen.....You are paying the Royalites....
Other manufactures are not actively persuing there given right to colect on there dues.....Give them a call, I am sure
they will direct you to there Consumer relations, who would be happy to ask you which model aircrafts you own, your address, and
how many of them....
Here you go....

http://www.yak.ru/

http://www.cessna.com/

http://www.extraaircraft.com/about.asp

http://www.zivko.com/edge/index_edge.html

http://www.jimkimballenterprises.com/web/custom.php

Pippin

...just some comments on the O.S. price. In Japan, the 81 Alpha costs around 200Euros in the shops. It is therefor cheaper than Saito and YS. I think, O.S. are only overpriced in the US and Europe because of some importers like to ask for our money without getting a flush. Anyway.

I want to buy an Alpha too but the question is rather which one. Should I get the 81 or 72. There are more or less designed for the same class of models (according to the O.S. catalogue 2009). I want to put the engine into a Kyosho Calmato Sports 40 and or a scratch built 66inch warbird as well as a Marutaka Hayabusa. The price difference is not an issue.

Are there any info out there about fuel consumption, since tank size is restricted.

estradajae

actually the prices for the 72 and 81 are the same?

I would go for the bigger... i think is the same size, or almost the same, and almost same weight...and no price difference...

I hope Graupner now sells them with the muffler...not like before with the surpass...without muffler.....

Saludos,

Jorge

kochj

THe os engines didn't have mufflers in you country??

estradajae

Graupner, the exclusive importer of the O.S engines here, used to remove the mufflers from the boxes and they sold them as an accessory (both 2 and 4 strokes), and very high prices though up to about 60EU each, with the new alpha and AX seems that they are selling the engines with mufflers...

Something similar happens with the radios, Robbe is the exclusive importer of Futaba here, and they sell for example the 6EX 2.4 Ghz at about 200EU WITHOUT servos and batteries...just the Tx and Rx. I bought my the same radio at Tower a couple of years ago and it was 230 USD and it came with 4 BB servos and everything..as usual.

Pippin

...I got the 56Alpha for some 165Euros, muffler included. I had all Alphas on the desk. Since I already had bought a TT75S rated at 1,2HP before and some chat with the shop assistance I went out with the 56a. Sweet engine. I think, my next Alpha will be the 110. Actually, I wanted to buy this one too but I thought the custom service at the airport would make some trouble seeing all these engines in my bag. Anyway.

Broken Wings

My Feedback: (20)

How does everyone "who owns" a OS FS-81a like the engine?

How about an update.

mike109

G'day

Thanks for reminding me that I own one. It is in a Hanger 9 Piper Pawnee. Here in Oz the recommended retail price is nearly AU$500 but the street price is about AU$389 which is AU$ 40 more than a Saito 82.

So how do I like it? It runs fine but is not $40 better than my Saito 82. I only paid AU$350 as the local store had several in stock and decided to have a sale which made the price almost reasonable.

I ran it in as I would my Saitos, I use the same fuel and the same size prop as the Saito 82. Performance is still a bit sluggish as it is not fully run in yet but it was reliable and the idle was just about right out of the box (a little rich).

Would I rush out and buy some more Alpha series engines? Probably not. They are too expensive and the fact that you can't easily lubricate them via the vent (because they don't have one) is a bit of a worry. I also worry that the internal plumbing may gum up.

And so ... My next engine is going to be an Enya 53TN direct from Ken in Japan. I could buy another Saito but I just like something different every now and then. Or perhaps a Laser 80?

pilotpete2

I missed this thread and started a new one regarding this engine[:-]
http://www.rcuniverse.com/forum/m_10026259/tm.htm
Pete

slembones

My Feedback: (1)

I have all the alphas and they rule!. ys has more power but alphas are smooooth as silk. purr when they idle and sip fuel. the 81 runs an APC 14 x 6 @ 9700 peak. the sound is very scale and lots of muffler attachments for different mounting angles (inverted and such.) one caveat, you must oil the helk out of them at the end of the day or the bearings WILL rust. best method to oil is?
Use your oil of choice and put in 20 drops at air intake, spin prop, repeat 5 times. I use MMO... Love'um

Slembones

twin3d

I have two of these on a Top Flight B-25 and I am having the same problem. They both gummed up and had to be torn down to clean and oil them up. Unfortunately I have no way of getting into them to oil them as they are in a cowling. I have always been a fan of OS engines, but not these anymore. To expensive to have to worry about oiling them every flight. I plan on repalcing them with the new 10cc gas engines from Horizon.

asmund

If I needed an .80 ish sized fourstroke I`d just get the proven Saito .82 and be done with it, lighter too Actually I`m looking for one in the auctions[8D]

Edit due to bad spelling

CNXRC

I need to replace the bearings in my OS 81FS-a and have stripped the engine down entirely until I get to removing the piston. Does anyone know how to remove the piston pin to get the con-rod and piston out? Usually the is a hole to the back go the cylinder head for it to pass through but not so with this engine. Any help/thoughts would be appreciated.

Bax

My Feedback: (11)

Normally, you slide the liner up and out, move the piston as far aft as possible and then move the connecting rod as far aft as possible on the wrist pin. You can then work the lower end of the connecting rod off of the crankshaft. Sometimes, it needs a little help to pry it off. The head of a carriage bolt can do this.