GO24GO

Mike, where can I find a pre-made double servo arm? I've searched Tower and this site, can't find any. I read about it in your review of the SP SU31 3D. I'm an ok modeler, but have never done a pull pull linkage before. Too much $ in this for me to screw it up. So, I am a candidate for going the pre-made route. Thx.

nitro wing

My Feedback: (1)

Run the pump,at first I had alot of questions too.I read so many posts it made my head spin.For some reason some 160s ran OK without pump,but many suffered lean issues,when using Slimline or Bisson mufflers.The pumped 160 rarely ever needs any adjustments,its just a reliable powerhouse,no hickups.

Rocketman_

The "mounting hardware" is just a plastic clamp which is held to the fire wall with one screw. You provide the screw. The pump fits loosely in the clamp and you may have to wrap a couple of layers of tape around the pump to snug it up. You provide the tape.

Drilling and tapping the crankcase REAR COVER is easy but if you're a little sloppy at tapping thin walled aluminum for tiny fittings then the fitting may not stay in. You can probably glue it in with J-B Weld.

I use the more substantial O.S. 140EFI fitting that can be screwed into the existing upper left bolt hole in the crank case rear. The fitting replaces the crankcase cover screw that is intended for that hole. Then, using the fitting as a drill guide, a hole must be drilled into the crankcase. Needless to say, you must prevent any metal chips from falling inside the engine.

The O.S. 1.60FX is a very "user-friendly" engine and you will be impressed by it's easy starting and with it's power, reliability, moderate fuel consumption and short break-in period. If you have troubles with it you may find that you're doing something wrong.

You can see the Perry pump and O.S. 140EFI fitting at Tower Hobbies http://www3.towerhobbies.com/cgi-bin...&I=LXDG59&P=SM

The pictures below show the pump's mounting clamp and a homemade pressure tap that I made for my first O.S. 1.60FX.

GO24GO

Rocketman. Many thanks - pics and all. You got a chuckle out of me... "you provide the tape." I can manage that! I don't have the engine yet (ordered). So, if I understand correctly, I can drill clear through that upper left bolt hole and that penetrates the crankcase? How does one keep metal shavings out? Anytime you drill through something the penetration carries forward a degree of material. My 1st thought was to somehow do the drilling with the engine inverted (thus gravity helps?). I would also go very slowly and encourage the bit to "hold onto" the shavings. I just don't want to ruin a brand new engine. Is there a trick?

maineflyer

My Feedback: (44)

When I tap the backplate. I take the plate completly off and drill it and then tap it for the threads on the fitting that comes with the pump. For the screw hole I would take the backplate off again and try to isolate that area somehow. I would be interested Rocket as to how you do this. I like the idea of going through the mounting hole. I have a new 1.60 going onto a Ultra RC Katana and want to put a pump on it and was thinking about trying the 1.40 fitting.
Jeff

Rocketman_

Maineflyer is, of course, absolutely right about the backplate having to be removed to do the drilling no matter which pressure fitting you choose to use. Some people disassemble the engine before they drill the crankcase to make sure they can thoroughly clean it after the drilling.

With my first OS 1.60 I was in such a hurry to fly that I couldn't wait for the O.S. 1.40 fitting to arrive so I made my own fitting and I was certainly not inclined to spend time disassembling the engine. I removed the back plate and stuffed the crankcase with oily paper towels (Bounty) before drilling and carefully removed the stuffing afterwards. I used a magnifying glass and an oily Q-Tip to remove the very few tiny particles that remained. I didn't worry about it much because model engines can digest soft metal particles and survive. Anyway, I've drilled three OS 1.60's using that method and none of them have shown any ill effects.

FLYMIKE

On the OS160 I thought there was a hole already under one of the screws...cant remember which one though.....

Rocketman_

FLYMIKE
Have you actually seen a hole under one of the crankcase cover screws? Apparently no one who has ever disassembled an O.S. !.60 or removed the cover has ever found one.
The reason you drill through the upper left screw hole is because it breaks through into the crankcase cavity at the fuel/air by-pass. The other screw holes lead nowhere.

It would be a nice consideration if O.S. drilled that hole during the manufacturing process.

nitro wing

My Feedback: (1)

Thats what I found,when I took the cover off,no thru passage,wondered what people were talking about.I tapped the cover,put a touch of JB weld on the threaded fitting and no probs in 2 years.

JoeAirPort

My Feedback: (41)

Wow, seeing this statement from a moderator is very surprising. Is this based on first hand experience Mike? I had both a Moki 1.80 and a 2.10 and ran them on Omega 0% nitro for two years. I used to post all the time how fuel efficient they were. If you use 0% nitro and know how to tune them, they use very little fuel for their size and power. Also I used a Cline regulator which further increased the fuel economy. No they were not glow guzzlers at all. You just need to know how to set them up and tune them. Anybody that needs help with this please PM me.

nitro wing

My Feedback: (1)

People say the same on the 160.I have the stock tank that came with the EF Yak.I fly mixed 3D for 10 -12 minutes and land.
There is a 1/2 tank remaining of 10% glow.
But I flew it just a bit too rich when I changed fuel brands,smoke and some sputtering,but cleared out for lots of power.
After 10 minutes,I land and wow,the tank was almost empty!! I retune, 2 clicks,leaner but still good smoke trail.
Fly 10 minutes and check fuel,1/2 tank remaining.
So its important to get the needle right,the motor ran well on both adjustments,but consumed much much more on the rich side.
If I burn 15 bucks worth of fuel on a Saturday of flat out fun,its not a big deal,yeah a gasser will probably do all that on less than 5 bucks.
At my field many guys run rich,especially the 4 strokers,flat out they are at 6 or 7K,and then they wonder why they use so much fuel.
I run an OS 120 4stroke to the max with 30%.But never ever do I let it go on a lean run past 8-10 seconds.Good settings and throttle management are key to power and economy.
This is in no way directed at MikeEast in any way.He can tune I am sure.
Just a general response to some peoples believe that big nitros are pigs

Rocketman_

That is good advice gained from experience.
It appears that many people believe that "gods" at the engine factory set the needle valves and you dare not screw around with them too much.

asmund

Do they even get in the air with the engine so rich it will not go past 6-7K at wot[sm=bananahead.gif]

nitro wing

My Feedback: (1)

sure,a lighter 91 powered will fly pretty good at 7k,some of the guys are too conservative and/or fly a Cub or similar wich does not require full rpm.But some complain that they have no performance,and often its because they are slobbering rich and run garbage propellors.
I do run my motors lean,but I also take care of the duration I subject them to.
In the 20years and 12 nitro motors ,I have never had a single engine failure except for 2 glowplugs.
All engines were OS and one magnum .46 which I tried to unsuccesfully burn out or granade.
Maybe I am just lucky

asmund

I`m quite lucky too, I run all my engines just a hint rich from peak power, never had a problem in 5-6 years now

MikeEast

My Feedback: (3)

Being a moderator has absolutely NOTHING to do with that comment. We are just fellow hobbyists, we dont get paid. Moderators are no different than anyone else who post in the forums, except we help to make sure that everyone abides by the forum rules and post in good spirit. We typically try to hold ourselves to a high standard and post productively, but that does not mean that we are not entitled to have an opinion. And,,,, stating the obvious we should be abiding by the rules ourselves. There is nothing in the rules that says I should not say that I think the Moki 1.80 uses a lot of fuel basis my opinion. Whether my opinion is founded or unfounded is really irrelevant, its just my opinion. Personally I think when you get the the point that you NEED a 1.80 you might as well go gas, they are just not cost effective. Thats also my opinion.

nitro wing

My Feedback: (1)

I agree,the 160 is as big as I need to go with a glow engine.
40-50cc gasoline engines have become quite available,and even some knockoffs are not bad engines,and they have become equally affordable,sometimes costing less per cc than a glow.

Gus155

they both great engines.

Uncas

My Feedback: (1)

These are all interesting comments. When I was evaluating engines for my GP YAK, especially the Moki 2.10, the weight difference between that and my B46 gas engine did not seem that great. I think probably that the power, cost and weght is so close that it is more a preference of the pilot. However, I have decided to use the OS 1.60 simply for the weight savings and judging from some of the other posts here I shouldn't be disappointed.

GO24GO

Big S,

The OS 1.60 fits EASILY in the GP SU31. I'm just finishing mine up. I have had multiple people tell me the OS 1.60 is plenty for this plane. Our forecast is for pretty good weather Mon or Tues this week, I hope to have a flight or 2 under my belt by then.

Here's my question...

I am really struggling getting my OS 1.60 to start. I took it to my LHS and they were VERY HELPFUL - Slot and Wing Hobbies in Champaign, IL. Anyway, they finally got the engine to run (after about ONE HOUR). It was pretty clear to the guy that helped me that the engine was getting too much fuel. I have a Perry pump on it and we think that was the the culprit. The manual called for 2 1/2 turns on the needle valve from closed. We finally got it started at 1 1/2 turns on the needle valve. Fuel was dripping out of the muffler exhaust and at one point we were pretty sure the engine was flooded - after only minimal priming. Has anyone else had this issue? Is the Perry pump really putting that much fuel in there? 1 1/2 turns, 1 turn on the needle valve? How much to prime? What's the best setting for getting it going? I really hope the engine isn't this finicky all of the time. The OS 1.60 is so common, I'm hoping people might have experiences to share.

Thx,

nitro wing

My Feedback: (1)

All my manuals are buried somewhere,but basically if the engine runs fine with less turns out thats OK and probably normal as the pump is pushing fuel in...
When it is running,just make sure that you get wide open throttle and rpm,then you know the pump is delivering as much as needed.
Do you have a manual for the pump?
If you can get full sustainable rpm,just tune the engine as normal and go fly.It should idle 100% reliable and have good transition.
Mine was a bit rough on the cruising midrange stage,but I waited until I had about 1 galon thru it and then tweaked the low end just a touch,and it went away with break in time.The motor has never quit,even during "almost break my plane" manouvers.
The only time I had a deadstick ,is when the line came off the pump.The heavy APC 18x6W is a good aerobatic/3D prop and gives it some flywheel effect.Good thrust and top speed,but it depends on airframe.The clamp does not provide adequate hold.I wrapped a bit of hockey tape around the pump and it aint moving.