OS 1.60 question
 

I just got an OS 1.60 FX and was wondering what the fuel nipple is for on the back plate? I was told it may be a crank case vent. What is it's true purpose?

RE: OS 1.60 question
 

They were probably running a Perry pump or a regulator. The crankcase pressure drives the pump diaphragm in a pump set-up. In a regulator set up, the crankcase pressure, pressurizes the fuel tank.

RE: OS 1.60 question
 

So do I just need to plug it up? The engine is slightly used and after all the posts I read, I have the same problems as a lot of 160 owners. If I run it rich on the ground at full throttle It will just die as if the glow plug burned out. But it will re-start every time. I re-located the exhaust nipple to the top of the pitts muffler near the head and will see if this fixes the proplem.

RE: OS 1.60 question
 

What muffler are you using ,if its a bisson I can say this for sure you will need to either use a pump, regulator or mash one of the tubes closed .But remember in closing off the tube some of your power will go away with it .
What I have done is to make press on caps that go over the tubes with smaller holes in them .That allowed for good tank pressure and still have peak PRM's .

RE: OS 1.60 question
 

Yes its a bisson. I have it on a Direct Connection Ultimate, which AUW is 12 pounds. I really don't want to close off a tube. I will run it with the exhuast pressure line moved to the new position and see how that works. I only had one dead stick so far, but that was enough for me. It almost cost me a plane.

RE: OS 1.60 question
 

Let us know if you find the magic spot for the pressure fitting so far I have not been able to .

RE: OS 1.60 question
 

I have a carl goldberg yak 54 and extra 330 with a 1.60 still in the brake in stage. I have 18+10 props on them thay preform good but i think thay are small for the planes.
i was thinking of putting a 20+6 on one . is this a bad idea?

RE: OS 1.60 question
 

Acam37,
You need a pump, even closing off a tube is not enough.

cyberwolf,
The top left backplate screw is tapped for a pressure fitting, when looking from the back.

RE: OS 1.60 question
 

HUH ???? I'm afraid that one has lost me .I was talking muffler pressure as was ACAM 37 not crankcase pressure. But thanks anyway.

RE: OS 1.60 question
 

cyberwolf,
Sorry about that, I misunderstood your post

RE: OS 1.60 question
 

I had a 160 which I recently sold to a friend. It ran just fine with a Bisson Custom Muffler. No tube crimp or anything. I did eventually install a Perry pump so that I could move the tank back to the C.G. It ran great witht he pump also. If you want to try it without the pump, just put a short piece of fuel tube on the pressure nipple and plug the end witrh a screw. If you have trouble getting it to run properly (as some seem to) then you can go for a pump. I think the trick though is to not 'over-lean' it trying to get every last rpm out of it. Just set the low speed for good transition, and set the high speed so that you can see a tiny bit of a smoke trail as you fly. I got that info from this forum and it worked for me.

RE: OS 1.60 question
 

I totally agree with you there ,thats what I did with mine and it seems to run fine .Now my 2300 ST is a different story all together, but I think I now have it where it will run fine W.O.pumps or regs.I suppose in the air is the big proof.

RE: OS 1.60 question
 

This simply is NOT true... I've seen guys say this many times... and SOMETIMES it may contribute to the problem... but I just finished the GP CAP232 review with a 1.60 and Bisson muffler. Built stock with a tank position most were cringing at.

You do NOT necessarily need to crimp the exhaust tube or use a pump/regulator.

Side mounted on the CAP the engine ran beautifully on 10% nitro.... no fussing at all, no leaning or running too rich. Started with one or two revolutions of the starter.

Like a top.

Many are making things worse by using larger fuel line which DECREASES pressure as what pressure there is has to push MORE fuel through the line. Just use the medium fuel tubing and no filters...

Keep the fuel line/pressure line as short as possible, use fuel barbs so no air leaking, and start with lower Nitro fuel on new engines...

THEN if you still have issues, look into the "fixes".

RE: OS 1.60 question
 

Well goody for you ,I don't run either on my set up either, but thats one in several that do .So dont be calling me a liar that does not set to well.
I did not say anything about larger tubeing ,you did !
And I dont care what size tube you use on the muffler side once the pressure has been established it will remain the same to a degree but will change some as the tank goes empty .
If you don't beileve it get yourself a manometer and check it yourself.

RE: OS 1.60 question
 

my 1.60 seems to run great with no pump and a slimline muf . can some one help me with my prop . what prop is everyone running and is 20+6 to big ?
i am thinking i should be safe if i use a wood one.

RE: OS 1.60 question
 

First off thin skin,

I wasn't responding to you... a poster stated "You need a pump, even closing off a tube is not enough. "

The original poster hasn't even run this engine and isn't compaining of problems. To say all 1.60's in all setup MUST use a pump/reg is ridiculous.

It simply is NOT true.

And you go right on beliving your pressure theory... when you get a chance to study basic principles and theory of plumbing... maybe you'll reconsider your position.

Til then you go right on ahead jumping people's case... it becomes you.

-J. David

RE: OS 1.60 question
 

Kempo,

It really is more about your flying style and preferences. Are you looking for 3D, IMAC, sport flying? Pattern or fat wing funfly?

One of the most popular 3D props is an 18x6W... for good spool and low pitch speed. IMAC and pattern guys might like less diameter and more pitch maybe a 17x8 or 17x10...

I enjoy the slower, high alpha stuff... and like the 18x6W myself... truth is... until you try a few different props on your specific airframe, you'll never know what YOUR best prop is. While they aren't cheap... you might try a couple or even 3 sizes/varieties of props...

I've heard the Skorpia from http://www.escomposites.com are really nice, lightweight props... with good spool... I'm looking to try a few myself soon.

RE: OS 1.60 question
 

First off your the one that circled my post in relationship to your post ,so don't try to hide the fact,as far as being thin skinned ,not really, unlike most if I am wrong I can admit it but don't call me a liar doing so. Like I said I don't use anything and get away with it, but most don't .I wish I could answer the WHY question ,same type of set up ,but some just won't put enough tank pressure to stay running WO the use of a pump or reg,or crimping off one of the tubes .I have see a couple that has no top end needle adjustment what so ever .you can screw it all but out of the carb WO any change
Now for the other deal ok say you have a air compressor ,it has a 1/2 inch line feeding the air tank ,you decide that you want to add a 1 inch line ,thinking the larger line will allow more air and a faster fill rate . When you double the line size you make 4 times the area of flow .
That being said when the pressure starts to build, the compressor will still only put out so much at a time when it equalizes the pressure in the air tank the fill rate will remain the same .

The same thing will happen to a fuel tank on a plane .Believe me I have played that game ,going from very small to very large without any different results .And as I said before hook it up to a gage and check it .

Now if your talking the feed line to the carb then yes I will agree with you ,the larger tubing takes more pressure to get the same fuel flow and is not a good idea .So far I have never had the need to use large tubing on anything ,and I have been at this for well over 40 yrs and learn something new with each project .
Sorry we got off on the wrong foot here .I think the main reason for this site is to try to help fellow fliers not to fight among our selfs or try to shove our beliefs down another throats .

Oh BTW way PLumbers School Hots on the left and water runs downhill ,next student !*LOL*

RE: OS 1.60 question
 

CW...

As I said nobody called you a liar... I said that a BLANKET statement was not true... and even if you HAD made that statement, it would have meant you were wrong... not a liar. Two were made... one was he HAD to use a pump and the other was that if it was a Bisson it HAD to be pinched. My own experience has not shown this to be an absolute.

Not sure what's got your panties in a bind here... but take a breather, and understand that if you TOOK it I was implying you were dishonest... well I certainly apologize... but that was not my intent... textual messages can sometimes get misinterpreted... which obviously is the case here.

I probably don't know very much about anything... but the thing I do keep an eye out for is information that newcomers might assume as absolute gospel. There is probably as much misinterpreted information as as anything on the internet... and there's no reason why we can't all work together for clarity.

I don't think anyone else reading my post will take any position other than I strongly disagree that you HAVE to use a pump or reg to get an O.S. 1.60 to run great. I think I made it abundantly clear that it's more of an issue with the particular installation than the engine itself.

Some may very well have the need to resort to a pump or reg in their installation. But the original poster's application may not require one at all. Someone told him he HAD to use a pump or reg.... And I'd hate to see him go spend $50 on something he may very well not need.... then again he might.

Anywho... again, my most humble of apologies if you felt I was callign you a liar. That's a pretty strong word... and I sure didn't use it anywhere.

Have a goon'n.

RE: OS 1.60 question
 

I also relaize that I only quoted one person and that happened to be yours... I've edited the post so I dodn't quote anyone specific. Again... didn't mean to single you out...

I agree with you that not all installations require a pump or reg.... and am somewhat baffled as to why that is... but it is...

RE: OS 1.60 question
 

Hay Maudib thanks for your reply . but i guess what im getting at is its a big prop and out of rang of specs for the motor. can it haert the motor like over heat or over work it? has anyone tryed a 20+6?
and how well did it preform ? this air frame is the carl goldberg yak 54 with the 1.60 i dont have a good scale but its between 13 and 14 lb.
and im looking to 3d this bad boy . CAN IT BE DONE?

RE: OS 1.60 question
 

Just wanted to give you all an update on this engine. First, I changed the pressure nipple.(You can see where I moved it to in the picture). Took it out to the field, took off, and about 6 minuets into the flight; you guessed it, engine quit. After 5 more flights, 5 more dead sticks. The problem continues. All of everyones combined knowelege at our club cannot solve this one. I even bought a new tank and fuel line so I know that is not the problem. One thing that we are sure of, it is almost certainly a fuel delivery problem. After every landing you can see there is no fuel in the line all the way below the needle valve. So the next course of action is to get a pump and try it.

What we believe is happening is that when the tank is full there is less volume to pressurize. So the engine runs fine. Then as the tank empties it gets harder and harder to keep pressure in the tank, until at a certain point the tank loses pressure altogether and starves the engine of fuel. It seems that the engine quits at just a little above half a tank.

RE: OS 1.60 question
 

Looking at the pic... the tank looks like it is probably a decent amount lower than than the carb.

When the tank is full, it is effectively drawing fuel from the top of the tank (even though the clunk is at the bottom) that is nearer the carb level. As the fuel level drops, the pressure must push the fuel harder to reach to carb.

It's possible that the engine is leaning out too much at this point and overheating... You might try a adjusting both the low and high needle a little richer.

A good test would be to fill the tank only 1/3 full... and set the needles including several "nose high" tests. If it is indeed pressure... then you should not be ale to start and run the engine ont he ground with 1/3 tank. Or at least certainly see the iue when holding the plane hose up.


Another possibility worth looking into would be to run a header tank if the airframe allows... a small 2 oz tank mounted ner the top of the turtledeck near the firewall. This creates a "buffer" of fuel as the header tank is always completely full. It doesn't provide better pressure, but rather a staging point to possibly keep the engine from going lean. May not help at all, but maybe worth the $4 approach over a reg/pump.

RE: OS 1.60 question
 

Let me ask you this ,how is the needle adjustment .That is the first clue if your having a presure issue .
And I also noticed your tank if much lower than the center line of the carb as Maudib did .I have never ran a header tank but have seen a few that have with good results .Usually the problem is enough room to get it all in the plane .
I would do as Maudib suggested and retune the engine with 1/3 of a tank and see if that helps your problem out,by doing so it may create a rich condition for the first half of the tank which may or may not not be flyable .
Good Luck let us know what you come up with .

RE: OS 1.60 question
 

I know this sounds dumb, but it seems the richer I tune the engine the sooner it dies. When I lean it out as much as I can I get longer run time. I will try the 1/3 tank test and post the results. The tank is as high as I can get it. I will also post a pic of my tank setup. If I do need a pump then that is what I will do.