brian402

I'm having trouble with my Enya 80 4C. Can some of you more knowledgeable engine gurus help me out??

The engine is extremely sensitive to pitch change. Even if I richen the mixture until it's spitting raw fuel out the exhaust, it will quit if I change the pitch of the model's nose abruptly. The fuel tank's stopper is new and the clunk is free.

What is the correct way to plumb the engine? There's a tap off the case and off the exhaust system. I have read that the case tap is just a vent and that the tank needs no pressure... Is this true??

The carburetor seems to be seeping right around where the throttle arm connects to the barrel and it's spitting fuel out of throat at any mixture setting. Carburetor problem??

Any help is much appreciated!

P.S. The engine went in for service (complete rebuild if I remember right...) at the factory about four years ago and hasn't been run until now.

Thank you,
Brian.

seanychen

My Feedback: (4)

Hello,

Before flooding you with my speculations, I want to say that I am assuming this is the Enya 80 4-stroke w/ air-bleed carb, and its muffler is a straight manifold without pressure tap, as shown in the attached image.

If this accurately describes your engine, then I think the leaning due to attitude change is that you don't have enough pressurization to drive the fuel from tank to carb when the tank is shifted lower due to attitude change. The crankcase pressure is not to be used to pressurize fuel tank, because 4-strokes crankcase breathe in and out throughout the its cycle. This one should be left along; maybe you want to put an open-ended fuel tube on it to route its spit away from firewall. As far as pressurizing your fuel tank, the lack of muffler pressurization may explain your problem.

One remedy for this sympton is to add a Perry Oscillating pump between the tank and carb, which uses the engine vibration to draw fuel. But before you buy anything, try to see if your engine will run acceptably (slightly rich) at full throttle when you hold the plane vertically. If the carb is capable of drawing adequate fuel (no matter how much you open the high speed needle) when fuel tank is verticaly below it, then you don't have a leak problem

As far as fuel spit between barrel and throttle arm, I suspect it's due to your rich idle. My Enya R1.55 spits duing its rich idle too. Fuel leak path is not at the throttle arm screw hole: the screw hole is not connected to the air-fuel source in any way; but rather between barrel and carb housing. But it doesn't hurt to check if there's a leak.

Good luck!

Phil Heller

My Feedback: (9)

Brian,

I have been running Enya 4strokers, (80, 90, 120R, 155R) for about twenty years and my 80 4st. is the most user friendly, sweetest running of the bunch! You should not have to use any form of pump or pressure as the smaller diameter throttle throat has more than enough draw. Carb spitting is because too much fuel is ingested in the carb before the port closes. I would look for an air leak at the carb, either where it attaches to the intake manifold or around the needle valve. I assume the valves are set correctly, and the tank is neither too high or too low. Fuel that has been contaminated with water vapor can also be a problem.

Phil http://www.quiknet.com/~pheller

jaka

Hi!
Do you use.....
......a 6-8oz tank ,with tankcenter at the fuel inlet orifice when airplane is horizontal?
....an OS F glowplug?
....fresh fuel that contains 5%-15% nitro?
....a 13x6-15x4 APC prop....balanced?


Regards!
Jan K
Sweden

brian402

Thanks for all the replies.

Yesterday I finally had the chance to read some of your suggestions. I now have the crankcase breather tap dumping overboard (spitting raw fuel on the belly) and the tap from the exhaust pressurizing the tank. The exhaust is a "Y" design that does have a pressure tap on one of the outlets. Perhaps this isn't enough pressure to the tank?

If I richen the high end I can get the engine to run in a nose up attitude. It spits and sputters while level but when I raise the nose to vertical it leans out and runs well. However, as soon as I make an abrupt nose down change the engine will quit. I have tried the OS type F plug as well as the Enya #3 with no difference. I am using a 15% glow fuel, a sullivan 10 or 12 oz round style tank, and a 13X8 Master Airscrew prop if I remember right...

As far as the valves go, how do I check to see if they are adjusted properly? I do not have the tools that came with engine. Perhaps feeler gauges will work??

Thanks again for everyone's input!

Brian.

seanychen

My Feedback: (4)

Hmm, it does sound like you are not getting enough pressure.

As far as valve tappet adjustment, doing it on a day you haven't run the engine, you should close the tappet so there's minimum clearance. One way you can do it without a gauge is to see if it is free to move slightly left & right, but not noticeably up & down.

Phil Heller

My Feedback: (9)

Brian -

I am curious abouy the Y exhaust you mention. My 80 4st. just has a straight pipe - no pressure tap, no Y. Unless the manufacturer increased the size of the throttle throat in a later model than mine, you should not need any pressure. My 120R and 155R only run well on pressure and a Cline regulator, but my 80 and 90 never needed them.

I still believe your problem is in your carb barrel leaking air. Gas seeping around the throttle arm and carb spitting are not normal and indicate a leakage problem.

You do what you want, but if I were you that engine would be back at the repair facility pronto.

Phil

brian402

I should have been more clear about the exhaust. The "Y" exhaust manifold was on the airplane when I purchased it. It is a home made part that looks great on the airplane. The tap is only on one of pipes, so it's very possible that there just isn't enough pressure to the tank... I will take your advice and send it in for bench check and service. I'm now searching for the address to send it to.

Thanks,

Brian.

Phil Heller

My Feedback: (9)

Brian -

At the risk of repeating myself again - If all else is properly set up , you do not need pressure on this engine! Mine will run in any attitude and suck all the fuel it needs without pressure! It is one of the sweetest running 4 strokers available.

Phil

brian402

Thank you Phil,

In the quest to make my engine run as well as yours does, I will send it in for repair.


Brian.

rsmokin

My Feedback: (1)

Brian

Just picked up a new in box enya 80 4c and saw your old thread .
As I have heard mixed thoughts on these engines and assuming you got it working properly, what do you think of the engine?

Rich

The PIPE

If you DO end up needing a Conley/Perry "shaker" pump....

Dear Brian402:

The PIPE here yet again...and I've NEVER flown ANY of my four strokers, WITHOUT that NICE Conley/Perry "shaker" pump!

I am assuming you mean the pump I've included a photo of at the end of this message...these pumps are available from Conley at http://www.perrypumps.com/prod02.htm (the "shaker" pump is the VP-20 version)...and it's just about the BEST four stroke engine accessory I've ever used!

For your Enya 80-4C, based on where I had the shaker pump set for my twenty year old OS FS-90 REAR camshaft four stroker, a setting of 3/4ths of a counterclockwise turn, or 270ΒΊ open, from fully CLOSED, should be a great "starting point"...the piece you'd be adjusting is the hexagonal fitting on the OUTLET side of the pump, where the fuel gets routed into your engine carb from. My OS FS-90 used a setting of 300ΒΊ counterclockwise from fully closed...and NEVER was starved for fuel when flying!!!

Try everything that the other RCers have been suggesting first...and if you DO find you'll be needing a Conley/Perry "shaker" pump...now you know WHAT to set it at, at least for "starters", for your needs!

Hope this helped out a small bit, should you end up finding, that you DO actually need a Perry shaker pump for that Enya!

Yours Sincerely,

The PIPE!