Hello,

I read Homebrewer's sticky thread and I'm trying to run my older Enya SS25 for the first time. I don't have the manual. Would someone be able to help me identify the 3 items in the picture. So #3 is the needle. What are the screws #1 and #2? Can you identify the high end needle and low end needle? I'm trying to set these up and unfortunately don't know what's what. Thanks in advance for the help!

Number 2 is the air bleed screw, which controls the idle mixture. At the front of the carb is a small hole, which admits air. This hole is varied in size by the air bleed screw. Thus, the idle mixture is controlled. Screw in ... richer mixture.

Number 1 is the throttle stop screw ... sets the end-point for the travel of the throttle barrel.


AFAIK



Below is Pe Reivers' advice on tuning an air-bleed carb....probably reliable advice.



Airbleed setting is shut off past half throttle, so it does not influence the high throttle end of the game.
What does this mean?

first set the high end for anywhere near decent running. Idle bleed is shut off, so of no consequence in this procedure. Point the nose up 45 degrees, and just get her off for-stroking rich. There is NO NEED to go back and forth.

Now turn your attention to the idle setting. Start with a high idle rpm, and find the best rpm, again with nose pointing up.
reduce idle speed, and adjust again. Acceleration should be crisp. Repeat at ever lower idle, until the engine refuses to obey your commands. Now you gave reached the lower rpm limit.
Adjust the engine some 200 rpm faster than that. Keep checking for crisp acceleration, even after prolonged idle.
By this time, about three minutes, you know the engine well enough.
Go fly, and make any minor adjustments you deem necessary.

#1 is the throttle stop, just set it to not hinder the servo on the low end.
#2 is the airbleed screw, sets the mixture at the low end. Unscrew for more air and a leaner idle. This screw should be set to ensure a good pickup from idle rather than the lowest idle. A good starting point is when half of the airbleed hole is covered.
#3 is the main needle, set it at full throttle on the rich side of fully lean. Starting point is usually around 3 turns from closed.

The throttle stop screw also holds the throttle barrel in place. The barrel rotates with the throttle arm. Make sure your bleed idle screw is not repeat not all the way in, or the engine will not idle. You can use a straight pin or needle to see if the hole is open. Some people insert the needle and set the idle screw up against the needle for starters. If no one has touched it and the needle test shows it is open, then it is probably set correctly.

Three turns on the high speed needle is usually very very rich. Good for starting but a more normal setting is 1.5 turns out. IMO, two turns is plenty rich to get you going. Read the tuning thread at the top of this topic for help.

I just realized something else; the head looks wrong. You'll want the fins to be oriented along the airflow for an airplane engine. The SS25 should be a BB engine with ABC construction, but yours doen't seem to have the front bearing on it (the spinner is in the way too though). If you have the oldschool, piston- baffle, engine you might have a car head on it, but if it is ABC you can simply turn the head 90°.

If/when you run it make sure you use plenty of castor oil in the fuel if it is the old-school iron/steel construction.

Thanks everyone for the feed back. Sorry for the late response, we were evac'd for the hurricane.

Surfer_Kris - thanks for noticing the head being aligned wrong. I'll correct that. I take it BB means big block and ABC means it has a cylinder sleave? If that's the case, yes, it does have a sleave. I bought the engine about 1986. I emailed Enya and they sent me a replacement manual but it was in Japanese.

Hopefully with all this advice I can get it running.

BB is Ball Bearing.

BB stands for ballbearing. SS stands for "Super Sport" and these are usually ABC engines (i.e. modern schneurle ported engines with aluminium piston and a cromed brass sleave). On ABC engines you can rotade the head, while on the old school cross scavenged engines you cannot, as there is a baffle on the piston and a corresponding groove in the head.

The crankcase of the engine in the picture does not look like the SS double BB engine. It might therefore be a single ballbearing non ABC engine. With the head off you will easily see if it can be rotated or not.

Hoss,


As Kris already wrote, assuming this engine is intended to be used in an airplane (or an airboat/aircar), the head should be set with the cooling-fins in-line with the airflow.
I.e. they must be oriented front-to-back - not side-to-side as they appear in your photo.

Tighten the head-bolts gradually and evenly, or the head shim might not seal and the engine will be 'a dog'.


Dar

The SS25 is Schneurle ported so the head can be realigned with no problem. The OP's engine appears to be the plain bearing version because the BB has a wider front housing to accept the ball race. These engines use a cast iron piston and steel sleeve so a fuel with quite a bit of castor (preferably all castor) should be used.

There's no head shim listed in the parts catalogue so I'd guess that, like most Enyas, they don't use them. When fitting the head, nip up the first head screw until it just barely seats then fit the opposite screw the same way then do the remaining two. At that point I twist the head a couple of times as far as the nipped screws will allow just to make sure it's seated before slowly increasing their tightness using the same sequence. Don't overtighten, just a firm pressure on the allen key.

Not all SS engines are Schneurle ported ABC engines. The .15 ones are, but in the larger sizes there should be an additional X or CX to denote ABC or AAC.

Removing the head will easily show what engine type it is. A peek through the exhaust port will do it too.

Just checked the Enya website, there is an SS 25 engine that is nothing but the plain old-school engine, i.e. plain bearing and iron/steel construction....

Thanks to all the good setup suggestions, it's running.

I posted a video of the test run here:

IMG 0010 (1 min 10 sec)

I have the needle set at 1 3/4 turns from closed. Also, I think the exhaust gasket is leaking. I seem to be getting a fair amount of liquid fuel showing up on the engine itself. Another observation, the starter damages the spinner. Any suggestions for this? Maybe a better spinner.

Thanks

Yep, plastic spinners + electric starters do not mix. Splash out on a metal spinner or domed prop nut.

Engine seems to run well enough, though.

Originally Posted by Hoss87

Also, I think the exhaust gasket is leaking. I seem to be getting a fair amount of liquid fuel showing up on the engine itself. Another observation, the starter damages the spinner. Any suggestions for this? Maybe a better spinner.

Liquid fuel on the engine usually comes from the carb, there is a bit of back-blow through the carb on the down stroke. As for the spinner, just hand start it, you don't need an electric starter...