jjscott

I just picked up a used Enya 60 4C. It's in very nice exterior condition but doesn't seem to have that much compression when flipping the prop by hand. It's been a while since I've run a four stroke and wonder if this just may be from the engine sitting a while or maybe they don't exhibit the same kind of compression as a 2 stroke when turning over. I can hold it on the compression stroke and it shows no sign of the compression bleeding off. I can see a bit of carbon on the exhaust valve stem; the top of the piston as viewed through the plug hole is clean. Maybe I just need to run it. Opinions?

The Wisconsin weather is finally showing some signs of spring, so there may be a decent day coming up.

Plus, I'd sure like a scan of a manual if anyone has one.

Thanks, Jim

Campgems

I'm not sure about the Enya, but the saito, magnum, and O.S. four strokes I have feel soft in relation to a two stroke. The Mag 52 almost feels as if something is broken, but it not. Also, there can be a huge difference betwee open throttle and closed throttle, the later preventing any air intake to compress. The real question is how does it run. If it starts good and will wind up OK, fly it.

You will get all kinds of comments about adjusting the valves and about pulling them and polishing the faces, removing shims, and other drastic "fixes". If it ain't broke, don't fix it. A tank of fuel, a fresh O.S. F plug and a starter will tell you if things are OK.

psuguru

I've had one of these for ages, but it's only had about 3 gallons of fuel through it since 1990 (!!) It's in a Chris Foss Acro-Wot right now and the combination is just peachy.
I'd say:
The compression does seem softer than an ABC 2 stroke. If it's holding at TDC then the valves and ring are OK.
These engines do not like oily fuel. If you run it on 5% Nitro, 20% castor it will gum up and quit on you at inopportune moments. The throttle response from idle will be "pants" too. Mine likes 10% nitro, 16% fully synthetic. Watch out for detonation, I've found that setting the needle by ear is quite tricky.
An inhibiting oil immediately after the end of the day's flying is a must as Enya bearings are notorious for rusting in the UK's damp climate.
The choke is prone to vibrating shut in flight. I took mine off in the end.
Tank pressure has never been required in any of the models with the Enya. I did try a Perry oscillating pump (VP20), but my problem was a cracked clunk tube. (Wanna buy a VP20?)
The Enya stock silencer kept falling off (it's a really bad design), so I fitted an OS silencer in the end and the noise is indistinguishable to the ear from an open pipe (but very bearable).

I'll scan my instruction book and send it to you as a PDF this evening.
Regards,
Carole Sherrington