I recently bought an enya 60 4-stroke second hand....It is putting out no power and I have adjusted the high and low end needle valves...any suggestions on what to do next...
These adjustments were made with fresh fuel and a new glow plug...
Am I missing something?
Thanks

Hobbs:

If the valves are tight it will be hard to start and run roughly at low rpm, but the high end should be strong. If the valves are too tight it wont have much compression, still be hard to start, and not much power at the top end. What little top end it has.

If the compression feels good your problem is most likely not valve clearance. It is a good thing to check it anyway, even if you know the service history of the engine.

Enya four strokes are the "Odd ducks" of model engines, instead of having a single cam shaft they have two side by side in the rear case. If some one has had the cover off either or both cams could be out of time. My "Saito trick" for checking valve timing will not work on the twin cam engines, you have to pull the cover and check the marks.

It's also possible the ring is just worn out.

Pull the rocker cover and turn the crank to get the piston to the top of its stroke, if you see the rockers moving as you pass TDC turn the crank another full turn, get the piston between the compression abd power strokes at TDC. Adjust both between 0.0015" and 0.002" clearance. Nominal clearance is OK up to 0.004" but better power comes with the lowered clearance, and the valve gear has an easier time of it too.

Bill.

The cam timing gears sit in the housing one in front of the other, on my .46 MKII I accidently put the left one on the right and the right one on the left, they will go either way, and the top speed was off by 1,000 rpm. Obviously the cams are not identical.

If you take the timing cover off you will find two small marks on the shaft coming from the case and see two small marks on the timing gears...line them up.

Make sure the valve clearance is between .001" and .003".

After that it is all about compression and carburation.

I prefer to set the valve lash on each valve separately.

My point is placing the cam-follower/tappet/lifter on the middle of the base circle for each valve.
This would not be the situation with the engine set in the "firing TDC" position.

All that is needed is to turn the engine, with the valve cover(s) off, until, say, the exhaust valve is at maximum lift.
From there, the engine should be turned exactly one complete turn and there the exhaust valve lash should be adjusted.

Repeat the same procedure, for adjusting the intake valve.


It is possible for the camshaft to be badly ground, so its axis and the cam's base circle are not concentric, causing an incorrect valve lash, if both valves are set at the same time.

Thanks for all the info so far....
does anyone know a website that explains this with pictures?
Thanks again!

Hobbs:

Click [link=http://www.modelrec.com/resources/resourcesModelEngines.asp]here[/link] to go to the right page, then while there click on "How to obtain reverse rotation from Enya engines" to get instructions and a diagram. It also covers timing for normal rotation. It's a .pdf file, you need Adobe Reader to view it.

Bill.

Thanks for that Bill, my .46 times like the .60 and .80, whe I inadvertantly timed it like the .53 it ran lousy.