Back to Basics

Have I got it running? The SC started easily and ran, I'd left the main and slow running needles alone, I'd flushed the carb with new fuel and blown it clear.
It didn't rev above 7600 and it wouldn't idle without the glow driver connected. I reset the slow running needle, I left the main needle at 1 1/2 turns open as the manual states. I re-set the throttle with a pin in the air intake. I removed the fuel tank and cleaned it and the fuel lines. The tank bung was a bit loose and had been leaking. The engine is an easy starter, but runs slowly and the idle is erratic. I changed the SC plug for an OS F, no change in performance.
The engine doesn't have much compression, but its ringed so that's to be expected. Can't really do much with it as its hot and the neighbours have their windows open and don't appreciate the beauty of a tuned engine on song.

Checked the prop this morning, its 12" X 8", should be 11" X 6" or 7". Might make a bit of difference to the running.

Glad you managed to salvage the SC. It's been parked up for at least 15 years Brian, so a problematic idle until it's fully awake is, I suppose, understandable.

Brian in my experience an old engine like that may well be suffering from the needle valve O ring going hard/brittle or being worn. I have had a lot of old (15 years+/many hours use) 4 stroke engines over the years that developed idling problems and sometimes starting to cut out at full throttle, whilst in the air, nearly all of which were eventually cured by replacing the needle valve O ring after checking through all the other things you have been going through with the SC and fuel system. Might be worth a look, it is usually evident by the outside edge of the O ring looking a bit flat rather than rounded.

Thanks for the tip Peter, bit much to expect an O ring to last fifteen years without deteriorating.

I must admit that I've done a lot of fiddling with servos, control horns and disintegrating pushrods just lately. This evening I found that the rudder servo on the Panic had gone U/S. It was a 3003 and fortunately I had just one 3001 in my junk box (apologies to Futaba enthusiasts, it was not intended as a slur on the excellent quality of Futaba products). I extracted the duff 3003, and I was pleased that I'd remembered to attach a pull cord to the servo lead before I disconnected it. The 3001 replacement had been tested before I fitted it, the servo horn a sort of pull/pull arrangement was left intact, but when I pushed it on to the splines of the 3001, all was not well at all. It was a few degrees out. I searched my junk box once again, unfortunately it didn't have any spare Futaba servo arms. I tried the original servo arm rotated one hundred and eighty degrees... BINGO! With new clevises, the rudder is now fully operational. One aileron pushrod had broken, the clevis was on the aileron and the other end of the pushrod was on the aileron servo, but there was no sign of the missing bit. I binned all the original pushrod parts and made up new ones. What do I do next? The Panic seems to be set-up ready to fly, everything works including the SC 52 fourstroke, which after the latest tweaks starts, runs and idles nicely. I visited Cashmoor today, I enjoyed watching the models and chatting to the members. I haven't flown a model for over a year, but I did get a promise from Simon O that he wouldn't laugh if I tried to fly the Panic. I'll bring a black plastic bag, just in case.

Good news then Brian. Rememered where Cashmoor is :dry:

Good job the co-ordinates were still in the SatNav's memory!

Its been an eventful few weeks since I last worked on the Kadet. Today seemed good enough to get the building board out into the garden. I found that I'd not sanded the right wing tip, so I did that. Then I remembered that the rest of the week might not be very nice, I cleared up the workbench, slung away all the "useful" bits of balsa sheet strip and the odd piece of ply. Finally I got down to the bench surface. Then I found that one of my prefabricated hinge strips was missing, as was the needle valve for the OS fs.40 intended for the Kadet. Although I've been busy doing other things, none of these involved working on the "Kadet" bench. Odd that two small but vital parts are missing. I'll have another look tomorrow, but somehow I have a feeling that the needle valve will never be seen again. The hinge is just an inconvenience as I can quickly make another, but a needle valve for an old engine could be a problem.

The wing tips were finally sanded to airfoil shape and radiused to match the plan view. The latest Kadet "Seniorita" has a simplified wing tip profile generated by carving and sanding the underside of the tip only. This would have been easy to do, but it wasn't in the spirit of the original design, so using an old photo of the original Kadet, I spent a while in the sunshine making lots of balsa shavings and dust. Bliss! Final sanding of the wing went without a hitch (I usually manage to damage something) and as it was still a fine day, I brushed on a coat of sanding sealer all round where the covering will be attached. Final job for the day was to go over the sanding sealer with 320 grit sandpaper. Tomorrow looks like being a "stay inside" day, I might spend a bit of time drawing up a new bulkhead for a Bi-Stormer, but that's a project for another time. Not a good shot of the tip, can't get far enough from it to get it all in.