I have recently recieved 2 royal 46 engines from a freind. One has never been run and the other is dissasembled. I tried to look up a manual and spec sheet for them but can not seem to find any thing. Any-one know where else I can look?

Royal were marketed by MRC If I remember right for a number of years (Maybe it was Altech?). Over the years they were made by 3 different companies.

The last ones were made by LEO of China and were copies of the OS 46SF series of engines. They were a moderately powerful ball bearing engine and they didn't give much trouble.

Just Engines in Great Britain in recent times sold LEO's and also under their own brand of J'EN. I don't know if the current J'EN engines are LEO's or SK's

Thanx w8ye. I've seen your replies and have read alot of things you have responded to in this forum. You seem to be "fairly schooled "in the field. I really appreciate your help. I fired this thing up last night after soaking it for a while. It had never been run and was a little stiff so I let it saok in some warm to hot 10% for a few hours, cleaned it up and presto nice and free, smooth, and it runs great. I have another with a new sleeve piston rod and bearings just hasn't been assembled. Hence I wanted the specs for it. No doubt I can figure it out but having the book is a plus in my book. I'll never know it all. If I run up on something I'll just post my query here. Thanxs again. P.S. One day you'll have to explain that screen-name to me!

Treat the Royal as if it were a OS 46SF and you will be fine.

The engine is ABC and not ABN like some of the OS engines

The last MECOA 46's are the same as the last Royal 46's
http://www.mecoa.com/mecoa/46/4603.htm
http://www.mecoa.com/mecoa/guide.htm
https://shop.mecoa.com/shopdisplayproducts.asp?id=146 Parts list

If I may intervene, what is the difference between a royal .46 and a royal .45? I Have a .45 with a manual, I can copy it if it would help anybody.

The 45 is older and actually no parts are interchangeable with the 46.

I think the 45 was made by Thunder Tiger?

The 45 is a clone of the OS 45 FSR and the 46 is a clone of the OS 46 SF. Royal engines were manufactured for and distributed by Royal Products of Denver, Colorado.

Here are those 3 engines from my collection - the OS46SF, its clone the Royal 46 and the OS FSR look-a-like, the Royal 45.

In the 1st pic is the OS 46SF & Royal 45 - as W8ye mentioned, totally different engines with nothing in common. The 2nd pic shows the Royal 46 on the right (minus carb) - very much the clone of the OS46SF on the left.

Mountainroad - yes thank you, I would appreciate a copy of the Royal 45 manual. I will send you a PM with my email address [8D]

Here's another pic showing the "cloneness" of the Royal 46 alongside the OS46SF.

I've also posted a pic of the Royal 45, it comes with a little story to tell. I purchased the 45 second hand & when I ran it, its performance was extremely disappointing with its max RPM about 3,000 less than my OS46SF using the same prop, plug & fuel. I pulled the engine apart & to my amazement found an internal "modification" performed by the previous owner. One of the transfer ports (the one immediately behind the "Royal 45" badge casting) has been blocked off with one of those hard setting metal type epoxy fillers. After approx. 45 minutes of careful scraping, I had removed all of the filler. Re-assembled the engine, fired it up it & its performance then zoomed to be on par with the 46SF (actually 200 RPM less) [8D]

Even tho the Royals are clones, take notice that the carb are held in with a draw bar on the Royals and on OS engines there is a threaded screw on each side

Does anyone stock parts for the old Thunder Tiger (2 part crankcase) Royals? I am wondering who bought out Royals parts inventory when they ceased trading.

Fiery You might try MECOA . This guy buys up all kinds of stuff from old engine manufactuerers , just a guess martin

Looks like W8ye aleady stated this missed that

Everything that I have bought from RJL/MECOA has been of stellar quality and has provided terrific long life and service. Just thought I'd throw that in there. Lots of folks haven't dealt with them the way that I have and don't have a clue as to how they do business. I've been satisfied with everything that I have bought from them.

Oh, and I bought and flew one of those early MECOA .46 engines that W8YE mentioned. It used a K&B .61 muffler (also stock for HB .40, .50 & .61), which made it very quiet. It ran beautifully, both on the bench and in the air, plus it was the quietest mid sized engine that I have ever owned/flown.


Ed Cregger

good afternoon, i wonder if i might impose on you for a question?? i just took possession of a royal .25 r/c ABC schneurle ported..... it doesn't have a manual but i'm on forty years of breaking in and finger breaking. can you tell me what prop range is ok for this engine? thank you in advance for your help.

fly safe and often, bill

Both the Royal 25 and 28 like 8-6, 9-4 and 9-5 props.

That Royal 46 on the picture is very much looking alike a SK engine.