Do I need a governor to use the idle-up and throttle hold?

No!

What you need is a correctly matched set of pitch / throttle curves and preferably access to an optical tachometer so you can set your head speed correctly.

There was life before governors, I flew for the first 1 year without one and only really added one just because I love technology

Nope you don't "need" it but it makes life easier.

Welcome back Archie, long time no see.

I was curious about this even though I'm not at this level yet. Are there governors to keep the rpms level during the load changes on the engine?

Yep. The governor sits between the throttle servo and the reciever with a sensor and magnet on the fan. You tell the governor what engine speed you want and it drives the throttle servo to attempt to keep it there based on the sensor input.

BCH,
Thanks for noticing - I had some personal issues earlier in the summer and have been busy at work recently - Only just got back up to speed on my Raptor after a bit of a lay off and some teething problems with a new YS engine....which is sort of relevant to this topic.

I had always ran my old TT46 ProH on any fuel (15%, 23%, 25%) and it ran sweet as a nut on an OS#8. Never had to touch the needles - Never had a flame-out. When I upgraded my governor from a GV-1 to a CSM Revlock 20 I also had no problems.

But when I installed my shiny new YS50 and Hatori 3DII muffler and had broken it in, I had a hell(i) of a problem with flame-outs and a couple of fluffed (forced) autos because I was running a governor on an engine that wasn't running happily.

After some crash damage caused by a dead engine, I decided to leave the governor out of the loop and really debug the engine. I found that at my altitude, about 800 meters ASL, this engine is so far only happy on 30% nitro and an Enya #3. The last couple of weeks I have had some excellent flights without the governor, and just yesterday, I put the governor back in line for some very stable performance.

It was a good reminder that a governor is not going to patch up mistakes in tuning or set-up - you have to get the basics right first.

I always set up new engines w/o the governer. They mask tuning problems and the RL's run pretty bad surging and hunting with a rich engine.

Let me give you one thing to try, setup your RL on I1 in governor mode and I2 in limiter mode with a throttle curve about 10 points higher than you think you need in any position but the same head speed and see if it reacts better to limiter mode than governer. Its been my experience that some of the YS's just run better in limiter mode.

Thanks BCH, I'll give that a try next weekend.

The engine is running fairly sweet now, just a slight rough spot on initial spool-up. I think I am running slightly too rich because the power is not fully there yet (might also be that the engine has still only had about 30 tanks through it). But I would rather keep it a little on the rich side for now.

Had some great flying today. Brilliant, cobalt blue sky with not a cloud in sight or a hint of wind. Got to the field at 8:30 and it was 0degC but pleasant in the sun. By lunch time it was 12degC but felt much hotter with the sun on my back. Had to take my jacket off....perfect. [8D]

I did 5 tanks of Cuban 8's and high speed banking turns