Engine over reving when starting

[DocHal 69]

I have a Savage X 4.6 using Roto Start to start engine. I set the throttle to 1/2 open with the trim on the controller for starting. I prim the engine by putting finger over pipe opening and running Roto start until fuel reaches the carb. The engine usually starts right off but revs out of control for 15 - 30 secs. then settles down and I can adjust the trim down to idle on the controller and it seems to run fine after, I am concerned the over reving will damage the engine or the drive train as the wheels are spinning like crazy.
Not sure what is causing this. The throttle control does not move. The low speed needle is flush . The high speed is in one full turn .

 

[Jam Racing 1]

You are starting it all wrong, you need to set the throttle endpoints on your radio so the throttle is resting on the idle stop, setting the trim messes up your idle settling, every engine I have starts at idle very well and if yours is not you need to retune so it will.....

 

[Jam Racing 1]

https://www.hpisavageforum.com/threads/list-of-useful-nitro-engine-threads.13941/

Read through all the threads on nitro engines and practice tuning.....

do you start your 1/1 vehicle at 1/2 throttle or more? of course not, same thing applies to your nitro model engine.....

 

[DocHal 69]

Ok Thanks, I put the settings back to factory and it started with no over revving. I warmed it up and tuned it until it was accelerating and running good but not doing wheelies. I found when it stopped and I tried to restart it doesn't want to start without giving it a little throttle or making the high speed adjustment a little richer. Its only 9 deg C here and the engine is only getting up to about 190 Deg after running for 10 min.
Any suggestions for starting when engine is warmed up?
Thanks Doug

 

[js1badsti]

technically it should start easier when warm then cold.You may have a wornout motor with a loose piston or may need a fresh glow plug.

 

[olds97_lss]

When starting, I usually hold the remote in my hand as I hold the truck with my palm and apply a little throttle, then when it starts, I can quickly let off. Or, I hold the carb open a bit with one hand will pulling the start with the other, if the truck linkage allows for it.