Problem Setting Throttle Lever

[arun 0]

I'm trying to tighten the nut that retains the throttle lever on my OS 46 AX engine as it was loose when I took the engine out of the box to install it. I'm having two problems...

 

Is there a trick to setting the throttle lever position and tightening this nut? I am finding that when I set the carb half open, out the throttle lever in the half-way position as dictated by my throttle servo and then tighten the nut, nothing stays still as the carb position rotates as I tighten the nut, meaning the whole mechanism is out of whack. What I want to do is set the the carb position and throttle lever half open and tighten the nut with everything staying perfectly still!

 

Ignoring the issues above, whatever I do I can't seem to get the nut tight enough, it works loose again very quickly giving me sloppy/no throttle response. I haven't tried thread lock as I was a bit worried about some of it getting into the carb and causing issues. Would this be a good idea, and how tight should this nut be?

 

Cheers!

[Jimbo 0]

Thread lock is OK on some carbs but not others - it all depends on what carb/make it is.

 

Am I right that as you tighten the nut, the arm moves to the wrong position?

 

Are you using an appropriate spanner?

 

Can you come up Sunday and I'll look at it for you?

 

So many questions....

[arun 0]

Am using correct spanner

 

Carb is an OS 40G fitted on the current OS 46AX as standard.

 

As I tighten the nut, the carb opening moves to wrong position. I.e. the arm is held in about the right position by the servo which is centered/neutral, but the torque to tighten the nut moves axle (?) itself, closing the carb...

 

Can't make it on Sunday, on family business sadly, but I am on holiday all next week so planning a good session all day Tuesday and/or Thursday.

 

Cheers!

[Jimbo 0]

OK, so here's what to do.

 

Set the arm where you want it, and try and do the nut up so you can gently move the barrel and arm to one end.

Move it to the far end in the direction of doing up the nut - which way will depend on the side the arm is on the carb.

When the barrel is at the far end and won't go any further, do the nut up while trying to hold the arm still.

It's at this time when you will have to have a few goes, and maybe back the arm up slightly so that it moves to it's final correct position as you tighten the nut.

 

Incidentally, the carb is half open when the leading edge of the opening in the barrel is midway across the venturi, and the sarm at this point should be at right angles to the servo push-rod. The servo output arm should be at right angles to the push rod as well.

 

Hope that helps some. Bring it to the field or to club night or drop round when you visit the field if you need more help.

Jim

[Nutz 0]

Set the half position,

 

Tighten the nut just enough to hold it in place

 

Undo linkage

 

Rotate carb to end stop

 

and hold the arm whilst doing up the carb to stop the arm moving as the carb cannot move as it is against the end stop

[Jimbo 0]

See now he's just repeating what I said!!! The cheek!

[Nutz 0]

Sorry, I read half way through and got lost.

 

Jim are you at the field tomorrow?

 

I am going Brighton in the morning but I am hoping to past the field late afternoon.

[Jimbo 0]

I hope to be there. If not, I'll be at home. Call me Dufus.

[arun 0]

Cheers Jim, Leon