Suggestions for O.S. .18 TZ base settings?!
 

I have an O.S. .18 TZ in my RRR and I have about 8-9 tanks through it now following the break-in procedure and I'm trying to get it dialed in. I'm having a helluva time with this thing!

Just when I think I have it right, the idle goes crazy after a pass and I have to run over and turn down the idle then it goes to normal, then dies. This is really screwing with me lol.

Can you guys post what your current settings all for all 3 screws so I can get it running better than it is so I can get this thing better dialed in?

Thanks!

First What pipe are you running. That could be your problem. Don"t touch that mid range screw.
Refer to your manual for factory settings. Then go from there. You can't be told over the net how to tune your engine.

I have the 1040 pipe that is in my sig, it's the one suggested by OS just for this engine.

I have the Mixture Control Valve and the Metering Needle set to the base spec per the manual. I have only been messing with the Needle valve during break-in and tuning as the manual also states to do.

I started with the Needle valve 2 full turns out from closed, which is the base setting for break-in. Then for the first 7 tanks I only closed it 30 degrees each tank as the manual suggested which after 7 tanks left me a little over 1 full turn more towards closed than the start position.

I'm now in the final adjustment portion of the manual, page 21. It says to do straight hi-speed runs turning the Needle valve closed an additional 30 degrees until it starts to loose power and not smoke much, then open it back 30 degrees.

This is where I am stuck at because every time I try a run, soon as I let off the throttle the idle is crazy high and I have to turn down the idle screw to get it normal, then it stalls. So I have to increase the idle with the screw again to get it to start and then try another run, same thing. Very frustrating.

Any ideas what the problem is?

O.K. it sounds like your low speed needle setting is lean. Here's what you should do. Set the idol screw back to normal or to a 1mm gap. Then give he low speed needle a full turn to the left or richen it up. You want to get the engine to start out sluggish. From this point run one or two tanks. This is just in case you ran it lean for too long. Now you can put the tune you want on it.
The manuals directions really depends on where you live. You should be good after doing this.

Awesome, thanks you! I'll give it a try this weekend!

How did it work for you?

I had my kids over today and I was working on my motorcycle. I'm going to give it a go tomorrow.

Thanks for following up! I'll be sure to post my results!

Alex

Hope it all works out. I love that engine. I all ways keep one tucked away just in case.

Suggestions for O.S. .18 TZ base settings?!
 

Hey man, I was having similar probs with my idle and then came across the os dyno review. Type (os 18 tz 11k tuning) in google and click the 3rd link down. The idle range for these engines ( for the 11K slide carb ) is 6000-7000 rpm. The slide gap of 0.3mm - 0.5mm is very critical. Then set your throttle stop screw so your idle speed is correct. From this point just refer to your manual for the other settings and your car will be flying! It is hard to tune over the internet for many reasons, but the main one is, all settings will vary heaps due to the place you live. Altitude, ATM pressure really play a massive factor for carburetors. Not only for RC cars but all vehicles that have a carbi! Hope I have helped a little.
Kind regards, Shannon