ChitownRC

Hey guys. I've had my T-maxx for about 2 years now, though I'm still relatively inexperienced at tuning and such. I've only got around 2-2.5 gallons through the stock TRX2.5 motor, but since I haven't been using after-run (just WD-40) or keeping it completely clean (some external rust from grime), I don't think that it will last much longer.

Once my TRX2.5 decides to call it quits, I'm looking at something like a OS .18 (CVRX) as a replacement. I see a couple different carburetor options on new engines, and I was wondering......what the difference is between a slide-valve and a rotary carb??

As I mentioned earlier, I'm not the best at tuning, so that's something to keep in mind.

Welcome to the forums Kurt!

You want the slide carb as you have now to complete a direct drop in installation. A rotary carb on a t-maxx has issues with the linkage hitting the spur gear in a roll over.

Performance wise, the slide carb is supposed to be better in some way but I never noticed a difference. I've had both.

egglick Wrote:OS .18 (CVRX) as a replacement

Excellent motor.


Here is the one you want for the 2.5 maxx:
http://www2.towerhobbies.com/cgi-bin/wti...XGGP6&P=ML

They raised the price $10 because they have a sale going on.

You need this too for the clutch:
http://www2.towerhobbies.com/cgi-bin/wti...LXJF69&P=M


Here is the header and pipe combo I use:
http://www2.towerhobbies.com/cgi-bin/wti...LXAXN1&P=M
http://www2.towerhobbies.com/cgi-bin/wti...XSP47&P=ML

Tower hobbies raised the price on that pipe too. You should be able to get one on ebay for like $15.

Heres some pics of mine:

Awesome setup rob and not at all pricy. That is about what I ran on my RC10GT. Hehehe... lots of power and ver reliable.

As for carbs... I have used both and if you set the linkages up right I have neer noticed a difference.

I have that engine in my maxx right now. Great engine.

Rob, do you still run the stock motor mount? I am guessing that that is an old picture.

UE-Maxx Wrote:Rob, do you still run the stock motor mount? I am guessing that that is an old picture.

Old picture, I sold it to bottledbeast.... he probably broke it by now. :p:

I now run the dace mount.

Thanks for your help guys. If the linkage on a rotary is going to have issues on a T-maxx, then I guess that makes the decision easy.

I was kinda wondering how two differ in power and tunability though....just for future reference. They're both the same price, so I figured there must be some minor tradeoffs.

Some say the power from a slide is more predictable as the opening always changes by the same amount but I cannot notice a difference. They tune the same from what I can tell as well. The only thing is that a better carb will hold a tune and be easier to tune than a cheaper carb...

RobH Wrote:Old picture, I sold it to bottledbeast.... he probably broke it by now. :p:

I now run the dace mount.

Me too.

A book would say that the airflow thorugh a slide carb is going to be easier because it's going staright through, versus having to go around both sides of the ball valve that a rotary carb uses. so the air has to do this _/- instead of this ----. Once the throttle is wide open, there is no difference. Hopefully my diagrams make some sense to somebody other than me.