For the 19-20 tooth pulley Has any one mixed them? 19 in front 20 in rear? Or is everyone just running 19-19, 20-20?

I run a 19 in the front and a 20 in the rear. It helped in wide sweepers.

Thanks for the info

how did it helped you. and is it a high speed sweeper?

Rather obvious, it gives more spinning speed to the front drivetrain, ergo avoids losing the end on a high speed, loose sweep.

I've been running the 19F 20R "Overdrive" combo and I find it helps with my driving style on my track, which has a few sweepers on it, plus I find it helps me keep the nose up when jumping (more RPM up front to help get a little more gyro effect when punching the throttle in mid air).

NEVER run 19 on both, you will never get the belt tight enough and it won't do you anything different than running 20 on both.

Yes and no. It is time consuming to get to the diffs but not much worse than the Losi. The fact that most everything is 2.5mm is great, I cant tell you how many screws I stipped out just trying to loosen them on my SCTE. There are very few screws that come up through the bottom of the chassis so you dont have to flip it over while holding parts in or spend much time digging out that packed in dirt.

--Its all metric sizes.

2.5mm, 2.0mm and 1.5mm hex drivers
7mm and 4mm (i think its a 4mm) socket drivers

So which one is the O and which is the U?

19-
20-

What oil are you running in your diffs, and when was the last time you checked them? Also, what tires are you running and what are they running? I found a HUGE difference in punch after bringing my oil from 3k front and read (stock settings with properly filled diffs) up to 30K front and 10k rear, plus when our track was dry and loose, enduros worked well, but when we got a nice damp blue groove develop, the enduros sucked and hole shots were much better... If their tires are more suited to your surface, that could account for some of the difference as well.

It's different for the front and rear...your pully for the front has a different hub than the pully for the rear.

Of the 4 pullys that you should have, the 20 for the front and the 20 for the rear have no markings. The 19 for the front is marked with an O and the 19 for the rear is marked with a U.

Excellent explanation! thnx!

For some the O & U are difficult to see as the letters molded on the sides of the gears is very poor , even with good eyesight hard to see ....

Take a pencil crayon and rub the flat side of the pully. The U and O will show up much better. (Hooray for Kindergarden crafts!)

Speaking of kindergarden crafts, this past weekend's RCPS Canadian Nationals looked like the first few heats were going to be very wet, so I quickly made an inner-body for both my 2wd and 4wd out of a Pepsi bottle and some zip ties. Will post pics later, but it worked perfectly!

getting ready to start my build in a hour or so. Is a xp 1015 servo to fast for this truck?

Yea, the car used to want to loop out there, but now it just rocks around the turn. It helped me , before I got my sways. I still prefer the the 19 in front. Even on a tight track.