popsracer

Guys;

Just bought a new RB-V12 and the slide carb is sticky just above the idle stop.
Even with 2 bands to pull the slide back, it sticks untill I push some brake and the linkage forces it all the way back. Everything is set correctly too.

None of my other NR carbs have ever had this problem.

Anyone else have this problem before and did you find a cure?

Thanks, Steven

sparksy

iTrader: (14)

I had thet same problem on a Tr I had a while ago. I took the carb appart and found a bur on the slide.

Bob The Builder

Here in the UK - RB had a sticky slide problem with the carbs on the new WS7 II buggy engine not long after it was released.
It turned out to be a tolerance problem during manufacture.

I wonder if they are having the same problem with the carb on the new V12 engines.

I'm still running my trusty X12T - 5 port but will be getting a V12 when it needs replacing.

Be interesting to know what the actual problem is when you find it.

Fisher890

I thought I had a sticky slide on my RB C12 103 after I Put a heavier return spring and springs on both sides of the throttle linkage.RC10GT (am radio POS) it was much better But I have noticed a shiny 'groove' on the slide plunger. I readjusted both springs and carb angle after running it yesterday and have to have both springs set VERY aggressively tight for WOT and TCT. Everything seems to move well now though.Fastharry had RB Carb burr issues too but they were at the neck.Sounds like a small burr to me. I Have a gallon+ thru mine now and am starting to get a tuning clue (I think...).Only my second nitro so what do i know? But in a fishing reel if it goes click when its not supposed to its a burr........or sand...

Bob The Builder

Been speaking to some of the other racers here and one of them also had a sticky carb.
It turned out that he was running the bottom end too rich and had the idle stop screw wound in to keep the idle.
The end of the idle stop screw was rubbing against the slide and causing it to be stiff.

Try unscrewing the idle stop screw by a full turn and see if the slide goes free.

popsracer

Bob The Builder;

Yes, I have tried moving the Needles already and it did not make a difference.

I may just have to disassemble the carb to see where the problem is.

Thanks,

popsracer

Guys;

Just wanted to let everyone know that I found the cause of the sticky Slide on my Carb.

I disassembled the RB carb along with a spare NR (which doesn't stick) for comparison. I did NOT find any burrs on the idle stop or low spd mixture screws.

What I did find was where the low spd. mixture screw (male) enters the mid range needle (female) was not fitting properly and causing the sticking.

Upon further investigation, it seems the Threads for the low speed mixture screw and slide barrel are sloppy. This poor fit is causing the low needle not to center itself in the slide barrel. (you can see this if you look very closely)

I swapped out the slide assembly from my spare Carb, re-tuned the Engine and everything works fine now.

Thanks for your replies,
Steven