NitroOB4You

iTrader: (36)

Hey folks...Im having some problems I hope someone can help with.I am running an NOB4.I had the Colt 12 red head engine in it and it ran well...When attempting to start an engine, I would plug the exhaust tip with my thumb,pull the cord a time or two to prime the tank.This worked well with the colt engine.I recently swapped it out for an HPI Pro 12 SS...same as what comes in the
RS4-3 SS kit.I attempted to start it and it hasnt shown ANY signs that it wanted to start.I looked closer and realised that fuel was not being drawn out of the tank.I tried new fuel lines and another pipeand still got nothing.Then I took the SS engine out and sealed the carb and back plate with Permatex.Still, nothing.Through all of this,if I unplug the line off the carband pull the cord, it will draw fuel,just not when it is hooked up to the carb.Also, I noticed that if I pull off the air filter and plug the carb opening with my thumb,it will draw fuel.I have not attempted to start the engine with this method,so I do not know if it will work and conitnue to draw whenthe engine is started.I have always plugged the pipe outlet...was this wrong? Am I supposed to plug the carb opening?How does one prime the carb correctly?Or is there something wrong with the HPI engine?

VONEREFLEXR

I think your first problem is that your running an Ofna car.

Brett

unsrew your main needle till fule starts flowing, then u will be able to start it and go from there and putting your finger over the pipe is fine to prime it

TheRagunCajun

It might be that your main needle isnt open enough or even closed. Turn it out about 2 1/2 turns so start with. It might be a little rich or lean but fuel should enter the engine. Also make sure your fuel line isnt pinched anywhere.

Boomer

the reason that it will draw fuel if you plug the air opening is that the motor wants to pull something and if you block where it can get air (easiest to pull) it will pull fuel.

As Cajun and Brett said, looks like your main needle isn't open enough to draw anything but air. Open it up.

Always start simple - usually costs less

NitroOB4You

iTrader: (36)

Ok guys...thanks a lot...after reading your replies...I initially closed the needle, just to see where it was from the factory.I t was approx. 2 1/2 out.I opened it to approx. 4 1/2 turns out and it is looking good.Imma go out 'n play now .......


Moderators...please feel free to delete this thread,and thanks all

Brett

thats good i am glad u got things sorted

NitroOB4You

iTrader: (36)

Ok....now another issue...I got the engine started and it idles well,if...IF! I hold the wheels off the ground.As soon as I set it on the ground, it stalls.I held it for 1 tankful of fuel.This is where I stand now.Should I adjust the Throttle Trim?Ive always read that it is best to not touch the low end needle til after break in, so Im assuming the trim is my best bet.Or do I need to re-adjust my linkage? Any other ideas?

Brett

well u want to make the engine idel low as possibel so that way the wheels do not spin when ideling if u have the idel as low as it can go your clutch is too heaver or your spring is too weak

NitroOB4You

iTrader: (36)

Im using the HPI "racing" style clutch...with the wrap around spring.But, first you say,I should lower the idle? See if that works...if not,then experiment with the spring or the shoes?
If so, then I should adjust the trim or the low speed needle?Keep in mind,I have only run one tank of fuel , no where near complete break in?Im gonna try it now, by adjusting the trim and see what happens...I think this is best.Will let ya know in about 15 minutes, so if your still onlline...wait til then to respond to this, thanks

NitroOB4You

iTrader: (36)

Ok....the trim doesnt seem to help.So...I should look for a heavier spring or cut the shoes? Is this correct, or should I do the opposite?

Brett

u should look for a stronger spring or lighter shoes

u can do both thes things youe self

probly the easist way of doung tis is if u have a 2 shoe clutch with a wrap around spring all u have to do is cut it down bit but bit

u probly want to take 3 coils off at a time good luck

NitroOB4You

iTrader: (36)

I know I can cut the shoes....never thought about the spring...Ill give it a shot,let ya know in a couple days...thanks a lot

Boomer

It actually sounds like your shims are off in the clutch. I had the same problem with my 1/8th. . .your clutch isn't free-wheeling at idle, it's always engaged.

Check all your tolerances and make sure that you can freely spin the clutch bell without turning over the motor.

Once I did a little adjusting the shims, everything turned copacetic.

NitroOB4You

iTrader: (36)

Ok, Boomer...I am trying your idea first.The screw that tightens the bell, I had it tightened all the way, and this was binding it up.I had one washer behind this screw.I noticed that the bearing was recessed a tick below the inner rim of the bell, so I added a washer on the pilot shaft before I put the bell on.Still though, if I tighten the screw completely, it will bind up.However, I can loosen it about a 1/2 turn and it will spin freely.Given that I did use Loctite, would this be ok? Is there something I am missing here, when you say to "shim" it up?Ive never had any issues tightening this screw totally with any other engine..so Im not really sure.Maybe something wrong with the bearing or bell?