OFNA Ultra LX Comp - fuel line ???

[Sasquatch]

Hey!!

I just got this broken in but some advice needed...

During "extended" accellerations the engine is loosing power just as if it was too lean (and it is not).

Temps are good and everything seems fine. (220F w/o and 270F with body on)

LSN seems OK because of good punch off the line and regarding the HSN I think it is good.

I have noticed some small bubbles or atleast foaming in the fuel line to the carb. I have changed it out but still occurs.

Pheew finally to the question (sorry all but intro needed).. When I changed the fuel line i made the same routing and hence the same lenghts... This way of routing the fuel line and backpreassure line seems way too long for me. (Have inferno 7.5 also) Did anyone in here shorten them. Especially the one going from tank to carb.. That is only about 2" on my Inferno but at least 5" on the LX Comp...

Could this cause the inconsistant fuel supply ???

I suspect this to cause the cutting/power loss/erratic behaviour (sp)

Kind Regards from Denmark

 

[bOOm]

First off i think your engine might be bogging because it is too rich. I belive there is a thread somewhere on this forum about the length of the return-pressure line. The norm is 7 inches?

This might also help your engine temp which at 270F seems too high.

About the bubbles in the fuel line. no need to worry bubbles in the fuel line are completly normal and do not affect the performance of your engine.

 

[RatzoRC]

270 is hot for a .21 or larger engine in my opinion. I think it may be too lean.
Turn out the HSN out in 1/8 turn incrimants.
If that doesn't work, go to the LSN and do the same.
If it's running @ 270 it's not too rich, it's too lean.
Just my opinion

As far as my back pressure line, I run about 12 inches.

 

[jon2]

Ratzo, Have you changed length before and seen any change in performance?


12 inches Lol sorry I am only running 8 lol. I am happy with that.

 

[RatzoRC]

Sometimes if I'm having trouble holding a tune, I will lengthen the backpressure line and it seems to help.
It has helped me when all else has failed.

 

[Rolex]

The first simple fix you might want to try, since you just got through the break in, is to put in a new glow plug. If it acts the same, get back to us.

 

[jon2]

I personally do not like using the free plug the rtr comes with. I don't trust them and would rather tune my mill to the normal plau g I use if possible.

 

[Sasquatch]

Thank you all:

Jon2: I simply used the OFNA plug that came with it because it is marked as a medium tmp. Somewhere around the OS # 8.

I have OS A3, OS A5 and the #8's.

Rolex: Could it really cause this on/off throttle like behaviour??? if I use the supplied plug and I thought that the plug went completely "OFF" during break-in, not "half-working"


As you might have noticed I'm not an expert in glow plugs.... Just never having these kinds of troubles before.

RatzoRC:

I have used the break-in settings because I suspected it being lean, but the on/off throttle during accellerations still occured.

Regards...

 

[bOOm]

You might want to check your reciver for vibration interference. It might be messing with the throttle servos positiong. Just a thought.

 

[Rolex]

It's always recommended that you go with a new plug after break in. I've has a few glow plugs act weird when they glowed bright out of the car. I changed it and things worked right. It's just a maybe, but a quick check you can do to eliminate another possibility.

 

[Sasquatch]

Boom, Rolex:

I'll change the plug.

Radio should be fine. Unfortunately I have no way of checking during driving...

Iøll report back if I'm still having trouble.

Once again. Thank you all.