captain america

iTrader: (12)

I'm rather new to Nitro... Very new in terms of actually starting to get my feet wet, in fact.

I had purchased a Novarossi P5X to put in my 1/8 buggy. I opened it up to do a quick inspection, and everything seemed fine, so closed everything back up and carefully used some high-temp silicone around the neck of the carb and backplate to make sure it was well-sealed.

Anyway, I mount it into my buggy, and try to start it up. Virtually from the moment ignition was made, the engine goes into high-speed overdrive! Literally as though I was full on the throttle. I checked my throttle servo, and it was indeed at idle. The carb is set to roughly 1-1.5 mm open at idle, so I don't think that's the culprit.

If it helps any, I'm running Sidewinder 30%, and I haven't really played with the needle settings; I took the needles out to inspect the O-rings originally, but I was careful to take note of all the settings before doing so.

The only thing I can think of would be some sort of massive air-leak somewhere. Also, the P5X has only three screws holding the back-plate in place, as the head of one screw broke-off with the shaft lodged in the crank case. I didn't feel that would be a real issue though, as I don't believe that the backplate is put under enough physical stress to be a problem. That, and I was sure to make sure that it was well-sealed with high-temp silicone.

Might anyone have any ideas on this one?

gatermaxx

iTrader: (6)

Tighten the head screws, make sure the linkage is hooked to the carb, make sure you have a return spring on your carb, pull that back plate screw off and put a new one in, use airseal instead of silicone, that stuff is mesy, and hard to get off.
HTH
Rod

captain america

iTrader: (12)

Hi gatermaxx.

I wanted to replace that broken backplate screw, but the screw literally broke roughly 1mm below the head, and the entire shaft is still inside the crankcase; impossible to remove without damaging the case itself, so I just left it. A machinist friend of mine said that it shouldn't make a difference, since the 3 remaining screws should be more than adequate to compensate for whatever loads would be imposed on the backplate.

Then again, I can't rule anything out. Any chance the engine could just be set too lean for the current cold, humid weather? (roughly 15C)

Thedub88

Sounds like the backplate is leaking air. If you only have three of the four corners locked down air can get in, the same as opening the carb at full throttle.

Did you try to lower idle?

adam lancia

iTrader: (2)

CA: it's probably not impossible to get the screw out. if it isn't bottomed out in the threads, it should spin freely. take a small pick and press it into the edge of the shaft of the screw then try to rotate the screw out of the case....i hope you know what i mean by that if that doesn't work, you can try a small dab of tire glue and some wire that's a little smaller diameter than the screw, let it set then try to spin it back out. hope that helps a bit,

adam

captain america

iTrader: (12)

Hi Adam.

Actually, the screw shaft IS bottomed-out inside the threads. That, plus the previous owner had put so much thread-lock in there that it caused the screw head to break-off in the first place as I was trying to remove it.

The only solution would be to drill out a new hole and re-tap it, but the screw hole is so close to the main opening that it could break through; hence my choice to leave it as is; lesser of two evils of sorts.

Crim3Wav3

iTrader: (8)

Well...a new case aint too much money...but you did buy a used (and in this case abused) pile...or so it sounds. You may need to just bag the old case and get a new, fresh one.

lesson learned.