Picco Problems

[Mike#18]

So after a long slumber I fired my Schumacher .28 Picco non turbo up. For the first few quick starts and idles. It ran great, amazing really. Fired right up after a prime.

I started, after the first few throttle hits having a problem when letting off the throttle after it had built some rpm. It would instantly shut down. I could get it to fire right back up but it would do the same after I backed out of the throttle.

Now after, say 5-6 starts. It will not start for anything and on the rare occasion it does, as soon as I remove the glow igniter it dies. Ive returned the carb settings to stock. Idle at .05mm lsn at 5.5 turns and hsn at 7.5 turns. The glow plug lights up bright and quickly. Fresh fuel 30% sidewinder.

Pic of my glow plug




I'm baffled and angered with this thing after so much excitment from getting it to fire up.
Help is appreciated.

 

[rcnut14]

good question. my f4.6 is doing the same thing. I've just been tring to tune it

 

[Jam Racing 1]

first thing I would do is install a brand new plug, check all my needle settings and go from there....also i would seal that Picco if you have not done it yet, while sitting the o rings can dry out some allowing air leaks in the engine

 

[timatworksg]

I hate when engines do that after slumber period. In fact, recently on my f4.6 Savage, I swapped from Sidewinder 25% to Byron 25%, being easily available...primed and couldnt start. You can hear it kicking and firing, but won't start to idle. I started leaning the HSN little by little and finally got it going, but the idle was running low...lower then when Sidewinder Fuel was used! Then all tuning was outta whack!!😡 Resetting to defaults, It wouldn't start to idle again! It was still firing...just not getting up and going. Did the same leaning to HSN while leaving my LSN and carb opening to defaults. It finally started but when applying throttle a little, it would stop. Started leaning the LSN now little by little till she could finally Start, run at idle, and I could drive her around, tho it was really rich!

Found it weird at first as with Sidewinder I had the needles turned in less compared to Byron. With Sidewinder, my idles were higher running and had higher temps running on grass! Not to say B is better then A, but sometimes different NItro fuel brands are made differently and throw tuning off alot. I was suprised at the difference how a little change can cause an effect! The engine is cooler with the Byron and on grass I hit 245F max! A first for me in a tropical zone!
My engine is sealed with High Temp RTV and had the exhaust cleaned out recently too. I would agree with Jam Racing on the sealing! It holds a tune and runs cooler after high speed passes!

In a nutshell, yes it gets frustrating, but your engine is working. A case of mixture maybe? Small leak? Perhaps default factory settings need some tweaking to your default? Open the carb gap a little, lean the HSN a little to reduce fuel flow in. Once running, let it idle sitting for abit to wake the engine up again.

I'm no expert, and still learning. But sharing my latest experience with a nitro engine in the hopes that maybe some similarity can help in your troubleshooting.
Something could be rich somewhere and/or something could be lean somewhere. Getting them close enough for combustion is easily frustrating...lol!

 

[Mike#18]

I know it was run and tuned on 30 % Byron's that's all it had ever run since new. I, however don't have easy access to Bryon's where I am at and this is literately the only 30% nitro my LHS can get. I have plugs en route. I bought a selection of med and cold's. Plug looks OK to me but what do I know about nitro 2 strokes <- not much
I'll try a re-seal on it. Even got a new tube of moto-seal.

Part of the frustration is that I'm in Canada and it's winter. It's frigid and I'm holding an aluminum handled screw driver.

 

[rcnut14]

nitro's don't like cold in my experience. don't know if that could be ur problem, but it sure doesn't help it.

 

[X]

I know it was run and tuned on 30 % Byron's that's all it had ever run since new. I, however don't have easy access to Bryon's where I am at and this is literately the only 30% nitro my LHS can get.

Byron's is good fuel. In your other post you say you are running Sidewinder now, and I can vouch for that fuel. I myself run sidewinder 30% and love it.