CTurbo

This is a Mega Picco ZX .21 version II mounted on a D8. It was a new engine that is having the same problem since new. It runs perfectly only with a new glow plug (hot MC-59 or OS LS3). Once you run 4 to 5 tanks the engine start to flame out when you open the throttle or backfires and dies when I open the throttle. Put a new glowplug and the engine runs again perfectly. Put the old glowplug on another engine and the other engine runs fine. I am talking here of a new engine with a lot of compression and mechanical pinch. I have worked with nitro engines since 2001 and fixed some "difficult" new engines. I am about to give up on this one.

j_blaze14

iTrader: (34)

check tune, fuel line, tank, headbutton, head, check motor for leaks. if all that fails see if there is a warranty. also if its not "fully" broken in it won'r run right hot or lean, still needs to be on the rich side with plenty smoke. i've seen motors seize up on the straight if there was too much pinch and not enough lube.

bigguyrc8

iTrader: (1)

im not an expert but it sounds like it still needs some braking in time,im doing a nova p5xlt and been having same type of problems.how much fuel has been though the engine? mine was real tuff at first would hardly go or take any throttle,now it is getting much better(1/2g).good luck

Jaz240

iTrader: (52)

Check your deck height also. It may not be shimmed correctly for the fuel %

CTurbo

Deck height is actually .018" and I have gone as far as .035"+. I have run 2 Gallons of Sidewinder 20% nitro. I actually race this motor every weekend. It just gets too expensive to change a glowplug every main. I changed the fuel lines and also ran a less than perfect "practice motor" on this chassis with no problems. I just don't want to give up on this very powerfull motor.

heidmann1

iTrader: (22)

its to lean, either on the bottom or top, I would back you needles out and start over with the tune.And make sure you arent too lean, If you are not you have a air leak somewhere. Sometimes it takes a couple tanks of fuel for the metal of the engine to expand slightly and thats when the small air leak will Show itself.Cap off tight ,the carb,fuel fittting and exhaust port, Place the whole engine in water and turn the flywheel over and the crankcase pressure will show an air leak if it has one. BUt if oyu do this you will have to dissasemble your engine and make sure any moisture is out and oil it just in case. ???

houston

iTrader: (96)

Excessive rod slop will eat glow plugs like crazy. Picco engines that I have experienced in the past have to have a very rich bottom and a little leaner top. Are you referring to the deck heighth or the shim stack ?

CTurbo

I am talking of head to piston clerance messured by the solder - caliper method.

houston

iTrader: (96)

Absolutely perfect Cturbo !!!

Just got to ask cause you never know , you know what you are doing .

Have you tried a cooler plug just to see what the results are ?

I have had engines similar to what you are describing and found a cooler plug to withstand the engines running better than the hotter plugs .

I don't have a lot of exp. With the picco engines but I used to run them in like 2001 or so , picco G1 XP . Always a pain in the butt but when it was on it was on .

CTurbo

I tried MC-9 and some cold GRP and both seem too cold and agravate the problem. I will hear and try any sugestion of a paticular model of plug.

houston

iTrader: (96)

Do you work on your own engines ?

Have you performed a teardown on the engine and checked the internals?

Monty

How did the plug agravate the problem C ?
Just curious to know

MontanaMaxx

iTrader: (12)

I half to say this is some great information Houston. Expirence is simmilar lean the bottom to much and its fatal

CTurbo

Last night I disasembled the engine, found nothing, sealed back together, did the fishtank trick with the engine and with the fuel system, tried a medium OS 5 glow plug and gave it a try. As expected, it preformed well until with the new plug until the third tank. It began to act up again. Took a break to cool down but it makes no diference. I am cool, just dont like defeat

CTurbo

The carb did not have the venturi. People kept saying that it was not necesary. Today I instaled a Nova venturi that did not fit and the engine worked Ok for 1 tank. I will have to wait to get to the track to do the real test. Tell me about your experiences when removing the venturi.

vladconnery

iTrader: (35)

Picco engines are plug picky engines. The correct plug is a picco plug other than Odonnels I never had success with any other plug in there engines. The picco button taper is different than any other engine. Using mc's or OS is a bad move. Had the same problem with my picco's until I swicth to Odonnels 99's 0r 97's. I really got rid of the problem when I trashed there engines and went Novarossi. Don't get me wrong they are good engines strong and fast. Just to much of headache for me.