Picco max has me scratching my head

[Bash]

I bought a picco .26 max off ebay. It supposedly had under a gallon ran through it. When I got it, I sealed off everything with RTV copper. Back plate, carb, needles, everything.

It's about 55 degrees F here today so I took it out for some testing. I have a problem that developed about 5 minutes into testing. The truck is running at about 200 degrees with a nice blue smoke trail.

The problem is that when I accelerate, the engine will cut out, but NOT bog. This isn't a bog problem that I would associate with being to lean. I've fiddled with the needles and nothing.

The engine simply acts as if I'm chopping the throttle. Say I accelerate and keep the trigger at a steady 3/4 throttle, the engine in the car will rev up like it is supposed to and then idle back down, then start accelerating again and idle back down. I took the engine off and noticed I had a leak around the exhaust header, sure enough I forgot the header gasket. I put a new one in and tested again... but nothing. I have changed glow plugs aswell and same thing.

The servos are working fine. That is not the problem. I have tightened the head bolts and the carb is tight...

any help?????

 

[Rolex]

I think you're set too lean. If it happens during acceleration up to half throttle, it's your LSN.

 

[Bash]

I tried richening it up to the point that it was very sluggish off the line with lots of blue smoke, but it would still cut out.


I picked the truck up and gave it a constant half throttle and it would just just as it did on the ground. I noticed that the throttle servo arm was actually closing and opening like it was fighting to keep a signal.

The thing is when the car is off the throttle servo works perfectly and doesn't flucuate at all.

What could cause that?

BTW the grass was a bit wet and I was running with the body off, but how could this explain the servo working perfectly with the engine off?

 

[Bash]

found the problem.. the wires connected to the throttle servo chip were ripped away...

can these be soldered back together?

 

[XxVASSAGOxX]

yea iv soldered servo wires, just be carfull and use tweezers

 

[Bash]

Well I tried soldering but failed. Hands aren't steady enough LOL

So I put an old 2018 traxxas servo in. It works alright for the time being. Gonna pick up a hitec 645 as soon as I can.

Otherwise the truck runs awesome. Wheelies like crazy. I'm just waiting for something to snap in the drive train! LOL