Originally Posted by creaven
hey again guys posted a few days ago about this car i had it running perfect with 2.5 turns lsn and 3 turns hsn off the block it run fine for about 5 min off start block now it seems to want to idle around and if i give any high end it kills the engine . from experiance with motor bikes sounds like it is getting to much air, yet on starting block ( no wheels on a surface ) the engine is running how it should a few puffs of smoke on idle , and a light blue / clear at full throttel car will take a full tank and not over heat . yet put it down to run it seems to just want to idel about give it full throttel it will will it self . is this the LSN or HSN that i need to tune . and what way ?
Richen up the needles 1/4 turn counterclockwise. Now should tune your engine under load. You may be starving the engine. Ensure there are no leaks in the tank and fuel lines as fuel pressure is generated this way.
I use the spit test on the heatsink to see if it boils (greater than 100c) while you are finding the sweet spot you best run under 100c and then fine tune i from there. Run around for a minute or so till its well and truely warmed up.
Then slowly lean out the top end needle but not to the point of peak performance as the overall fuel flow is governed by it and if you need to richen your bottom (idle mix) you may starve it.
It's a balance of top needle allowing enough fuel flow and then the bottom needle to manage the mixture as you come off power and prevent any over run.
Please note, RC engine are very much tuned to be slightly rich on the bottom end and will in many cases richen up and stall after 4-6 second at idle.
One thing I didnt ask is whether the engine is completely run in, my Kyoshoi .21 was a pig to tune until it was.