Originally Posted by
skeller
The needles being wrong is what causes these engines to tune different. The "good tune" window is very small....and usually is found by using the lsn the most which is completely backwards from all other engines. Also...out of the box the needle settings are not far from race tune. People instinctivley reach to the hsn to lean out some during break in....it's almost perfect out of the box. These engines tune almost totally from the lsn.....sometimes even when you have high engine temps (280+ deg. F.) leaning the lsn will make it better if your hsn is set properly....usually around flush.
I also strongly recommend that everyone seal the slide boot to the carb....it can suck dirt in here. It will pull dirt while your WOT...then push it into the carb when off throttle. When the dirt builds up.......it falls into the engine equalling a bad day and a toasted engine.
My '08 PTM 3R is running great with no tuning problems....I will gladly help anyone with their tuning problems if I can.
Shane Keller
205-281-3089
thanks shane
as for the engine shutting off after removal of the GP, i get this sometimes when breaking in engines, the OS plug can sometimes be bad right out of the box, just the way it is, but also as stated before the hsn is set almost perfect, i now fatten it up befor breakin about 1 full turn, the lsn is set fat, this is what can cause the engine shutting off when you pull the GP. lean it on bottom some and it will idle when you pull it off, bump the idle up a bit and your good, i like to see little spirts of fuel popping out of the carb during breakin idle, this is telling me it's plenty fat on bottom and is well lubed, as you turn the lsn you will notice this go away, so leave it for the whole breakin. and with the HSN set a full turn out from flush it will allow you to tune in a more common way, but only lean till you reach flush or a smidge below, and then hit the lsn