Originally Posted by
grizz1
Nice one vnmsgt. Those settings seem to solve most problems !!
I don't think the needle thing is really that much of an issue. Itīs more that these Go engines tune different from most other engines, and if thatīs the case, so be it. As long as the engine runs hard when you have the tune correct, you canīt ask for more than that.
The needles are very sensitive, especially the LSN, but once you get it right - bingo !! A lot of the guys running Goīs down here have the long LSN needles and we donīt seem to have too many problems. We have several really good tuners in our group that have the tuning sorted and the rest of us feed off their input.
I have just changed to a fuel with 5% less oil content than what I was previously running and found I needed to lean both needles just a little. LSN is now in just a hair over 2 3/4 and I leaned the HSN about 2 hours.
You have to allow a bit of leaway on those base settings to allow for fuel, pipe etc, but if you use the flush HSN / 2.5 in LSN as a starting point you are never far off it would seem.
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