Bought a NGF 172 kit to replace the damaged top end on my 180. Fitting instructions state to advance oil pump by 3mm and upjetting. Do I need to do this when fitting to a 180 or is it only meant for people replacing the top end on a 125? What I mean is do 125's have a different oil setting from factory compared to 180's? Even with different port timings I can't imagine why the amount of fuel and oil required for a 172 would change that much compared to a standard 180.
It won't hurt to much to richen the oil a little, the 180 runner has a 90 main jet as std so you could try a 92 ish? I alway's like to run a little rich just to be safe!
Thanks. I'll keep the oil pump advanced and see how it goes. I guess if it is too smokey then I'll know to back ti off a bit down the track. I was going to try a 98 main to start. I also bought a 96. I read somewhere to start with 10% increase and go down from there. Maybe this might be too big...
Try a big jet first then work down, the plug need's to be a nice dark chocolate brown to black idealy.
