Ok so where are all those plastic carb lovers anyway? I really need you now! Well, I test ran the engine today and there was some good and some bad. The good is, the pump seems to work great. With the fuel line detached from the carb, flipping the prop delivers a healthy dribble of fuel. When I went to start her up she revved right up with only a couple of flips. What a surprise after 10 years of sitting!
Now here's the part that has me stumped. She runs fine at idle, fine at 50% all the way up to about 80%-90% but then at full throttle she runs for about a second, then the RPMS die all the way down to almost nothing like it's flooded and then she spins right back up again only to fall back down. It'll continue like that UP-DOWN-UP-DOWN until I lower the throttle.
My first thought is that maybe I shouldn't be running tank pressure with a pump? Is this just not necessary or is it actually detrimental too? My other thought is maybe it's the glow plug or fuel. I'm running 15% powermaster fuel with an A3 OS plug.
One other problem I'm having is the needle valve wont stay put. The engine vibrations rattle it loose very quickly so I have to hold it in. Any ideas to curb that?
Thanks in advanced to all those more knowledgeable than I
