Tri-Z issues

[86350xman]

I'm having issues with the Tri-Z dying after I run through the gears and let off the throttle. If anything, it might be a bit rich looking at the old plug, but still seems to pull hard and has great throttle response. I know the pilot is a bit lean because you have to crack the throttle to get it to start, but after it's started it'll idle just fine. Once I take it out and open it up through the gears, as soon as I let off the throttle it wants to die and bogs if I try to give it some gas to keep it running. Once it clears out, it runs fine. I'm just wondering if this is either (A) running so rich it's flooding itself when I go wide open, or (B) sucking all the fuel out of the bowl on a hard pull and starving for fuel. It doesn't have any issues other than this. It runs great, has decent power, doesn't bog when in the throttle like it's running real rich, or break up at higher RPM like it's running lean. It's still got the factory fuel tank/fuel pump, and full airbox. The only thing on it that isn't stock is a larger 36mm mikuni carb. It's still got the factory exhaust on it too, which is full of 25 years of junk. I plan on swapping out to a new DG exhaust to see if that helps at all. Anybody else ever have this problem, or maybe a suggestion on how to correct it?

[TimSr]

Id be looking at the float level first, especialy if its got the brass floats in it. They start to sag over time, and have to be rebent upwards after a while. I had one with sagging floats that would cut off flow every time I was climbing a hill! While you're in there, pull out all the jets, and the air screw, and blow air through every orifice. Also, take the fuel pump apart, and make sure the diaphram is not cracked, and the two one way valves are working right. Also, check the vacuum line for leaks. I had one that kept dying at low R's, but ran fine at high rpms, because the vacuum hose was cracked.

Id had several issues with the 36mm Mikuni. First off, if you have a stock motor, its probably not doing anything for you besides making life difficult. Even with a ported motor, I got better performence out of the 34mm Mikuni. The 36 robbed a lot of low end. The other issue with the 36 was the TriZ slide and needle I tried to run with it. I was way lean on top, and way rich on mid. I found that the needle jet was much larger on the 34 and 36 than the stock Z carb, so I ended up getting a larger needle that was more typical of that needle jet. I wish I could recall the size offhand.

[86350xman]

I'm gonna replace the fuel pump with another one I have and see if that helps. I would think that the pump is fine because it'll sit there and idle all day long if I want it to. I can rev it in neutral several times and let off the throttle and it will idle just fine. It only happens when it's under a load and you immediately let off the throttle. The carb is brand new and has been pulled all the way apart, all orifices cleaned. Using the needle and slide that came with the carb, clip set dead middle. It pulls hard, still seems to have good power all over, just seems like it loads up after a hard acceleration and doesn't want to stay running. I just can't tell if it's runnin out of fuel, or flooding itself.

[jonolanracin]

what does the sparkplug look like if its wet your rich if its gray or white its lean