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View Full Version : Tri Z jetting?



jsimonh
08-09-2005, 10:26 PM
I been gone the last two days to my father's farm. I checked the needle to see what notch it was on, and it was second from the top. When I ran it WOT it seemed to be flooding, so I moved the needle to the top notch (as lean as possible). This seemed to really make it scream and have a smooth acceleration. So I put in a new plug and did the whole "plug chop" thing. Plug was light brown/tan. GREAT! :w00t: Then after riding awhile it started acting up, like it wasn't getting enough fuel :wondering . So I moved the needle from top notch to third notch (one richer than I started). I did a plug chop again and it was a little darker but not much at all :confused: . So then I was confused at how 2 different needle settings could create the same looking spark plug. Both times I was running with no airbox lid and it had smooth acceleration. Currently it's still on the third notch and gives a good spark plug reading, but if you run it at a constant speed it acts like it is hesitating. Any ideas?

It's still got all the factory jets, and the fuel pump squirts gas a little when I unhook it from the carb and kick it over so I don't think that is the problem.

MTS
08-10-2005, 12:04 AM
the needle is only in affect up to about 1/4-half throttel, i.e acceltation, if it is surging on the top end i would try a smaller main jet, it could be getting to much fuel or there is a small tear break/rip in the vaccume line/pump

twgranger
08-10-2005, 03:50 PM
What year you have and what size main jet? You should be changing the main jet not the needle.

jsimonh
08-10-2005, 05:23 PM
What year you have and what size main jet? You should be changing the main jet not the needle.

It's an 85 Z. The main jet is still the stock 470. Could you give me a hint as to what size I should change to, and point me in the direction on where to buy the jets?

It just has a hesitation or stumble feeling when the throttle is held at one position.