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Jetting changes tested: the best so far!

2 posts in this topic

Taffy, your jetting recommendation worked the best. Thanks! The rear tire broke loose all day long (gears 1,2,3, 4th a little). Throttle response was instant and brutal. Cold start was hard, I just did it the one time at the start of the day so I have not figured out what the engine actually wants yet on a cold start. It appeared the choke did no good, but twisting the throttle twice, started it right up. Hot starts were first kick every time (with hot start button pulled out). The engine surprisingly had good low end power. Mid to top end is where it screamed! :)

Taffy, you recommended a 158mj and a 40 pj I believe. This is what I ended up with:

MJ 158

MAJ 160

EMM clip #4

PJ 40

PAJ 65

PS (2 turns out)

BK/APJ (very short, quick squirt)


Stock air filter

Header: YAMAHA Stainless Steel P/N-YZR-5GR93-10-SS

Muffler: Stock 98 YZ.

YZ Timed

Grey wire: (not unhooked), (not yet).

Gearing: 14 x 50 (stock WR raio-357).


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well done. after a couple of recent results i'm starting to feel human again.

your starting procedure will probvably alter slightly when you get used to it, day in day out.

i would have thought that you wouldn't need hot start but there you go. like i said ride it and see.


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