# jets



## grizz825 (Feb 20, 2011)

hey guys i got a 99 grizz 600 and i im putting a hmf slip on on it. and i was wondering if anyones knos whats the main jet size in them? hmf reccomends a 175 but the mech. at the local yamaha shop said you really shouldnt have to jet it since its just a slip on but he just said if so then just go one size up. thanks


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## wood butcher (May 11, 2009)

i would use what they recomend, its gonna be a good startin place


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## grizz825 (Feb 20, 2011)

ok well i think but not entirely sure but yamaha said its like a 142-145 and hmf said run a 175. ill pull the stock jet to see for sure thanks for the advice


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## jrfonte (Mar 9, 2010)

If I'm not mistaken I beleive hmf uses dyno jet jets they are not the same as OEM mikuni or kehien jets say a 170 dyno jet is the same as a 150 of the OEM ones this is not exact but just a round about figure but dyno jet sizes are around 10 or so numbers higher than OEM for the same size jet. Jfyi


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## grizz825 (Feb 20, 2011)

ok well then thats why there a big difference. like i said they say its a 175 main jet recommended from hmf and the stock is like 142-155 i couldnt really understand wat the mech said at my local shop but ok thanks for the info really appreciate it.


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