Air fuel ratio??????

[MiDnIgHtKat]

Having issues with the air fuel ratio i have 170 jets and a vanes and hines exaust on a pre 600 the guy i bought the bike from tore the carbs apart and rebuilt them and has the air fuel all out of wack i was wondering if anyone could help on setting them from either screwing them all the way and backing them out of vice versa

[kevin2502000]

2.5 for stock probably 2.75 with your header.

[MiDnIgHtKat]

from taking it all the way in or vise versa?

[Tmod]

First question we need answered is do you have a jet kit on the bike? if you don't know take a cap off one of the top of the carbs and pull a needle and check the grooves on the needle. Do you have more than one?

Tmod

[arsenic]

170 main jets??? why??? 88-89 600 stock are 137.5 outer and 135 inner, 90-97 are 112.5. Your OEM Mikuni main jets are 112.5, why do you have 170 main jets?

[The CyberPoet]

170 main jets??? why??? 88-89 600 stock are 137.5 outer and 135 inner, 90-97 are 112.5. Your OEM Mikuni main jets are 112.5, why do you have 170 main jets?

+1

That's way out of typical range, even for a stage 3 jetkit, V&H exhaust AND an aftermarket air intake system (pods). My initial advice would be to not putz around and instead go find a dynometer with an exhaust gas analyzer and get it jetted correctly the first time around.

Cheers,
=-= The CyberPoet

__________________________________________________ ________
CyberPoet's Katana Maintence and Upgrade Parts Offerings
The Best Metal Steel Aluminum Motorcycle Tire Valves in the World, plus lots of motorcycle & Katana (GSX600F / GSX750F) specific help files.

[quik89Kat]

170 main jets??? why??? 88-89 600 stock are 137.5 outer and 135 inner, 90-97 are 112.5. Your OEM Mikuni main jets are 112.5, why do you have 170 main jets?

start with seein if it even really has a jet kit evident by slots in the needle ...you take the carb top off lift out the spring and spacer and use a thin magnet to lift out the needle carefully...there may be washers on them dont lose those remember how it came apart ...if there are slots put the e-clip on the 3rd slot down from the top slot do this to all of them and reinstall all the caps as you go.

next drain the carbs or shut the gas off and run the bike til it dies...pop off the carbs turn all the pilot screws in til they bottom gently then set all the pilot screws out to 2-1/2 to 2-3/4 turns out (helps to put a small dot on the tube even with the screw slot turn out from there)...

next pop off your fuel bowls and tell us what jet you really have I assume the P/o was full of crap or had no idea how to tune a bike if it has a jet kit it probably has the right size jets as arsenic mentioned if they are a few points higher then your stock size
but 170 is waaaay too big...
go to a bike shop and get the correct size if its a factorypro jet kit as they use stock mikuni jets...

if they are dynojunk..um dynojet check their website for the correct jet size if it has a dj stamped on the main jet this would indicate that
and you have to get dynojet main jets to match the dyno jet needles....put the carbs back together and install them on the bike

if you did have 170 main jets change your spark plugs they are fouled to crap..start it and take it to get the carbs sync'd by a dealer and your all set

[arsenic]

it's way easier to tell what jet kit it is by the grooves in the needles. 5 - Factory Pro, 6 - DynoJunk err... DynoJet.

[md86]

Duh guys , more gas makes it go faster .

[MiDnIgHtKat]

No after market jet kit on the bike he said he put bigger jet's in but i did not think 170 would be that big of a jet for a 600 but i have always worked on dirt bikes and by 125 has a 130 in it thats why i did not think much of that but I will go get smaller jets today and see where to take it from there

[quik89Kat]

No after market jet kit on the bike he said he put bigger jet's in but i did not think 170 would be that big of a jet for a 600 but i have always worked on dirt bikes and by 125 has a 130 in it thats why i did not think much of that but I will go get smaller jets today and see where to take it from there

170 aint big if the bike had a ram air setup it'd be ok ...My zx7 uses 190-200 stock jets with ram air even to get it tuned I went down to 160's but it gets enough air to equal out that much gas...2 stroke dirtbikes use a completely different setup then a 4 stroke street bike

[scottynoface]

2 stroke dirtbikes use a completely different setup then a 4 stroke street bike

biiiiiiiiiiiiiiiiiiig +1 to that

My pre 600 ran right with the full yoshi and uni filter with 120 mains IIRC. 170?!?

[md86]

Yeah , but more fuel means more power , no ? His 170's must run MORE righter than your puny 120's .

[arsenic]

right, that's why you need a 300 tire on the rear

[The CyberPoet]

right, that's why you need a 300 tire on the rear

But only if you can fill it with gasoline and hook it up with a pump to be a spare fuel reservoir for the main tank...

Cheers,
=-= The CyberPoet

__________________________________________________ ________
CyberPoet's Katana Maintence and Upgrade Parts Offerings
The Best Metal Steel Aluminum Motorcycle Tire Valves in the World, plus lots of motorcycle & Katana (GSX600F / GSX750F) specific help files.