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drz400s jetting help

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Ok so I just bought the bike a week ago, it came with a full yoshimura rs-2 exhaust, 3x3 mod, and a twin air filter.

the bike was backfiring a decent amount so I pulled the spark plug to check it and it was a little lean based off that.

so I then ordered a dynojet kit and not paying attention got a stage one kit, so I then sourced a 160 main and 25 pilot locally to make up my jet kit.

pulled the carb apart and dun dun it's jetted already with:

145 main

25 pilot

different needle, looks like the new dynojet with 6 spaces

and the air fuel screw replaced

so what I did is put in all the new stuff:

160 main

25 pilot

New needle, on the 3rd from the top

air fuel screw out 3 turns

bike well only start full choke, stumbles on half and won't start or run with out the choke. off I try to give it gas it dies no matter where the choke is.

the other thing off the 160 main has a bigger head on it but it fit no problem in the little plastic clip thing.

any help, oh I'm at sea level.....0 altitude.

thanks

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Ok so I just bought the bike a week ago, it came with a full yoshimura rs-2 exhaust, 3x3 mod, and a twin air filter.

the bike was backfiring a decent amount so I pulled the spark plug to check it and it was a little lean based off that.

so I then ordered a dynojet kit and not paying attention got a stage one kit, so I then sourced a 160 main and 25 pilot locally to make up my jet kit.

pulled the carb apart and dun dun it's jetted already with:

145 main

25 pilot

different needle, looks like the new dynojet with 6 spaces

and the air fuel screw replaced

so what I did is put in all the new stuff:

160 main

25 pilot

New needle, on the 3rd from the top

air fuel screw out 3 turns

bike well only start full choke, stumbles on half and won't start or run with out the choke. off I try to give it gas it dies no matter where the choke is.

the other thing off the 160 main has a bigger head on it but it fit no problem in the little plastic clip thing.

any help, oh I'm at sea level.....0 altitude.

thanks

Does it start and run without choke once it is warm?

If your bike will start and run from cold without choke, it is too rich on the pilot circuit..

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I guess it helps to connect the vacuum line to the carb from the petcock too. It's way better now, haven't rode it yet because now I'm on to my next mission, leaking oil from the front sprocket.

Thanks

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I guess it helps to connect the vacuum line to the carb from the petcock too. It's way better now, haven't rode it yet because now I'm on to my next mission, leaking oil from the front sprocket.

Thanks

I am pretty sure there was a kit in the TT shop for that but I can not find it.

Not a hard job to fix, someone more computer savvy will probably post a link.

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I've got a new 2012 S as well....yosh RS2, 3x3 and jet kit.....i'm running a 155 with a 22.5 with extended screw...I had to make my 3x3 like a 4x5 to get rid of a wide open throttle bog with the 155, you'll probably be in the same boat

 

 

pulls like a champ now though....2nd gear power wheelies not and issue

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Ok so I just bought the bike a week ago, it came with a full yoshimura rs-2 exhaust, 3x3 mod, and a twin air filter.

the bike was backfiring a decent amount so I pulled the spark plug to check it and it was a little lean based off that.

so I then ordered a dynojet kit and not paying attention got a stage one kit, so I then sourced a 160 main and 25 pilot locally to make up my jet kit.

pulled the carb apart and dun dun it's jetted already with:

145 main

25 pilot

different needle, looks like the new dynojet with 6 spaces

and the air fuel screw replaced

so what I did is put in all the new stuff:

160 main

25 pilot

New needle, on the 3rd from the top

air fuel screw out 3 turns

bike well only start full choke, stumbles on half and won't start or run with out the choke. off I try to give it gas it dies no matter where the choke is.

the other thing off the 160 main has a bigger head on it but it fit no problem in the little plastic clip thing.

any help, oh I'm at sea level.....0 altitude.

thanks

 

The stage 1 needle can be still used with the 3x3 mod, but it's not the best...

Use .... 

 

142.5 main jet with open pipe

Needle on clip #4

25 pilot jet with stock fuel screw or 22.5 pj with extended screw

2.75 turns

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So seeing as it was lean with a 145 main, 25 pilot, and dyno jet needle, you're saying pit in a 142.5 main

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So seeing as it was lean with a 145 main, 25 pilot, and dyno jet needle, you're saying pit in a 142.5 main

 

You are only guessing it's lean....poping on decel is normal

with stage 1 dynojet kit the settings I listed will be fine....

In layman's terms ,,the st 1 needle has a narrow profile towards the bottom, so it blocks the main jet less, enabling the use of a smaller main jet....

 

The pilot circuit may have some blockage causing your issues

Edited by Craigo 485sm

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Ok so let's say I have the dynojet kit, and a 160 main, 145 main, and 2 different 25 pilot jets and the carb has the extended air/fuel screw, not sure which one, it's got a round head with one flat spot in it.

I do not have the stock pilot jet or stick fuel screw, where to go from there.

The bike cruises fine at 45mph and up but in lower gears and speeds it feels like it's missing or choking, and throttle response other than full throttle it's hesitant and anything but smooth.

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