Stage 1 jet kit for a 2008?

[Fissel]

Surprised to find DynoJet doesn't appear to offer a jet kit for the 2008-10 Ninja 250, only a stage two kit. What is everyone using?
Just picked this bike up, has sat for a full four years and the gas was disgusting and carbs were pretty dirty. While in there I figured I would install a stage one kit to compensate for the (I assume) terrible factory jetting. I plan to leave this bike 100% stock otherwise. Carbs were a little tricky to get off so I just assume do it once.
Any help is much appreciated-
Fissel

[Triple Jim]

Each person has his own definition of what "stage 1" means. What is your goal? I'd do a thorough carb cleaning and run it enough to find out if it really needs any changes. My pregen runs pretty darned well stock, and gets mid-upper 60s for MPG. I have no plans to mess with that.

Welcome to the board, it's good to meet you.

[Fissel]

Originally Posted by Triple Jim

Each person has his own definition of what "stage 1" means. What is your goal? I'd do a thorough carb cleaning and run it enough to find out if it really needs any changes. My pregen runs pretty darned well stock, and gets mid-upper 60s for MPG. I have no plans to mess with that.

Welcome to the board, it's good to meet you.

In my experience, modern bikes are generally jetted quite lean to satisfy the folks at the EPA. A stage 1 jet kit basically corrects this, and that's all I was interested in doing.
You saying the stock setup "runs pretty darned well" gives me hope.

Do most people with the stock exhaust/airbox run stock jetting? Again, Kawasaki didn't make it easy to get the carbs off so I just assume not have to do this again anytime soon.

[Lazarus]

I believe the stock main and pilot for the new gens are 98 and 38 respectively. I have the typical bolts on and only have 100 mains and 40 pilots. I'm actually thinking about going back to 38 pilots.

Every bike is different but I figured if I have all these mods and have only moved up 1 main jet size and 1 pilot size you may run to rich if you mess with the jetting. Have you tried adding some small washers to the carb needles? That helps with flat spots in the higher revs (7.5k-12.5k)

*disclaimer: my bike could very well be running lean but the way she runs and the color of the plugs says shes okay* just figured I'd throw my .02 in for reference. Best of luck!

[cbinker]

Originally Posted by Fissel

In my experience, modern bikes are generally jetted quite lean to satisfy the folks at the EPA. A stage 1 jet kit basically corrects this, and that's all I was interested in doing.
You saying the stock setup "runs pretty darned well" gives me hope.

Do most people with the stock exhaust/airbox run stock jetting? Again, Kawasaki didn't make it easy to get the carbs off so I just assume not have to do this again anytime soon.

if you are going to use only stock, you will still have to pop the caps off the mixture screws on the bottom of the carburetor.

https://www.ninjette.org/forums/showthread.php?t=10246

[Fissel]

Originally Posted by cbinker

if you are going to use only stock, you will still have to pop the caps off the mixture screws on the bottom of the carburetor.

https://www.ninjette.org/forums/showthread.php?t=10246

Thanks for the heads up, but I'm well aware- caps are already removed.

[Fissel]

Originally Posted by Lazarus

I believe the stock main and pilot for the new gens are 98 and 38 respectively. I have the typical bolts on and only have 100 mains and 40 pilots. I'm actually thinking about going back to 38 pilots.

Every bike is different but I figured if I have all these mods and have only moved up 1 main jet size and 1 pilot size you may run to rich if you mess with the jetting. Have you tried adding some small washers to the carb needles? That helps with flat spots in the higher revs (7.5k-12.5k)

*disclaimer: my bike could very well be running lean but the way she runs and the color of the plugs says shes okay* just figured I'd throw my .02 in for reference. Best of luck!

Thanks for the intel. Maybe I'll just leave it stock. Sounds like it isn't that far off. A couple of other modern carb bikes I've had (especially the Triumph Thruxton 900) ran massively better with some small changes from original.

[Lazarus]

No problem. Let us know what you decide to do!

[Dave Wolfe]

Stock its lean at idle/mid range and rich on top end. Biggest improvement for street riding is adjusting idle mixture. If you rev the piss out of it regularly, maybe go down a size on the mainjet.

[Fissel]

Originally Posted by Dave Wolfe

Stock its lean at idle/mid range and rich on top end. Biggest improvement for street riding is adjusting carb needles. If you rev the piss out of it regularly, maybe go to a size on the mainjet.

Lean at idle & the bottom end of mid-range I should be able to fix with the mixture screws. No plan to "rev the piss out of it regularly" as I've got quicker bikes if I feel the need.
Thanks for the feedback.

[Dave Wolfe]

Originally Posted by Fissel

Lean at idle & the bottom end of mid-range I should be able to fix with the mixture screws. No plan to "rev the piss out of it regularly" as I've got quicker bikes if I feel the need.
Thanks for the feedback.

Oopss - i meant biggest improvement for street riding is adjusting idle mixture, not so much the needles. It transforms it from being anemic off idle to actually having a little pep. If you need to throw a washer under the needles to tune the midrange you can do that later with the carbs still on the bike.

[Triple Jim]

Don't overlook the airbox-battery box separation mod. I love the improvements it gives.

[Ram Jet]

Originally Posted by Fissel

Surprised to find DynoJet doesn't appear to offer a jet kit for the 2008-10 Ninja 250, only a stage two kit. What is everyone using?
Just picked this bike up, has sat for a full four years and the gas was disgusting and carbs were pretty dirty. While in there I figured I would install a stage one kit to compensate for the (I assume) terrible factory jetting. I plan to leave this bike 100% stock otherwise. Carbs were a little tricky to get off so I just assume do it once.
Any help is much appreciated-
Fissel

On my 2007 I have simply increased the main jet size from a 105 to a 110 and it runs fine. I have about 500 miles on the 110 main jets and I'm going to pull the plugs soon to see if I like the color. I put Yoshimura mufflers on at the same time I increased the main jet size. I would have increased the main jet size even with the stock mufflers as the plugs were running way too white for my comfort levels. I have shims for the jet needles but I don't plan on using them. You may just want to go to larger mains and you'll be OK. I'll bet dollars to donuts that your stock main jets are too lean (thank you EPA and California). What a-lot of people don't understand is that an increase in main jet size will enrichen the fuel mixture from 1/4 throttle to full - it doesn't just affect full throttle operation.

Bill

[Ram Jet]

Originally Posted by Dave Wolfe

Oopss - i meant biggest improvement for street riding is adjusting idle mixture, not so much the needles. It transforms it from being anemic off idle to actually having a little pep. If you need to throw a washer under the needles to tune the midrange you can do that later with the carbs still on the bike.

I can't get to my jet needles with the carbs still on the bike. I can't get at all the screws. No matter, I decided my bike doesn't need shimming.

Bill

[Ralgha]

Originally Posted by Fissel

Lean at idle & the bottom end of mid-range I should be able to fix with the mixture screws. No plan to "rev the piss out of it regularly" as I've got quicker bikes if I feel the need.
Thanks for the feedback.

Revving the piss out of it is what gets it off! The party starts around 9,000 RPM in the Ninja.

[KikRox]

Originally Posted by Ralgha

Revving the piss out of it is what gets it off! The party starts around 9,000 RPM in the Ninja.

LMFAO!! So true... It doesnt have much torque but it has rpm and they will take the abuse almost submissively like "go ahead beat on me, it turns me on".

[Triple Jim]

It's not really much abuse when the little pistons only move about 1-5/8 inches.

[Ram Jet]

Originally Posted by KikRox

LMFAO!! So true... It doesnt have much torque but it has rpm and they will take the abuse almost submissively like "go ahead beat on me, it turns me on".

Baloney. That little engine has as much torque as my 500cc Honda single and I'm running 15/42 sprockets. Fine engineering I'd say, 31 H.P. at 12 K and pulls like a little bull from 5 K up.

Bill

[Ram Jet]

Originally Posted by Triple Jim

It's not really much abuse when the little pistons only move about 1-5/8 inches.

Yeah, but it's that sudden stop at the top and bottom of the stroke that's a bitch!

[Triple Jim]

As an engineering boss I once had use to say, "harmonic motion." There are no sudden stops because of harmonic motion.

[Ram Jet]

Originally Posted by Triple Jim

As an engineering boss I once had use to say, "harmonic motion." There are no sudden stops because of harmonic motion.

Yes, I know what you mean. If I get on my bike at point A and travel to point B and back to A without stopping, I approach point B slowing down and accelerate away from point B. It's still a bitch if you're a piston or connecting rod. The force is so strong it actually stretches the con rod a few millionths of an inch.

Bill