new air filter set up

[Jvacustoms]

I have installed a 4 inch k&n style conical universal air filter with a pvc adapter straight off the carburetor. and I am unsure of where to adjust the carburetor to make the bike run right. It takes of smooth until you hit 1/4-3/4 throttle which I think is needle jet settings but I am not sure if i need a new needle jet or just to set that one properly i have already moved the needle jet washer to under the eclip but that doesn't seem enough. can i just add another shim washer below the eclip or do i need to buy an jet kit so that I get the adjustable needle and some other jets to try. also i read that in "Jaime" gz250 power increase that there might be need for a larger than 130 main jet with the air filter and exhaust modifications. It does good in top and bottom throttle points but revs like hell in the middle.
I have tried just adjusting the mixture and that seems to be moot, until i get the needle fixed.

[Gz Rider]

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[Jvacustoms]

Originally Posted by Gz Rider

Since you removed the box that holds the old air cleaner and the oil drip tube that removes oil from that box how will your system handle that oil. Will that oil simply soak your air filter or have you set up somethinge else to handle it.

A pretty standard universal crank case vent on a three way one once side it has the crank case vent and on the other it will have the original hose that holds the oil at the bottom of the airbox. I cant ride her right now until i figure out these carb settings. But that is my plan I will hopefully get some good carb setting answers and then when she runs again i will go get the crankcase vent filter and 3way from napa.

[jonathan180iq]

You are correct in your assumption that the mid range is most affected by the needle. But the main jet also effects all areas to an extent.

I'm not sure of the washer number, but there is one that can be stacked to raise the needle. You may just have to go to Home Depot and play around with different sizes. Try #4, 6, 8 & 10.

I know that once you get down into the guide hole, it gets kind of narrow. You need a washer that will both raise the needle and fit down into the guide hole. (There are two needle designs and I'm assuming you have the kind that allows you to move the clip down, based on your description.)

The biggest jet I've ever heard of anyone using on one of these bikes was a 135. Anything bigger than that has always resulted in the bike running too rich.

What main jet are you running now? 130? Richen it up just a tad, with maybe a 135 and your needle adjustments won't need to be so drastic.
You'll then have to alter the pilot a smidge. But sounds like you know what you are doing enough that it would be better to get it dialed in 100%.

[Jvacustoms]

Originally Posted by jonathan180iq

You are correct in your assumption that the mid range is most affected by the needle. But the main jet also effects all areas to an extent.

I'm not sure of the washer number, but there is one that can be stacked to raise the needle. You may just have to go to Home Depot and play around with different sizes. Try #4, 6, 8 & 10.

I know that once you get down into the guide hole, it gets kind of narrow. You need a washer that will both raise the needle and fit down into the guide hole. (There are two needle designs and I'm assuming you have the kind that allows you to move the clip down, based on your description.)

The biggest jet I've ever heard of anyone using on one of these bikes was a 135. Anything bigger than that has always resulted in the bike running too rich.

What main jet are you running now? 130? Richen it up just a tad, with maybe a 135 and your needle adjustments won't need to be so drastic.
You'll then have to alter the pilot a smidge. But sounds like you know what you are doing enough that it would be better to get it dialed in 100%.

there are no settings on my needle just a washer and an eclip I am hoping to add a washer to adjust it so that I don't have to buy a needle that has the "slots" that you move the eclip from place to place. I have the brass washer that was above the eclip below it now But I am looking to add some more but m unsure of the extent that washers can be added before it will cause malfunction of the needle jet system that is there, i.e. if i add too many washers is it gonna damage the diaphragm or the needle jet guide system ?

[jonathan180iq]

As long as the washers allow the needle to fall down into it's guide all the way, you would have to REALLY stack the crap out of them before they start pushing up against the diaphragm. I mean, it drops down in there a good ways. I think we're talking inches. If you have to adjust that much, might as well buy a new carb

There is no way to know until you experiment. But it shouldn't take too many washers to get a good lift. Even with extreme adjustments to the Ninja 250 carb, 2-3 washers is considered a lot.

[Jvacustoms]

Originally Posted by jonathan180iq

As long as the washers allow the needle to fall down into it's guide all the way, you would have to REALLY stack the crap out of them before they start pushing up against the diaphragm. I mean, it drops down in there a good ways. I think we're talking inches. If you have to adjust that much, might as well buy a new carb

There is no way to know until you experiment. But it shouldn't take too many washers to get a good lift. Even with extreme adjustments to the Ninja 250 carb, 2-3 washers is considered a lot.

Thanks, i happened across the thread where u were talking about mods to your bike and Jaime jumped in. It looks like we think a lot alike, but I am always looking for something to tinker. And ways to save money in the long run. I think that with the washable filter it will save me a little and with the custom made baffling that I made I saved a bit, maybe I will be able to just get what i want outta the bike and that is just to know that i have tried everything that I can think of to increase the overall performance of the bike. for the way I like to ride it. which just might be the opposite of almost every other rider on this forum. but it is the way I am, Stubborn and always looking to learn and try things just to see how they work.

[jonathan180iq]

Yeah, I gave up on the project because after I had all my stuff dialed in, it just wasn't worth the effort to push on the group as a whole.
(If there's one thing I've learned throughout years of tinkering with all of my vehicles, it's that unless there is a readily available and affordable aftermarket bolt-on part, I'm not worried about changing factory performance.) That may make me a little more boring than I was in my younger years, but it is what it is.

If my original quest had made the bike run tons better, you would see me telling everyone who owns one to do all of this stuff first. But it's just a tight work space, a lot of extra trial and error and not as large of a benefit as I wanted to see. Unless you fall in a certain category of tinkerer, as I think you do, then it's not something that everyone should take on. (I really got enthralled when I saw how much throttle was left @ 60mph with the 16T sprocket.)

It's certainly not impossible and you are already about 80% of the way done. Now the dialing-in will just take some piddling. Once you get it set, you never have to worry about it again. But I know that last little bit can be a bit of a drag.

[Jvacustoms]

Originally Posted by jonathan180iq

Yeah, I gave up on the project because after I had all my stuff dialed in, it just wasn't worth the effort to push on the group as a whole.
(If there's one thing I've learned throughout years of tinkering with all of my vehicles, it's that unless there is a readily available and affordable aftermarket bolt-on part, I'm not worried about changing factory performance.) That may make me a little more boring than I was in my younger years, but it is what it is.

If my original quest had made the bike run tons better, you would see me telling everyone who owns one to do all of this stuff first. But it's just a tight work space, a lot of extra trial and error and not as large of a benefit as I wanted to see. Unless you fall in a certain category of tinkerer, as I think you do, then it's not something that everyone should take on. (I really got enthralled when I saw how much throttle was left @ 60mph with the 16T sprocket.)

It's certainly not impossible and you are already about 80% of the way done. Now the dialing-in will just take some piddling. Once you get it set, you never have to worry about it again. But I know that last little bit can be a bit of a drag.

I thought about making it too rich on purpose and throwing a hotter plug in there probably iridium they foul less easy. and just see if i can push a little more power from the bike that way.

I am also very captivated by the remaining throttle but I am going to try to make the motor use that bit even if it hurts my gas mileage to a good degree it will still always be cheaper than my car to drive around...

[jonathan180iq]

Word!

Post back with final results. Expand the body of knowledge.