Engine has trouble revving sounds bogged

[Dab]

This is my first bike my brother gave to me for Christmas. He received it in a trade yada-yada... So it was dropped a few times and ended up sitting awhile. So I cleaned the carbs adjusted the idle mixture screw to 2.5 put new plugs in and just some general maintenance. It idles good starts fine but as soon as I twist the throttle fast the rpms will either drop or go up slowly and have a bogging sound to it. But if I roll slowly on the throttle the bike will climb up steadily with the throttle. The choke isn't engaged throttle cables are fine and I really want to get this on the road ASAP for summer

[DaBlue1]

Originally Posted by Dab

.... It idles good starts fine but as soon as I twist the throttle fast the rpms will either drop or go up slowly and have a bogging sound to it. But if I roll slowly on the throttle the bike will climb up steadily with the throttle.

Jets are either too big or too small or still dirty.

Lean or Rich

[Dab]

It's definitely not dirty I ultrasonic cleaned the carbs just wondering if it would be the air mixture screw on the bottom of each carb that's what my buddy tells me but doesn't make sense

[DaBlue1]

Originally Posted by Dab

It's definitely not dirty I ultrasonic cleaned the carbs just wondering if it would be the air mixture screw on the bottom of each carb that's what my buddy tells me but doesn't make sense

Even though you may have cleaned it ultrasonically, (time than not), the individual jets need to to be removed and cleaned with fine wire.

Your idle mixture screws may only need a minimum of adjustments. Make sure you have the jets perfectly clean first, then fine tune the idle mixture screws. If not you may be chasing this problem unnecessarily.

[Dab]

Yep I cleaned the jets with a guitar string and was careful not to scratch the passage ways. So that just leaves tinkering with the idle adjustment screws to find the balance between rich and lean?

[quarterliter]

How's the air filter look? Try removing it and see if it changes

[Dab]

Originally Posted by quarterliter

How's the air filter look? Try removing it and see if it changes

I have and it doesn't make much difference

[alex.s]

have you tried a sacrificial goat? maybe if you change to waterless coolant it would be different. maybe start praying now and by winter something will be different? you could always make the bike a cake and some wine and cheese and ask it really nicely and remind it to just relax and maybe push a little bit to make it easier. did you check your muffler bearings? i've had really good results when i switched to carbon nanotube graphite magnesium titanium 5-star spark plugs. maybe it is your steering tube bearings giving so much slop that the front wheel is buckling under and its the drag from the front wheel that is slowing the engine down? i think maybe you should also switch to clipons and rearsets. it definitely makes you feel like you're going faster.

[Dab]

Originally Posted by alex.s

have you tried a sacrificial goat? maybe if you change to waterless coolant it would be different. maybe start praying now and by winter something will be different? you could always make the bike a cake and some wine and cheese and ask it really nicely and remind it to just relax and maybe push a little bit to make it easier. did you check your muffler bearings? i've had really good results when i switched to carbon nanotube graphite magnesium titanium 5-star spark plugs. maybe it is your steering tube bearings giving so much slop that the front wheel is buckling under and its the drag from the front wheel that is slowing the engine down? i think maybe you should also switch to clipons and rearsets. it definitely makes you feel like you're going faster.

Ooh good one that really helped... Stop wasting my time people are trying to get help here

[alex.s]

stop wasting your time? sorry, i had not realized you were paying someone for a service here. i guess i wont post in your thread since you don't want me to

[quarterliter]

How old is the fuel? How much is in the tank?

[Dab]

Originally Posted by quarterliter

How old is the fuel? How much is in the tank?

Half a tank of 89 octane not even two weeks old

Btw thanks for helping out a newbie

[DaBlue1]

Are you whacking on the throttle while the engine is cold?
Are you using the choke to help start and warm it up?
What are the sizes of your jets/
Is the bike completely stock?
Any modifications to the intake/exhaust?

How Constant Velocity Carburetors Work(see pages 14-20)

[Dab]

Originally Posted by DaBlue1

Are you whacking on the throttle while the engine is cold?
Are you using the choke to help start and warm it up?
What are the sizes of your jets/
Is the bike completely stock?
Any modifications to the intake/exhaust?

How Constant Velocity Carburetors Work(see pages 14-20)

I start my bike without choke ride it around the block a couple times to warm it up, but still can't whack the throttle when it's warm

[Dab]

And it's completely stock one exhaust is pretty banged up but that shouldn't effect the performance thaaaat much

[Motofool]

Originally Posted by Dab

.....It's definitely not dirty I ultrasonic cleaned the carbs just wondering if it would be the air mixture screw on the bottom of each carb that's what my buddy tells me but doesn't make sense............ Btw thanks for helping out a newbie

If you did not remove those air mixture screws, your carbs are still dirty.

Please, read this:
http://n4mwd.blogspot.com/2013/10/se...-passages.html

If you did, then for some reason your diaphragms are not moving those needles up when you open the throttle or the level of fuel in the bowls is too low.

http://faq.ninja250.org/wiki/How_do_...n_correctly%3F

http://faq.ninja250.org/wiki/How_do_..._the_floats%3F

You are welcome

[Dab]

My idle mix screws don't have that cap on them anymore I'm guessing they were played with before. Would that have anything to do with it? don't see how idle could effect throttling up

[DaBlue1]

Originally Posted by Dab

My idle mix screws don't have that cap on them anymore I'm guessing they were played with before. Would that have anything to do with it? don't see how idle could effect throttling up

The pilot jets supply most of the fuel at low throttle openings.
The (idle mixture) pilot screws and pilot air jets affect the carb @ idle - 1/4 throttle position.

After 1/4 throttle (or approx 3k rpm) the slides begin to lift.

Motorcycle Carburetor Theory 101

[DaBlue1]

CV carburetor
http://www.youtube.com/watch?v=wyspAHrMbb8

[Dab]

Ok I'll pull the carbs again clean them, set everything to spec, put new lines on everything and hope for the best will update the status when I'm done

[quarterliter]

See what size the mains are. Also make sure there are no tears in the rubber part of the slide. Do all the vacuum lines look good?

[Kscreations08]

Originally Posted by alex.s

i've had really good results when i switched to carbon nanotube graphite magnesium titanium 5-star spark plugs.

Sounds fancy. Don't imagine those came cheap. Hey Unregistered, can we get a dyno reading with these spark plugs compared to stock?

To the OP, as crazy as it sounds, the cheese and wine thing really does work. You just have to woo her into doing what you want. A roofie in the gas tank might help persuade her

[Dab]

Bikes running a lot better have idle screws at 3 1/4 turns out and it's running great don't know what was wrong but its fixed. Now I just need to fix the fuel tank will a steel tank be able to be brazed closed with silver solder?