Really need help, bike running poorly

[Swynefloo]

Hi everyone, I'm pretty new to bikes and mechanics as a whole, but I know the basics. I've got a '98 and it was sitting for a long while before I bought it. I pull the carbs apart a few times to clean everything out extremely well, put it back together alright as well. The person put on a muzzy exhaust system (very loud, I dislike it) and K&N air filters. When I first got it, it ran extremely poorly, but after cleaning out the carbs and running some seafoam through it, it will actually run. I've played with the jets to try and get the right mixture but I'm still not sure if it's okay.

The bike starts fine, idles fine, and will rev fine while in neutral.

The main problem I'm having is that while I take the bike out, it can start off fine, but whatever gear I'm in, if I give it too much throttle (3-3.5k rpms) it just won't do anything and it'll sound like it's bogging and wants to die. If I hold it in that position after maybe 5 seconds it'll actually take and then shoot up in rpms

What could possbily be causing this? The bike as it stands now is pretty much un-ridable as I can't even get past 30mph.

Thanks for reading, any advice is helpful! Also please keep in mind my finances aren't too in the green, as school has just started for me, so I'll need the cheaper alternative to any fixes you might suggest!

[dirty nasty]

IDK, but I'll gladly trade you my stock airbox and exhaust setup for yours. That's one way to get rid of your problems and you'll have the satisfaction of knowing all your problems are placed on me as I struggle to figure them out. I'm serious.



If you don't accept my offer, first thing I would check is if the carbs are sync'd, mixture screws and idle speed set properly, then the needles. What throttle range does this happen in? Idle, 1/8, 1/4, 1/2, 3/4 or WOT? What ranges does this not happen in?

[Swynefloo]

I'll have to think about that offer haha, but the air box as I understand is a serious pain in the butt.

It idles fine, if I rev it in neutral (or with clutch held in) it'll rev normally. However, as soon as I'm actually in gear and riding, right around 3-3.5k~ rpms it'll just bog and not take. The carbs are synced, I made sure of that when I had them taken apart. The throttle acts normally (for the most part) from idle speed to about 3-3.5k rpms. Keep in mind I can't get past this range of rpms no matter what gear or how hard I pull the throttle, UNLESS I keep the throttle there for about 5-7 seconds and then it'll very slowly pick up the speed

thanks for responding!

[lgk]

what jets were in the carbs?

check your plugs, i think your running lean.

[Swynefloo]

Hey what do you mean by what jets? Stock? And what would cause it to run lean? The jet screw adjustment?

[Jiggles]

You need a bigger set of jets like 104-108 dynojets

[Swynefloo]

Originally Posted by Jiggles

You need a bigger set of jets like 104-108 dynojets

Is that a fact or an opinion?

[alex.s]

dont listen to jiggles. you are describing a rich condition. but being a 98, its very possible its caused by valves clearance needing adjustment. the muzzy and the intake should be making it a bit leaner so my vote is on valves. if that doesn't help try dropping the needle one slot.

[Jiggles]

I thought he said stock jets

[Swynefloo]

Originally Posted by alex.s

dont listen to jiggles. you are describing a rich condition. but being a 98, its very possible its caused by valves clearance needing adjustment. the muzzy and the intake should be making it a bit leaner so my vote is on valves. if that doesn't help try dropping the needle one slot.

I do have the stock jets in still, I'm very new to this still and I hadn't put on the pipes or the air filters.

How do I drop the needles one slot exactly?

[Jiggles]

You're positive the jets are stock and the PO didn't switch them out?

[alex.s]

Originally Posted by Jiggles

I thought he said stock jets

98 refers to the year. current jet size makes no difference. carbs change over time, needle orifices become oblong from normal needle wear letting in more gas. higher flow intake and exhaust should be leaning it a bit. all signs point to valves or float height, captain.

[alex.s]

Originally Posted by Jiggles

You're positive the jets are stock and the PO didn't switch them out?

he said he disassembled the carbs multiple times.

[Jiggles]

Hokay mang. Full exhaust + k&n Intake + stock jets =

Guess anything is possible with a little carb magic

[Swynefloo]

Originally Posted by Jiggles

You're positive the jets are stock and the PO didn't switch them out?

Yeah I'm 98% sure they're stock, the PO wasn't that clever of a dude and said he did no carb work.

[alex.s]

Originally Posted by Jiggles

Hokay mang. Full exhaust + k&n Intake + stock jets =

Guess anything is possible with a little carb magic

muzzy slip on is not full exhaust. and k&n intake is not pod filters

[Jiggles]

Damn

[lgk]

i assumed it was pods because the offer was made to switch pods for a stock box.

[alex.s]

good point. as little-T-bone tells me, i need to take reading comprehension classes.

[Swynefloo]

Originally Posted by alex.s

muzzy slip on is not full exhaust. and k&n intake is not pod filters

they are pods sorry for confusion

[alex.s]

its probably the pods fault. i would get jets and spend some time tuning. there are plenty of guides to how to tune on the board... i think i even wrote a long one that is stickied in the DIY thread


but you probably still need to do the valves.

[Swynefloo]

Originally Posted by alex.s

its probably the pods fault. i would get jets and spend some time tuning. there are plenty of guides to how to tune on the board... i think i even wrote a long one that is stickied in the DIY thread


but you probably still need to do the valves.

damn, the valves was the thing I was trying to avoid doing T.T I don't trust myself with that kind of job, and don't have the money to have someone else do it for me. Rejetting it sounds like the right course of action at the moment, but what stage do I get?

[Jiggles]

Originally Posted by Swynefloo

damn, the valves was the thing I was trying to avoid doing T.T I don't trust myself with that kind of job, and don't have the money to have someone else do it for me. Rejetting it sounds like the right course of action at the moment, but what stage do I get?

Check out the jetting data base in the DIY directory and choose a setup that is close to yours

[Swynefloo]

Originally Posted by Jiggles

Check out the jetting data base in the DIY directory and choose a setup that is close to yours

Oh thank you, didn't know you had one ^^

[Jiggles]

http://www.ninjette.org/forums/showthread.php?t=5586

[Swynefloo]

what would cause the valves to be maladjusted? The bike only has 7k miles on it (I did say it sat for a long time)

[Jiggles]

Originally Posted by Swynefloo

what would cause the valves to be maladjusted? The bike only has 7k miles on it (I did say it sat for a long time)

a pregen needs a valve adjust at 600 miles and 6000 miles. Standard procedure

[Swynefloo]

Originally Posted by Jiggles

a pregen needs a valve adjust at 600 miles and 6000 miles. Standard procedure

Well damn, that's a tall order, what do I do if I screw up? I probably won't have money for a mechanic or other to clean up for me, sigh

[lgk]

just take your time and do it indoors.

follow all the steps and you'll be ok.

[Swynefloo]

Originally Posted by lgk

just take your time and do it indoors.

follow all the steps and you'll be ok.

Well thanks for believing in me

Does the valve adjustment have anything to do with the problem I'm having? Or do I just need to do it anyway because it needs to be done?

[lgk]

Originally Posted by Swynefloo

Well thanks for believing in me

Does the valve adjustment have anything to do with the problem I'm having? Or do I just need to do it anyway because it needs to be done?

if the previous owner did not do it, then you definitely need to.
when the clearances are too tight, the top end will burn up.

[Swynefloo]

Originally Posted by lgk

if the previous owner did not do it, then you definitely need to.
when the clearances are too tight, the top end will burn up.

What does that mean exactly?

[choneofakind]

http://faq.ninja250.org/wiki/Why_do_...be_adjusted%3F


Jet the bike. Check/adjust your valves (not that hard, just time consuming). Sync carbs. Check tuning again.

[lgk]

Originally Posted by Swynefloo

What does that mean exactly?

without proper clearances, the head and valves are damaged in several different ways.

-additional friction between cams and buckets
-valves dont have a good seat and over heat.
-cams seize due to lack of lubrication
-valve seals are damaged due to lateral tresses.
-etc.

these problems can cause a lot of other running issues.

[choneofakind]

It also starts up and runs smoother in the mid/low range with properly adjusted valves. It's worth it to learn how to do the maintenance yourself.

[lgk]

Originally Posted by choneofakind

It's worth it to learn how to do the maintenance yourself.

if your broke its well worth it DIY.

use the saved money to go on some extra rides

[Swynefloo]

Thanks for the help everybody, guess I'll have to get prepared to adjust the valves. Got some reading ahead of me.

[dirty nasty]

I don't think your valves are out of whack at 7k miles. I've just turned over 8k and my bike is still running fine. Gonna check all that **** out over the winter.

Also if you're still considering this trade I'd like to add that my airbox is easy! I cut the battery box off, so getting the carbs off is as simple as removing the battery, 2 bolts, pulling the tray and peeling the airbox off from the carbs. Do you have the full Muzzy system with the header?

[Jiggles]

Originally Posted by dirty nasty

I don't think your valves are out of whack at 7k miles. I've just turned over 8k and my bike is still running fine. Gonna check all that **** out over the winter.

Have to agree with buttcheese on this one, its literally impossible for 2 different bikes to have different valve clearances.

[Lychee]

Originally Posted by Jiggles

Have to agree with buttcheese on this one, its literally impossible for 2 different bikes to have different valve clearances.