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Riding in the rain
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253 Posts
Discussion Starter · #1 ·
Hello there,
I was wondering if anyone can give me pointers on how to clean the carbs.
My gf's bike doesn't start properly and I was thinking cleaning the carbs might do the job.

What should my frist step be?

I am sorry but I have absoultely no idea on how to do this.
It would be great if any expert out there can help us out :tredmill

it's a ninja 250 by the way.

<btw, I got my class 6 yesterday!! yay~>
 
G

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first step? take them out.

actually, the first step would be to get a service manual. you can download it from the sticky post in this section. it will give you detailed instructions on maintenance.

but the basics are take them off the bike, drop the bowls, clean the gunk out, clean the jets and seats, clean the slides, put them all back together and put it back in.

or, since you've never done it before, take it to a shop so there are no problems after reassembly. drop by 5th gear for service. they are closeby.
 

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rain? whats that!
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5,834 Posts
What makes you think the carbs are at fault?

What exactly does "not start properly mean?" Does it backfire when you turn it over or something?

Has the bike been sitting for a while? Is the battery charged properly?
 

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Twin A
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8,019 Posts
search there's lots of info here, but before you dig into this make sure it is the carbs and as Doug said: buy a shop manual.
remove the carbs, then take them apart (do not disassemble the carbs from each other!) and spray/soak everything (except the diapraghms, o-rings, anything rubber..) in carb cleaner. using air to clear everything out is helpful. while you have them out check to make sure your pilot screws and floats are adjusted properly. then put them back together.
go slow, work on one at time, and make sure you don't loose anything. if you're not mechanically inclined and you've never touched carbs before.. get someone to do it for you, as if you don't do it right you could end up making one big mess.
 

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Riding in the rain
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253 Posts
Discussion Starter · #5 ·
hmmm sounds like I better leave this job to a professional eh...

yea I tried looking for the manuel but coudln't find it :( Found a 250 ninja manuel for a new model, but don't really know if the same can apply.

Well, the problem with the bike is, it takes a long time for the bike to start. Let's say it sat for a night, then when I try to start the bike (with the choke on), it slowly turns over a bit, and then as I try to apply some gas, it turns over more until eventually starts.
Then when sometimes on the road, and we stop at a intersaction, the bike gradually revs down and dies. Hence my gf has to keep reving the throttle if she feels that the bike is gonna die.

It takes around $200 to get it fix at shops, you guys think it's reasonable?

Thanks for all the help guys!
 
G

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if the bike is turning over slowly, it sounds like the battery is on the way out. might wanna toss it on a charger and check voltages to see if it will hold a charge.

if it is electrical, the best case scenario is a new battery. worst case is the charging system is acting up. if it is just the battery, you can replace it yourself. if it's wiring.. good luck. i hate doing wiring with a passion.
 

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Twin A
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8,019 Posts
the bike gradually revs down and dies.
this by itself sounds like a vacumn leak.
 

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Riding in the rain
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253 Posts
Discussion Starter · #8 ·
Doug, I checked out the charge on the battery, it seems pretty fine (12.09~12.12 when the bike is off) And we just recently changed the battery, so I don't think it is the battery....

Jaybo, what do you mean by a vacumn leak?
does that have to do with carbs?
 

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Twin A
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8,019 Posts
if a vacuum line has been removed, is cracked or plugged then it might just cause what you described. I know on my bike I had an idle problem similar to yours that was fixed as soon as I found and re-installed a vacuum line that I forgot to put on. Vacuum leaks can also be caused if the carbs aren't properly installed in the rubber boots (or if the rubber boots themselves are damaged) that connect the carbs to the intake. when pulling the carbs off check the condition of the boots and the vacuum lines. the vacuum lines are found below the carbs are on the intake and would look something like this.
 

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Riding in the rain
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253 Posts
Discussion Starter · #10 ·
wow, that's great! A picture means more than a thousand words.
I will make sure I check out that problem when I get to the carbs.

Now, this may sound really stupid, but where are the carbs and which part of the bike must I take off in order to locate it?

I apologize for my ignorance...
 

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Twin A
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8,019 Posts
:eek remove the tank and airbox. they should be under that stuff. do yourself a favour if you're serious. 1) find a manual. 2) a friend who knows some of this stuff 3) bring a pad of paper/camera, whatever. take pics and notes of where everything goes before you tear in. leave yourself lots of time. start doing some googling and learn some of the principles.
http://roadstarclinic.com/content/view/56/96/
http://www.dansmc.com/carbs.htm
 

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Riding in the rain
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253 Posts
Discussion Starter · #12 ·
wow, that's awsome.
I will follow your advice and hopefully I can get it to work properly again.

Thanks for all the help Jaybo.
 

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Twin A
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8,019 Posts
you might want to get an opinion from an actual mechanic. it may not be a carb problem. like i said before if you aren't careful and not sure what you're doing you could make it worse. i had to learn the hard way years ago, but that's how you learn.
 

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Registered
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340 Posts
Doug, I checked out the charge on the battery, it seems pretty fine (12.09~12.12 when the bike is off) And we just recently changed the battery, so I don't think it is the battery....

Actually, a good battery will produce a voltage a little higher than that. This could be the reason for the slow turning over. Seems to me that your battery is getting weaker, but still has enough life left in it to start the engine.
Keep an eye on it, and replace it when the problem (the slow turning over) gets worse.
 

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Don't open the carbs up, especially if you're this confused about what's going on.

I'm not trying to be insulting, but there's a lot of other things you should do first before opening up something that complicated, touchy, and capable of being fucked up. I've seen a lot of people crack into the carbs and make a bad situation far worse, and even harder to diagnose.

Start with the routine maintenance schedule, or at least let us know how recent the last services were:

New plugs.
Clean air filter.
Valve adjustment.
Carb synch.
Run a bunch of Techron or your favorite tune up gunk through a couple of tanks of gas.
Visually inspect all vaccum hoses and carb intake boots, and test with WD-40 while the engine is running.

Then get back to us. I've got the service manuals handy in PDF form.

Good luck!
 

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Riding in the rain
Joined
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253 Posts
Discussion Starter · #16 ·
Doug, I checked out the charge on the battery, it seems pretty fine (12.09~12.12 when the bike is off) And we just recently changed the battery, so I don't think it is the battery....


Actually, a good battery will produce a voltage a little higher than that. This could be the reason for the slow turning over. Seems to me that your battery is getting weaker, but still has enough life left in it to start the engine.Keep an eye on it, and replace it when the problem (the slow turning over) gets worse.

O...then perhaps I can charge up the battery and see if it will make a difference. It will be great if this solves my problem.


Don't open the carbs up, especially if you're this confused about what's going on.

I'm not trying to be insulting, but there's a lot of other things you should do first before opening up something that complicated, touchy, and capable of being fucked up. I've seen a lot of people crack into the carbs and make a bad situation far worse, and even harder to diagnose.

Start with the routine maintenance schedule, or at least let us know how recent the last services were:

New plugs.
Clean air filter.
Valve adjustment.
Carb synch.
Run a bunch of Techron or your favorite tune up gunk through a couple of tanks of gas.
Visually inspect all vaccum hoses and carb intake boots, and test with WD-40 while the engine is running.

Then get back to us. I've got the service manuals handy in PDF form.

Good luck!
I don't take it insulting at all. Thanks for the reply. Yes, I must admit that I feel very uneasy opening the carbs and doing the job myself. I would like to perform the less intense maintance job like the ones you mentioned (Clean air filter.
Valve adjustment. Carb synch. Visually inspect all vaccum hoses and carb intake boots, and test with WD-40 while the engine is running.) But I have no idea on how to approach any of these procedures. It will be great if you can send me the pdf to my mail or via msn.

[email protected]

I feel bad bothering you guys but this is the only source I know how to get good expert advice (free) :rockon

Anyways, thanks again
 
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