Carburetor removal and cleaning.

[Løckøut]

So, I've goten o the airbox. I've removed te screws and olts all the way down, and moved back the under tail and pushed the air box back. I have instructions refeing to he 'air box springs'. Are these the small coils around he connector between the airbox and carb? I don't wan to mess anything up and this is my first bike , ought on saturday; and my first bike DIY besides oil change. Thanks for input; from here on out as far as removing carb info I might need, tools to clean[ I have fuel reatment, full carb solution tub w/ basket, and aerosol carb cleaner. Standard tool kit] I would be deeply appreciaive. Thanks everyone.

[FvnnyL3tt3r1ng]

Originally Posted by Løckøut

So, I've goten o the airbox. I've removed te screws and olts all the way down, and moved back the under tail and pushed the air box back. I have instructions refeing to he 'air box springs'. Are these the small coils around he connector between the airbox and carb? I don't wan to mess anything up and this is my first bike , ought on saturday; and my first bike DIY besides oil change. Thanks for input; from here on out as far as removing carb info I might need, tools to clean[ I have fuel reatment, full carb solution tub w/ basket, and aerosol carb cleaner. Standard tool kit] I would be deeply appreciaive. Thanks everyone.

Yeah just pull those springs back. Make sure you disconnect your choke cable and your vacuum and fuel lines located on the fuel tap.

The only thing you can really mess up is by damaging your diaphragms inside the carburater but worry about that after you pull the carbs out.

[FvnnyL3tt3r1ng]

I use a guitar string and a toothbrush to clean my carbs btw, those you didn't list but who knows maybe the basket and solution will do the trick.

[Løckøut]

Thanks for the input; ive removed the carbs successfully. I see buildup by the jets, maybe this is what was causing low idle and throttle hesitation... I couldn't get over 6k rpms, it was a fight to hold 40mph.

I'm about to start pulling the hoses of and prepping for the spray and dip now. Any other advice or pointers in the process would be great. Thanks again.

Edit: The problem wich caused me to go after the carbs was seemingly out of nowhere, I was beginning to get hesitation in my throttle. I was geting onto the highway, and the bike was not reponding to my throttle, and instead lagged and made almost a back-pressure sound if given more throttle than it was applying.. It held 55 until I got off the highway, then it would hold about 45 for a couple miles, then 40, eventually it would only hold 35 once I got home. Does this sound like a valve issue?

[Løckøut]

Something I noticed wile removing the carb; i did not have to move back the springs around the intake boot connecting to the carbs. It slid off oddly easy. Maybe this was the problem in the first place?

[Yarhj]

It sounds like you removed all the fender bolts, enabling you to push your airbox farther back, right? If that's the case, the carbs should just slip (relatively) easily out of the airbox boots, independently of where those springs are. That's how it works on my bike, anyway, though maybe my springs are just old and tired. I get the feeling the springs are more to keep the carbs from slowly wriggling free from the airbox due to vibration than to prevent the carbs from being removed at all.

While you have everything taken apart, definitely do the battery box mod -- it'll make your life so much simpler if you ever need to deal with the carburetors again. If the airbox is still on the bike, do N4's battery box mod instead, since it saves you the trouble of removing the airbox.

There's a wealth of info on the carb cleaning process at the ninja250 wiki. Even with the chemical dip, you may still need a small copper wire (14-18 gauge) to clean out the passageways on the jets.

Your issue doesn't sound all that carb-related to me, to be honest, but I'm no expert. What RPMs was the bike at when it was struggling? If your main jet was clogged you should have trouble getting the bike above 5000 RPM. I have trouble envisioning a scenario where the main jet would clog, but the pilot jet would still be clear enough for you to start the bike and ride off (barring actual chunks of debris floating around in your gas). Was the bike sputtering and threatening to stall above 5000RPM, or was it having trouble maintaining speed independent of engine speed? Has the bike sat for an extended period of time? How many miles are on it, and when were the valves last checked?

[Løckøut]

The bike has 2400 miles on it. I haven't checked the valves ever and didnt ask the previous owner. Yes, it tried to give out around 5-6k rpms. I've only had it since saturday. It runs and drives without threatening to stall, but it definitely had a gradual one-day episode to get to the state it is in. I have cleaned the carbs and am starting to put it back together.

To reiterate , it does not stall, it simply gives up it's power after 5k. It will not pull uphill, and fights to hold higher rpms on the downhill even. This is my daily commuter and i've been really stressed about this. It looks like getting to work Monday will be an issue... lets hope this carb cleaning had done the trick.

Any other possibilities that this could be related to, please inform me. This is my first bike.

[baxtc1]

I trust you have cleaned/replaced your air filter?

[Løckøut]

Originally Posted by baxtc1

I trust you have cleaned/replaced your air filter?

negative. Havent had the funds, honestly. I figured the carb was the problem due to another rider's thread, its my mistake for generalizing symptoms for the same diagnosis. Anyways, how would I go about getting to my air filter?

[Løckøut]

Well, she's running like she was before. I guess this was the issue? If it comes back I'll know tonight, I'm going out for a saturday night ride. Thanks for the help everyone.

[n4mwd]

Without the battery box mod, you need to take 4 additional bolts out to remove the carb. The problem is that the ones behind the rear fender are a bear to get out - and re-install. The only problem with the battery box mod is that the bike is no longer OEM and the airbox has no concrete attachment to the bike.

From your description, it sounds like the main jets were clogged. Did you clean the pilot jets too or just the main jets?

How did it do on your ride?

EDIT: Its not the valves.

[Løckøut]

Originally Posted by n4mwd

Without the battery box mod, you need to take 4 additional bolts out to remove the carb. The problem is that the ones behind the rear fender are a bear to get out - and re-install. The only problem with the battery box mod is that the bike is no longer OEM and the airbox has no concrete attachment to the bike.

From your description, it sounds like the main jets were clogged. Did you clean the pilot jets too or just the main jets?

How did it do on your ride?

EDIT: Its not the valves.

I've ridden it about four times since the fix, no issues. I sprayed down every opening and began the carb fuel treatment. I'm not too keen which ones are the main jets and pilot jets; the four that are on the botom of the two big main openings, I put the straw of the carb spray in them and sprayed all four. Then both the main openings from boh sides; and all the small holes. [I found out what the reading meant by 'skin iritation' ] but I prety much drenched it in the stuff, I almost removed all the hoses and dipped the entire carb into solution, but was too unmotivated/drunk to g through with removing all the hoses, as I was a bit discouraged from Yarhj's post. But, it turned out that the carb just needed a good cleaning. Alot of orange/brown came out of the jets.

[choneofakind]

Originally Posted by n4mwd

Without the battery box mod, you need to take 4 additional bolts out to remove the carb. The problem is that the ones behind the rear fender are a bear to get out - and re-install. The only problem with the battery box mod is that the bike is no longer OEM and the airbox has no concrete attachment to the bike.

No, you can get them out without loosening the fender. Doesn't take that long, just kinda have to fight with them. Doing the mod does make it much easier though.

[n4mwd]

Originally Posted by Løckøut

I've ridden it about four times since the fix, no issues. I sprayed down every opening and began the carb fuel treatment. I'm not too keen which ones are the main jets and pilot jets; the four that are on the botom of the two big main openings, I put the straw of the carb spray in them and sprayed all four. Then both the main openings from boh sides; and all the small holes. [I found out what the reading meant by 'skin iritation' ] but I prety much drenched it in the stuff, I almost removed all the hoses and dipped the entire carb into solution, but was too unmotivated/drunk to g through with removing all the hoses, as I was a bit discouraged from Yarhj's post. But, it turned out that the carb just needed a good cleaning. Alot of orange/brown came out of the jets.

Just spraying the jets don't really clean them. It just blows the clog further into the carburetor. If you have problems again, you should remove the jets, all four, and clean them separately and then re-install them. There are lots of little pinholes in them that need cleaning out usually. Also, when you dunked your carb, I hope you removed the diaphragms. They are sensitive to cleaning solutions and it can cause them to rot out.

[Løckøut]

Well, I guess I'm resurrecting this thread it seems. Around 900 miles later, my cab is stuck again [ in that I can't get over 40mph, the issue I had last time.]

I've been riding faster and more aggressive since my last enries, now that I'm used to the bike. Could this be from running it harder? Is this nomal to get another clog so early? Or maybe, like what was said last time, I might not have removed the clog, just moved it inside the carb from not fully pulling it apart?

Some weigh-ins would be appreciated.

[n4mwd]

It doesn't really sound like you correctly cleaned your carbs the first time.

Did you remove the jets, all 4, and blow out the gunk from the pores?

Was there any brown stuff in the bottom of the bowls?

Did you remove and clean the fuel filter that is at the inlet to the carburetor?

Here are the passages in addition to the jets that need cleaning:
Secret Passages


Here is a video that shows the easy way to remove the carbs.

Link to original page on YouTube.

[Løckøut]

Thanks N4MWD.

I got the gaskets off of the carb, sprayed inside where the floats are and noticed I dont have the tools to fully pull it apart. -- I did find a green gooey substance inside one of the orifices, and pulled that out. I sprayed the whole carb down since there was no real build up anywhere visible, and went further into detail spraying. Once I got everything put back on and took it for a test drive, the idle seems to be floating; if I give it gas and release in neutral, it'll slowly return to the idle set, in small laggy stages [not like it's stuck, but slowly decreasing into intervals of 500rpms.] Any ideas what this might be?

On the plus side, the bike sounds amazing now. Very smooth acceleration, and you can hear he engine clearly... oh, also, I found a small hole on the bottom rear corner of the airbox about the side of a sunflower kernel. Maybe this has something to do with it?

[choneofakind]

No, that's just a drain hole for the intake side of the filter. They all have those

[n4mwd]

One thing is that you need to remove the diaphragms before spraying any solvents in there. I assume that you went by the numerous DIYs out there for carb cleaning. Some people say that the carb solvent cleaners can damage the diaphragms. I always took them out. But in any case, your carbs don't sound like the diaphragms are bad. I don't think you would have good acceleration if they were.

[Løckøut]

Well, I went out to start it this morning and it wasn't holding flame; so I assumed the carbs had dropped he gasoline inside of them overnight. This seems to be the case, as once I got it started [wit much choke and throttle], the idle jumped and gradually built. Then, once I got it evened back out and took it for a ride, and got back, I'm noticing gasoline around the edge of, and beading at the farthest left corner of the gasket. The left gasket is not holdign the gasoline inside of it; maybe I did not tighten it enough when replacing it, because the video cautioned me on not tightening it too much lest I strip the screw, maybe I just chicken-footed it to avoid damaging the screws, as one tried to strip when I pulled them off. I will remove the carb and tighten the screws further specifically on this side, as the right carb is not showing such incontainance, and get back to you guys.

Another symptom is, if the idle is adjusted above 3k, it will stay there when slowing down; however if I have it adjusted to 1.8-2 where I prefer it, it will stay at 3k when I slow down from a roll, and slowly drop to the idle I adjust it to, then slowly drop even further, to the point it seems to want to lose pressure and die. So I assume it's not able to hold the gasoline being delivered; at speed and accelerating seem to not be affected.

[Løckøut]

Found what I think is the issue. The right carb/valve boot wasn't tightened, and makes alot of sense to the issue's smptoms. I still pulled the carb off and tightened all the screws, reinstalled and took for a test drive. Everything is running fine.

On a side note... I dont know about all of you, but sitin on the frame with no side fairings and seat on the bike is hella comfortable. Are there any seat mods to make it this low and in this stance [crotch behind the battery]?

[n4mwd]

You need to test your petcock. It shouldn't take more than a few minutes. See my blog below for how.

You need to check your oil level to make sure it didn't get mixed with gas. Basically, if its a lot higher than you expected, like over the glass, then its contaminated with gas and needs to be changed before your bearings are damaged.

The loose boot can cause the bike to run funny so that was probably part of your problem.

When starting a flooded engine, choke off, throttle WOT.