how to clean a carb?

[babycleatus]

my entire fuel sys. is completely nasty, some times I have a steady stream of gas flowing from the carb vent tubes. My brother and I went through 2 cans of B12 chemtool and 5000 paper towels. the gas still leaks sometimes. also the fuel selector switch will not close all the way. I bought a can of fuel sys. cleaner but don't know if this will harm a 2-stroke. what is an easy way to completely clean out a carb?

someone told me to boil the carb in anti freeze to remove tarnish and stains?

 

[jdbrusch]

You can buy a heavy duty carb cleaner that auto shops use at the local auto store but this stuff has a smell that will stick with you for days if you get it on your skin.I have found that simple lacquer thinner from the hardware store works very well.You MUST remove all rubber from the carb as the thinner will swell the rubber,orings,needle etc must be removed.Just put the parts in a old coffee can and fill to cover the carb parts,varnish will be desolved overnight.The fuel selector valve has a small rubber grommet(packing) that will leak it it has sat dry for years or possibly from varnish,you may be able to buy just the rubber grommet depending on year of bike,89 to 04 bikes you can buy just the grommet(packing).The tip of the needle being rubber will harden if sat dry or from the varnish also.

 

[rethnal]

How about adjusting your float according to your manual... you do have a manual don't you?

Also... soak your carb overnight and use a good nylon brush the next day to get the residue off. Take a little time with it and don't get discouraged. It ain't no thing!

 

[bradf]

Compressed air is your friend in cleaning carbs. Blow air through all passages after you shoot carb/brake cleaner through. Caution when spraying carb cleaner into a carb port, inevitably it will shoot through a passage that is aimed right at your eyes. The pain is incredible. Protect your eyes!

 

[canyncarvr]

Berryman's works very well.

If you are still leaking fuel, a simple cleaning may well not fix it. You need to burnish the needle seat in the carb.

You know about that, right? If not ask, and I'll type summore...............

 

[JasonWho]

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[TEEEE]

Isn't that like when you pull out a weapon? Oh, no, that's brandish. :rotfl:

Seriously, I'm getting ready to tear into mine for the first time so I'm all ears...

 

[canyncarvr]

Well, Mr.Who...if you checked your manual for this situation (I use a Random House College publication).....;)

burnish: To polish a surface by friction...to make smooth and bright.

This is only intended to resolve a faulty needle/seat seal. It does not resolve a leak resulting from a faulty needle or any other problem (like the petcock 'not closing' all the way as mentioned above).

Take a thin strip of wet-n-dry paper...prolly around 380 or so. 200 will be a bit much, 600 won't get the job done on the first go-round.

Wrap that strip over a q-tip..not 'around' but 'over' so you hold the ends of the paper strip alongside the q-tip shaft. Wet with alcohol, insert into the seat and burnish by rotating the q-tip with slight pressure against the seat.

Repeat at least once with a 'clean' q-tip..maybe move the paper strip slightly to 'show' a new surface to the seat.

You can repeat with 600 if you want. That will make it nice and smooth, but it isn't necessary.

If your needle shows ANY wear or problem (ridge on the viton tip), replace it.

If your needle is brass you can burnish it, too.

Don't get carried away on either end (seat/tip). You don't want to change the angle of the seat, you don't want to remove metal that will result in the whole thing being toast (broke, ruint, no-good, bad, expensive to repair..by buying another carb).

I've 'fixed' a lot of leaking carbs this way.

Those carbs having been abused by storage for too long a time with no fuel stabilizer.

But then, I've also fixed a couple of carbs in NEW machines by replacing the needle. Too much time on the showroom floor maybe?

If you have any question about the needle, replace it. If you don't have a clue why you would even have a question...replace it. ;)

 

[JasonWho]

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[White_Knuckles]

The needle and seat are sold as an assembly - around $14.00. The float arm moves the often rubber tipped needle into the seat to stop fuel flow from the tank. It works like a toilet float ball valve regulating water fill.

They last a couple years and the rubber (or brass) needle tip develops a micro line and they seep fuel when closed. Change out just the needle $7.00 if rubber tipped, change both the needle and seat if brass. Burnishing the brass tip might work but don't attempt a fix for the rubber flavor.

Also check float height before reinstalling.

 

[shr]

If we are talking about a 89 or newer KDX 200 / 220 with the PWK carb, the float valve seat is not replaceable it is part of the main carb body. Also a new float valve needle retails for about $14.00.

 

[D36-108A]

I took my carb apart to clean it and check the float height and needle (it puked gas when not running) and found the service manual doesn't give a method or measurement for the float height. (Hmm, I didn't check the H model supplmement, but...)

 

[BRYDEN1]

Invert the carb with the bowl off and set the level so that the float edge and bowl/carb mating surfaces are parallel.

 

[canyncarvr]

Thanks shr! I was going to say the same thing, full well knowing someone would take issue with the fact of the matter (consider the source and all). No one will argue with you! ;)

re: Invert the carb with the bowl off and set the level so that the float edge and bowl/carb mating surfaces are parallel.

Not merely to nit pick...but you don't mention the needle spring and where it should sit during this process and/or how to make that relationship between the mold line and carb body different.

Point is, quite a few have set their float height and completely ignored the needle pin. Some have bent the floats to effect a fuel level change.

D36: If you are unaware of the process....please ask. Of course...if you are NOT aware...then why would you ask......... oh well....:(

BTW, 'parallel' does get you approximately 16mm (if I recall the number correctly). You're better off with 17 or so (lower level). Also take care when putting the carb back in. Make sure the alignment tab on the carb body correctly matches the notch in the cylinder boot.

Oh...get some allen head screws for your float bowl, a ball-end wrench to wrench 'em and some never/anti-seize on the threads.

imo.......

 

[m0rie]

CC, do you recall what size/pitch allen head screws fit the float bowl?

-Maurice

 

[canyncarvr]

No. Something about 'M5 1.0' sounds familiar, but not for any good enough reason.

***edit***
Note shr's correct sizing notes below!!
**edit**

I took one of mine in and matched it up.

 

[cicone]

CC, do you recall what size/pitch allen head screws fit the float bowl?

-Maurice

Maurice---Often the Buykawasaki part number will tell you the screw specs via the last few digits. For example, the float bowl screw for a 1889 KDX200 is part # 223C0416----and the screw size is 4x16 mm. Hope this helps. I have allens on mine also. Jay :cool: Oh yeah---It doesn't tell you the pitch.

 

[shr]

4 X 0.7 X 16 mm long.

 

[m0rie]

You guys rock! Posts like this are the reason DRN is the place to be.

-Maurice

 

[John Harris]

I like hex head rather than allen head. And easily available from Home Depot or Lowes or your favorite hardware store. Use washers under the heads of either.

 

[D36-108A]

Actually, I was just pointing out that rethnal's comment

How about adjusting your float according to your manual... you do have a manual don't you?

isn't too helpful when it really isn't in the manual.

The rubber needles develop an unseen groove? Crap, I just ordered all the rubber fuel system parts except that one.

FWIW, my carb top gasket (flat rubber ring under the screw top) was bad and let dirt in. Dirt could have stuck open the needle and caused it to leak fuel. Just another possibility for the original poster to consider.

 

[rethnal]

Actually, I was just pointing out that rethnal's comment



isn't too helpful when it really isn't in the manual.

The rubber needles develop an unseen groove? Crap, I just ordered all the rubber fuel system parts except that one.

Well... you could do the ink test... Of course that isn't in the manual.... :think: