carb questions

[dgjks6 6]

My 312-8 sometimes runs "roungh" - it surges a little - even at full throttle. My plan is to check the carb, but I have a question. Now that I have been inside one - I cleaned a tecumseh off a puch mower - do I just clean it - meaning take it off, take the float out, etc and clean the inside really well - or should I ficure out how to do a rebuild of it - meaning take all of the small pieces out. I know this seems basic - but I am still learning. I could take the carb off, take the bowl off, clean it and reassemble it in a short time, or I could try to rebuild the whole thing.

What do you guys with more experience think?

Greg

[BairleaFarm 339]

Id pull it and rebuild it. It doesnt take long ang you know its done.

[HorseFixer 2,012]

Well as duramaxdavid stated at least you will know its done by rebuilding.

This is what I do when I rebuild a carb,

The first thing I do is check the throttle shaft for slop if its wobbly and has alot of play then that is most likely your problem. if it feels pretty tight then read on. if not you will need a carb rebuild kit and throttle shaft and bushing and thats a bit more tough.

1st make sure you have all the parts you will need (gaskets, carb to engine and engine to air cleaner) float needle and seat and bowl gaskets. before you get started remove the high speed and idle adjustment needles and make sure they are not pitted. If they are you may need those also. at this point remove the carb.

STOP! at this point if you are replacing needles and throttle shaft and a carb kit you may be cheaper in finding a good used or new carb weigh the cost of the parts VS new or good used.. If rebuilding is cheaper continue.

Dissasemble the carb by removing float bowl. remove pin in float, remove float and then remove the needle and seat, remove high speed and idle jets. take some carb cleaner and spray off all the loose crud off the carb ( I suggest this as not to spoil your carb soak) the best thing to do after all parts are removed is get a gallon can of solder seal or rector seal carb dunk cleaner or simular. try and get the kind with a little parts basket Auto zone sells these types Only soak degreased carbs in this solvent to make it last it will last along time if you do!

Then take the whole famdamily and soak all the parts try and give a little agitation every so often usually takes about 20 min to half hr. remove all the parts and spray off with carb cleaner then blow off with air hose. I Then reassemble and set float level per specs. I usually then polish the brass needles with some polish like brasso with a soft cloth I then examine the high speed jet and make sure all the port holes are clean and can blow air thru all of them (very important). after reassembly check your starting points for high and Idle adjustments. Make sure you install a new fuel filter also. That should get yer carb in top shape! Good luck!

Duke

[linen beige 14]

I'll second Duke's post, and add a couple things. If it needs throttle shaft bushings and you're not experienced with shop equipment or don't have a good drill press, take it to a local machine shop and have them drill out the holes for you. It is CRITICAL that these holes be perfectly centered. Not hard to do once you figure out how , but tricky if you can't find the original centerpoint. Hopefully the machine shop will let you watch how they center the drill. Kohler's downloadable manual covers it in detail.

The parts of a carb are mostly made from very soft metals. Good tools and techniques are a must for disassembly/ reassembly without damaging these parts. Gunsmith's screwdrivers and gun cleaning brushes are very useful, as are old toothbrushes. The softer nylon brushes won't damage the metal, but some solvents will eat up the brushes. Brass ones can be used with caution. DO NOT use the stainless brushes! If you find screw heads with distorted slots assume someone else has had it apart and probably damaged the part. Inspect it closely to insure needles haven't been tightened enough to ream out jets and/or make a groove in the needles. Resist the urge to jamb a peice of hard wire such as from a bread wrapper tie through small holes, use a toothpick or SOFT copper or brass wire if needed.

Use caution and common sense with any cleaning solvents. Most carb cleaners are aggressive. Good against dirt, bad against humans.

When the parts look clean, clean them again. I usually do a final rinse with laquer thinner from my air brush. It evaporates completely with no residue. Duke suggested polishing the needles. I would also polish the throttle plate, the choke plate, and the float. The smoother the surface, the longer it takes for new dirt to stick.

Most important is to take your time. Spending an extra few minutes to get it right will save you hours of frustration down the road.

[dgjks6 6]

Did the carb rebuild today. Took it off, took off the bowl, replaces the pin thing, took off the plates, found a spring and a ball that fell out, went to the tractor shop, owner showed me where they go back in, cleaned everything with carb cleaner, put it back together, replaced gas line, and...

runs like brand new!!!!

no more surging - just a smooth, constant purr.

I think I did more of a good cleaning than a rebuild, there was a small jet thing (no idea what this is called) that was made of brass - dealer said just blow carb cleaner in it - don't try to take it apart.

[hounddoghundzsa 7]

Well as duramaxdavid stated at least you will know its done by rebuilding.

This is what I do when I rebuild a carb,

The first thing I do is check the throttle shaft for slop if its wobbly and has alot of play then that is most likely your problem. if it feels pretty tight then read on. if not you will need a carb rebuild kit and throttle shaft and bushing and thats a bit more tough.

1st make sure you have all the parts you will need (gaskets, carb to engine and engine to air cleaner) float needle and seat and bowl gaskets. before you get started remove the high speed and idle adjustment needles and make sure they are not pitted. If they are you may need those also. at this point remove the carb.

STOP! at this point if you are replacing needles and throttle shaft and a carb kit you may be cheaper in finding a good used or new carb weigh the cost of the parts VS new or good used.. If rebuilding is cheaper continue.

Dissasemble the carb by removing float bowl. remove pin in float, remove float and then remove the needle and seat, remove high speed and idle jets. take some carb cleaner and spray off all the loose crud off the carb ( I suggest this as not to spoil your carb soak) the best thing to do after all parts are removed is get a gallon can of solder seal or rector seal carb dunk cleaner or simular. try and get the kind with a little parts basket Auto zone sells these types Only soak degreased carbs in this solvent to make it last it will last along time if you do!

Then take the whole famdamily and soak all the parts try and give a little agitation every so often usually takes about 20 min to half hr. remove all the parts and spray off with carb cleaner then blow off with air hose. I Then reassemble and set float level per specs. I usually then polish the brass needles with some polish like brasso with a soft cloth I then examine the high speed jet and make sure all the port holes are clean and can blow air thru all of them (very important). after reassembly check your starting points for high and Idle adjustments. Make sure you install a new fuel filter also. That should get yer carb in top shape! Good luck!

Duke

Do you know what the factory suggested carb settings are for a k181? I bought a new carb for mine and was curious to know. Also, has anyone used the rolled cork or felt to make thier own gaskets? How did they come out?

Thanks