Carburetor needle seat cleaning

Auto Doc's

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Hello Folks,

Carburetor cleaning can be a chore, but sometimes it takes more than just good carburetor cleaning and a round in the ultrasonic bath. I try to save what carburetors I can to avoid aftermarket copycat versions.

For those that hate Nikki carburetors, I will simply say don't open them unless you put a complete rebuild kit in them. I work on many mower carburetors, but also ATV and automobile carburetors. I've been rebuilding them for many years. But, once in a while I run into one that will give me headaches.

Last week I was working on a problem carburetor on a 2003 Honda Rancher 350 ATV, and it was giving me fits. It has a press in needle seat. No matter how I adjusted the float level it would eventually spring a leak at the bowl overflow.

Finally, I got online to check out some of The You Tube videos and a guy brought up and interesting procedure for cleaning the needle seat and polish it in these ATVs.

Over time gasoline develops a resin or shellac and that stuff is difficult to remove even with the best carburetor cleaner. The solution he came up with was to use a Q-tip with the carb spray. Insert the Q-tip cotton tip into the seat and gently spin it. It cleaned and polished the seat perfectly.

It worked great and I had no more needle leak problems.

Hope this helps someone.

I don't think this same method would work on any 2-stroke handheld carburetor because the parts are way too small.
 

Tiger Small Engine

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Hello Folks,

Carburetor cleaning can be a chore, but sometimes it takes more than just good carburetor cleaning and a round in the ultrasonic bath. I try to save what carburetors I can to avoid aftermarket copycat versions.

For those that hate Nikki carburetors, I will simply say don't open them unless you put a complete rebuild kit in them. I work on many mower carburetors, but also ATV and automobile carburetors. I've been rebuilding them for many years. But, once in a while I run into one that will give me headaches.

Last week I was working on a problem carburetor on a 2003 Honda Rancher 350 ATV, and it was giving me fits. It has a press in needle seat. No matter how I adjusted the float level it would eventually spring a leak at the bowl overflow.

Finally, I got online to check out some of The You Tube videos and a guy brought up and interesting procedure for cleaning the needle seat and polish it in these ATVs.

Over time gasoline develops a resin or shellac and that stuff is difficult to remove even with the best carburetor cleaner. The solution he came up with was to use a Q-tip with the carb spray. Insert the Q-tip cotton tip into the seat and gently spin it. It cleaned and polished the seat perfectly.

It worked great and I had no more needle leak problems.

Hope this helps someone.

I don't think this same method would work on any 2-stroke handheld carburetor because the parts are way too small.
You can also put a wooden Q-tip with valve lapping compound on it and chuck it up in a drill at low speed. Then switch to carburetor cleaner, then blow out the seat.
 

hlw49

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You can use toothpaste not the jell the white paste type and a Q tip.
 

Scrubcadet10

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Yep, I always Q tip the seat really good
 

Auto Doc's

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The one design I forgot to mention is the carburetors with the Viton seat insert that has to be pressed in. I have not found a good way to clean them, and they are a pain to work with if a new seat has to be installed.

Most of the ones I have come across have the needle stuck badly from old, dried fuel resin and are seldom worth the effort to save.
 

Rivets

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Doc, I assume you are referring to Tecumseh carbs with the replacement seats. Personally I have found these are about the easiest carbs to clean and rebuild. Removing and installing a new seat can’t be easier if you have the correct tool. One thing I have found through experience is to always install the new seat dry. For some reason when I first started teaching carb rebuild, adding a small amount of oil resulted in leakage. Never found out why, just always installed dry with no more problems. Here is the tool.
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