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I am the proud owner of a 2003 Lawnboy 10323 mower. Recently I started having an issue with the carb leaking gas into the engine, which as I understand it is a fairly common issue with these plastic carbs. It was bad to the point where when I pulled the starter rope gas would gush out of the muffler.

My short term fix currently was to install a gas shut off so gas would not continue to leak into the carb causing this problem while it sits in the tool shed for 5 days waiting for the next mowing. Other then this issue the mower runs great and starts first pull with to 2/3 pushes of the primer bulb and no choke.

To my question. I need to repair the carb, obviously. Should I buy the complete carb kit 107-4607, which is essentially a completely new carb, in kit form? There are many parts there that I would assume I do not need or should I just go to parts tree and pick up the particular replacement parts that are causing this gas leak blow by problem?

If I did just buy the particular parts, which ones should I get that are causing this issue? Not trying to nickle and dime this issue. I will buy the complete kit it need be, just wondering what others have done here to rectify this issue.

Cheers.

The only parts that can cause flooding are the float, needle and seat. If you renew these, you will not have flooding.

Thank you for the reply. So, that would be part #16 on the exploded drawing below, along with a new float, part #10?

Thank you.

Also, I remember from a few years back someone here had some info on drilling out the needle valve to minimize surging. I searched but could not find the thread that related to that. Pretty sure it was this forum, but I could be wrong. Anyone that knows of this offhand I also would appreciate that info.

Cheers.

TiredRetired said:

Thank you for the reply. So, that would be part #16 on the exploded drawing below, along with a new float, part #10?

Thank you.

Also, I remember from a few years back someone here had some info on drilling out the needle valve to minimize surging. I searched but could not find the thread that related to that. Pretty sure it was this forum, but I could be wrong. Anyone that knows of this offhand I also would appreciate that info.

Cheers.

View attachment 28951

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On that diagram, it would be parts 10 and 16. When the float is all the way up (when the float chamber is full of gas) the little valve (part 16) should shut off so that no more gas can flow into the chamber. And you may not need a new float (part 10). That valve, most likely, is not sealing properly.

Re. "drilling out the needle valve to minimize surging" -- That's another issue entirely that has nothing to do with the problem you're having.

Two-Stroke said:

On that diagram, it would be parts 10 and 16. When the float is all the way up (when the float chamber is full of gas) the little valve (part 16) should shut off so that no more gas can flow into the chamber. And you may not need a new float (part 10). That valve, most likely, is not sealing properly.

Re. "drilling out the needle valve to minimize surging" -- That's another issue entirely that has nothing to do with the problem you're having.

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Yup, just what I figured. Thank you to all. I will order the parts and see how it goes.

Another question. Unless I am mistaken, from what I have read this is a fairly common problem with these carburetors. What exactly is it that makes these carbs so susceptible to this issue? For as long as I can remember I have been using Ethanol free gas and only LawnBoy two cycle oil. I am so anal that before I put the gas in the can, I put a couple gallons in my truck to make sure the lines are clear of E10. I follow this procedure with all my two stroke engines and the lawnboy is the only one that seems to have carb issues on a fairly consistent basis.

Cheers.

A new needle and seat are all you need to fix the leakage issue you described. As far as drilling the jets, a #77 drill (.018") is used for the pilot jet, and a #67 drill (.032") is used for the main jet. Be forewarned the mower will use more gas than before. Me personally if the mower ran good without surging, I wouldn't drill out the jets.

I own two 10323's, a 99 bought new and a 03 bought from Craigslist, the 99 never had a surging issue, the 03 did. I ended up drilling the jets on the 03. It fixed the surging issue, but like I said, it does use more gas.

Jeff

I would replace the needle, valve and float as stated, probably less than 15.00 for all. If your float is not stopping the gas it could be out of adjustment. The float has a some what of a flimsy tab. That could have just worked its way out of adjustment. Best way I found to adjust is to remove carb from mower, take bowl off to remove all gas, put bowl on just holding with your hand and turn up-side down, blow into gas inlet, should not be able to get any air through, if you can bend the tap on float up slightly, and do same procedure until you cannot blow air in. Then turn right side up and do the same, should be able to get air through with little restriction. Good luck, by the way I removed and adj carb 4 times before I tried this method adjusting float.

jp1961 said:

A new needle and seat are all you need to fix the leakage issue you described. As far as drilling the jets, a #77 drill (.018") is used for the pilot jet, and a #67 drill (.032") is used for the main jet. Be forewarned the mower will use more gas than before. Me personally if the mower ran good without surging, I wouldn't drill out the jets.

I own two 10323's, a 99 bought new and a 03 bought from Craigslist, the 99 never had a surging issue, the 03 did. I ended up drilling the jets on the 03. It fixed the surging issue, but like I said, it does use more gas.

Jeff

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Excellent. Which ones are the pilot jet an main jet in that exploded drawing. IF I decided I want to do this mod, I would like to be sure I have the right jets. :laughing:

lewb said:

I would replace the needle, valve and float as stated, probably less than 15.00 for all. If your float is not stopping the gas it could be out of adjustment. The float has a some what of a flimsy tab. That could have just worked its way out of adjustment. Best way I found to adjust is to remove carb from mower, take bowl off to remove all gas, put bowl on just holding with your hand and turn up-side down, blow into gas inlet, should not be able to get any air through, if you can bend the tap on float up slightly, and do same procedure until you cannot blow air in. Then turn right side up and do the same, should be able to get air through with little restriction. Good luck, by the way I removed and adj carb 4 times before I tried this method adjusting float.

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Yeah, I think I will order the float as well. Thanx guys!!

The main jet is item #7 on your exploded diagram, the idle jet is on the side of the carb. You have to remove the black sticker that has a model number on it to get at the idle jet.

You might want to take the cover plate off the transfer chamber under the mower deck, you'll find several ounces of gas in it. While there, you can check your exhaust ports to see if they are clogged and need cleaning. You'll need a tube of high temperature silicone sealant to reattach the plate.

Jeff

jp1961 said:

The main jet is item #7 on your exploded diagram, the idle jet is on the side of the carb. You have to remove the black sticker that has a model number on it to get at the idle jet.

You might want to take the cover plate off the transfer chamber under the mower deck, you'll find several ounces of gas in it. While there, you can check your exhaust ports to see if they are clogged and need cleaning. You'll need a tube of high temperature silicone sealant to reattach the plate.

Jeff

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Thank you.