# Push mower



## jasonvanorder (Feb 23, 2009)

Ok guys I am no small engine guru so i need some help with this. The little briggs and straton engine on my push mower is acting up. It starts right up first pull but no matter how much gas i give it it will surge. Last weekend i got it out changed the plug and the oil,gave it some fresh gas and started right up ifrst pull. Mowed 3/4 of the lawn just fine then it started to surge. Check the tank and it was full of junk so i was thinking it sucked some up and plugged the carb. Well after cleaning the carb and gas tank i still have the same problem. if i hold the trottle open by hand it runs perfect. any ideas on what to check next?


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## Doehead (Sep 7, 2010)

It sound like it's dirty inside. How's your air cleaner?
That could do that. Have you checked the float bowl? If you take it off and blow out the holes in the screw that could take care of it too. 
It a minor problem a little tlc should fix.


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## jasonvanorder (Feb 23, 2009)

Doehead said:


> It sound like it's dirty inside. How's your air cleaner?
> That could do that. Have you checked the float bowl? If you take it off and blow out the holes in the screw that could take care of it too.
> It a minor problem a little tlc should fix.


 
Air filter is new only has 3 or 4 runs on it. I took the carb off and pulled it apart and cleaned everything thats what has me at a loss.


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## Doehead (Sep 7, 2010)

Make sure the screw holding the float bowl on is clean. Just because an air cleaner is new doesn't mean it's working properly, does it surge when the air cleaner is off? If it does spray some carb cleaner while its running. If that's not it check the spring on the governor.Rev it up when it's running then watch the spring. You can fix it.


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## Doehead (Sep 7, 2010)

Check your gas cap too, they are a breather, if its clogged or damaged your engine will starve for air. Check your gas line, it may be collapsing or sucking air. Thanks for reminding me about maintenance, I just went over mine, started first pull, it's a 10yr old Craftsman.


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## Sling (Aug 2, 2005)

also check your governor linkage for binding....lots of video's on youtube


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## FERG 06 (Oct 6, 2006)

It's not getting enough fuel. The main jet in the bowl nut screw probably has something in it. Many miss this when they clean out the bowl. Of course this advise is based on it being a carb with a fuel bowl. If it's a pulsa-jet carb (with a diaphragm) then it will need a new diaphragm.


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## j-rock (Dec 17, 2008)

try a little sea foam in your gas


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## FERG 06 (Oct 6, 2006)

Seafoam won't get rid of a piece of grass or other junk clogging a screen or passage. It's also is ineffective on the hard crusty crap I routinely clean out of the jets. And it won't fix a deteriorated diaphragm. All of which can cause surging.
Fasted fix is to disassemble, physically clean & reassemble w/whatever new parts are needed.


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## jasonvanorder (Feb 23, 2009)

FERG 06 said:


> It's not getting enough fuel. The main jet in the bowl nut screw probably has something in it. Many miss this when they clean out the bowl. Of course this advise is based on it being a carb with a fuel bowl. If it's a pulsa-jet carb (with a diaphragm) then it will need a new diaphragm.


 
+1 on the pulsa-jet carb. no fuel bowl to clean. Ran a cap full of upper engine cleaner we have for fuel injectors and that took care of it. Smoked a nasty grey/black for about 15 min but now it runs like brand new. must have been a bunch of junk built up in there. now just gotta change the oil and she should be good to go! Thanks for the help everyone


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## Greenbush future (Sep 8, 2005)

j-rock said:


> try a little sea foam in your gas


This has fixed more "small problems" than anything else for me, try it before you tear it down.


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## Sasquatch Lives (May 23, 2011)

Doehead said:


> Check your gas cap too, they are a breather, if its clogged or damaged your engine will starve for air. Check your gas line, it may be collapsing or sucking air. Thanks for reminding me about maintenance, I just went over mine, started first pull, it's a 10yr old Craftsman.


Had the same problem with mine and the gas cap was the problem.


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## Doehead (Sep 7, 2010)

For small engines, there sure is a lot of small parts isn't there?


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## j-rock (Dec 17, 2008)

hey fergi seafoam


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## Big Reds (Oct 14, 2007)

Governor problem for sure. This is the only mechanism that will make an engine allow more than normal fuel into the carb. mking it "surge". The governor senses the engine needs more fuel from a loss of air flow to the governor blade and opens the throttle moe. If the diaphram as bad, it wouldn't run. If the carb was clogged, it would stall. 
Check the linkage next to the flywheel. You may have to pull the spin start cover to do so. May be simple as a faulty return spring on the linkage.


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## 2ESRGR8 (Dec 16, 2004)

Inline fuel filter?


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## FERG 06 (Oct 6, 2006)

Greenbush future said:


> This has fixed more "small problems" than anything else for me, try it before you tear it down.





j-rock said:


> hey fergi seafoam


Not knocking seafoam. Just used some yesterday. I have what's left over from a case I bought on the shelf. As stated it won't get rid of debris such a grass. Works great on carbon and gum build up but once it's completely clogged, forget it.



2ESRGR8 said:


> Inline fuel filter?


This is the problem w/diagnosing things on the internet. If the OP is correct and he has a pulsa-jet carb mounted on the tank then there is no inline filter. Screen in the carb, yes. Which is why I recommend disassembly and physically cleaning the grass, dirt, cottonwood seeds, etc that collect on the screen that seafoam won't touch. Do that and a half hour later (a bit longer if you've not done it b4) and it's done. No farting w/it for hours/days. You will also be able to replace the diaphragm that's part of routine maintenance. But again this is based on it being a pulsa jet. Shoot me the model # and I'll confirm it.


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## FERG 06 (Oct 6, 2006)

Big Reds said:


> Governor problem for sure. This is the only mechanism that will make an engine allow more than normal fuel into the carb. mking it "surge". The governor senses the engine needs more fuel from a loss of air flow to the governor blade and opens the throttle moe. If the diaphram as bad, it wouldn't run. If the carb was clogged, it would stall.
> Check the linkage next to the flywheel. You may have to pull the spin start cover to do so. May be simple as a faulty return spring on the linkage.


This is one way to look at it. The govenor works off mechanical or air speed. when the engine slows down the govenor opens the thottle calling for more fuel to try to speed it back up. But there is a reason the engine slows down. It's not getting enough fuel.
Not enough fuel, the engine slows. Gov opens the throttle, carb is clogged & can't supply the fuel so engine slows down again. Slows enough, gov opens thottle......repeat. If you have a fuel bowl carb, drop the bowl, clean the main jet, problem solved.
Now sometimes the gov linkages & holes become worn causing binding & surging.
Gotta go repair some lawn mowers. Got people standing in line already this morning.


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## jasonvanorder (Feb 23, 2009)

FERG 06 said:


> Not knocking seafoam. Just used some yesterday. I have what's left over from a case I bought on the shelf. As stated it won't get rid of debris such a grass. Works great on carbon and gum build up but once it's completely clogged, forget it.
> 
> 
> 
> This is the problem w/diagnosing things on the internet. If the OP is correct and he has a pulsa-jet carb mounted on the tank then there is no inline filter. Screen in the carb, yes. Which is why I recommend disassembly and physically cleaning the grass, dirt, cottonwood seeds, etc that collect on the screen that seafoam won't touch. Do that and a half hour later (a bit longer if you've not done it b4) and it's done. No farting w/it for hours/days. You will also be able to replace the diaphragm that's part of routine maintenance. But again this is based on it being a pulsa jet. Shoot me the model # and I'll confirm it.


 
You sir are correct. It is a pulsa jet carb mounted on the tank. When i first took it off i only looked at the carb what i didnt do is look at the tank other than to drain and filter the gas in it. Looking at the tank where the carb mounts to it it was full of more dirt and junk. Cleaned that out and ran the cleaner thru the gas as i said earlier and she runs like brand new. I knew when i put it away for the winter that the tank needed to be cleaned out but i told my self i wont forget that that really worked out for me.


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## FERG 06 (Oct 6, 2006)

jasonvanorder said:


> You sir are correct. It is a pulsa jet carb mounted on the tank. When i first took it off i only looked at the carb what i didnt do is look at the tank other than to drain and filter the gas in it. Looking at the tank where the carb mounts to it it was full of more dirt and junk. Cleaned that out and ran the cleaner thru the gas as i said earlier and she runs like brand new. I knew when i put it away for the winter that the tank needed to be cleaned out but i told my self i wont forget that that really worked out for me.


Sounds like you did a great job. I could put you to work! :lol:
If that thing ever starts sputtering (not surging) replace the diaphragm. It's common for those plastic carbs to warp and once you take'em apart they won't seal back up. If so, add your old gasket to the new one that comes w/the diaphragm & it should seal.


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## Big Reds (Oct 14, 2007)

if i hold the trottle open by hand it runs perfect.

This is what made me believe it was the governor. Glad it is all good.
Great advice given on this site.


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## jasonvanorder (Feb 23, 2009)

ok ferg new problem. Ran it at the shop for a few min this morning after putting a new blade on. Now when i got it home tonite it will not start. When it trys to start it will spit and sputter and blow white smoke but will not stay running. Could it be that it just got too cold in the back of my truck or is there something else i should look for?


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## jasonvanorder (Feb 23, 2009)

Never mind got it going an ew diaphram and an unfouled plug and she was running like new again. thanks for all the help.


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## FERG 06 (Oct 6, 2006)

Yeah, white/blue smoke is oil. Black is too much fuel.
On that engine you don't want to turn the blade/engine when it's on it's side or you'll pump oil above the piston and out the muffler fouling plug not to mention it's dangerous unless you pull the plug wire.
Sorry late on the reply, been a little busy lately.


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## jasonvanorder (Feb 23, 2009)

It sat up right from the time istarted it that morning till that nite so not a clue there. But she runs like a champ now. Really going to work her tonite going to my cousins house to mow. He is a bit on the lazy side and hasnt done a thing yet this year. His yard is getting really shaggy.


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