# motor problems, please help



## superflysmith (Oct 15, 2004)

This is for a lawn mower not an automobile but this seems like a good place to get help from. My problem is I can only get my lawnmower started by using starter fluid. Even after it has warmed up it still won't start without it. What could be a possible solution?


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## batty_professor (Jul 29, 2004)

Sounds like you have the typical "Briggs". The carburetor is very simplistic. It attaches to the top of the fuel tank with three or four screws. Between the carb body and the tank, is a gasket, with some tiny little flaps cut into it. Those flaps make reed valves in the sandwich, and with age they warp, making them useless for making fuel move. The repair kit should be about $5 at the hardware store. If you have something different from what I've anticipated, let me know.


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## superflysmith (Oct 15, 2004)

O.k. thanks. I'll check it out tommorow.


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## JamesO (Mar 30, 2005)

Do not forget to check and make sure you do not have water in the gas! See this all the time. Condensation can cause water to show up in the fuel, also storing the mower outside is not a good thing. 

Fuel may also be old. Try fresh fuel as well.

Easier than pulling the carb, but this may be needed. You will also find if you had water in the fuel by rust and/or aluminum corrosion inside the carb/fuel bowl area.

JamesO


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## MD_Willington (Jan 11, 2005)

JamesO said:


> Do not forget to check and make sure you do not have water in the gas! See this all the time. Condensation can cause water to show up in the fuel, also storing the mower outside is not a good thing.
> 
> Fuel may also be old. Try fresh fuel as well.
> 
> ...



I'll second that too...did you store the machine over winter without gas additives ?

MD


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## JamesO (Mar 30, 2005)

How high is that grass anyway?? 

JamesO


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## superflysmith (Oct 15, 2004)

I had the lawn mower running for about 20minutes than I was able to start it up again with the pull start but it still seems very hard to start. My plan was to run out the gas then put fresh gas in and see if it was easier to start. But that plan didn't work out because the grass was to long and the blades on the mower were dull so it was to hard to cut. So I got my lawn mower from home and used that instead. Needless to say I still don't know what's wrong with it. I might go out and get a Toro and be done with it, not sure yet.
BTW this is a Lawn Boy mower but I'm not sure it's a Briggs. I saw something that started with a H on the engine block but I can't remember what it said. It was a wierd name.


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## batty_professor (Jul 29, 2004)

An H? Does Homelite ring a bell. I think Homelite owns Lawnboy these days. That must be a two-stroke engine, that requires a gas-oil mix. It should have a float-bowl carb.


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## JamesO (Mar 30, 2005)

If it is a Lawnboy, probably 2 stroke, requires oil and gas mixture, if it was getting hard to start then maybe the engine is starting to sieze??

I do know much about the newer Lawnboys, however, all the older ones I was familiar with were 2 stroke. 

Does the engine have an Oil fill port somewhere, if not, probably a 2 stroke!

JamesO


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## superflysmith (Oct 15, 2004)

It does have an oil fill pour. I don't think it said Homelite. Now it's bugging me. 
I'll have to check it out tommorow right now I'm at home. The lawnmower I'm having problems with is at my work.


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## batty_professor (Jul 29, 2004)

A simple thing, and easy to overlook, make sure the fuel cap vent is open so as not to cause a vacuun to develop in the fuel tank.


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## Volt-Schwibe (Jan 12, 2003)

well, i am interested in knowing how much bad gas was in it.

if you ran enough bad gas through it, you might have a clogged jet, and then you would need to spray a fuel into it for it to run.

also, i second what batty said about the carb gasket.

alot of these briggs motors have a simpler gasket though, without reeds.

i would try taking the spark plug out, and spraying the carb inside heavily with carb cleaner as you pull on the cord. putting some fresh gas in it before this is a good plan, you want them gums and rosins to dissolve.


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## superflysmith (Oct 15, 2004)

O.k. I just checked out the lawn mower. I made a mistake when I said the engine started with an H, It is a Tecumseh 6.25hp 4cycle engine. The link above shows a diagram of the motor. I have the Lev120.
I just gave the motor a pull just to see if I could start it since it was running last week for awhile. The problem seems like there is a lot of resistance when I pull start it. I was comparing it to my own personal lawn mower which is still here at my work. I could not get it started although I'm sure I can if I try using starter fluid again.
I plan on try all the suggestions above to see if they solve the problem. Thanks for all your help.


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## batty_professor (Jul 29, 2004)

-That carburetor does not have a choke, automatic or otherwise. Instead there is a primer button on the side of the carb. You must press it fully, 3 times or so before cranking. (there should be a label to that effect under the layer of dirt). When this works correctly, and you get the hang of it, ONE PULL!


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## Bald Eagle (Feb 25, 2005)

*Tecumseh carbs*

As the Prof said these are simple carbs with a float boal on the bottom. I have found that last years gas left in them usually causes problems. I often remove the brass bolt (a banjo bolt) usually a 9/16 wrench and clean out the bowl and the needle and seat. It is often easier to remove the whole carb and do it on a bench. There is an aluminum post that the banjo bolt screws into. At the base of this post there is a small hole that allows fuel to enter the post and be metered by the main jet located in the banjo bolt. This small hole often is plugged or partially plugged. A small drill used with your fingers, not a power drill! works well. Sometimes I can use a piece of wire to open it up. Make sure the main jet is clear, put it all back to gether drain out the old fuel, put in new, premium is best at least for the first tank and it should be good to go. If that doesn,t work, there may be other slightly more complicated carb problems with the primer circuit (leaks) . At that point probably best to either let a pro look at it or get a new one. Good luck.


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## batty_professor (Jul 29, 2004)

Superfly, how high is that grass by now?


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## superflysmith (Oct 15, 2004)

I have not attepted to fix the lawnmower yet so it would be about a foot in a half by now but I brought my mower from home to work. So it's all good right now. I still intend to fix the mower if I can follow all your instructions.

I just bought a new weed trimmer today because the old one was a pile of junk. Never by a Weed Eater that thing was a problem from day one. I ordered a Troy Bilt TB25cs today. I'm hoping that will work better. Today I used my trimmer from home which really sucks because it's an electric trimmer and there is alot of land at my work. Extension cords were everywhere. But my electric trimmer does alot nicer job than the pile of crap Weed Eater.


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## mrpctek (May 24, 2005)

*help having lawn mower problem*

I've tried it all. the mower will not draw its own fuel. I've cleaned all jets and checked the float spring. the bowl is filling. i cleaned the little hole on the shaft the 9/16 bolt that holds the bowl on. the primer only seems to blow air. no fuel is coming out to prime. the mower starts right up with either starting fluid or reg fuel sprayed in the air filter intake. what the heck is going on. how does fuel get to the jet that is in the bolt holding the bowl on?
or help, i can fix just about anything but this has got me stumped.
thanks,
pc


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## Red neck Nerd (May 27, 2005)

*Gas Line?*

have you checked to make sure that the fuel line is clean and clear? doe it have a fuel filter? if so check it. if you feel comfortable with it you may want to open the "head" up and clean the inside of the engine. ie: cylinder, piston, valves etc. probibaly not needed but can add a few more hp if you get it running


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## Red neck Nerd (May 27, 2005)

have you checked the Carburater settings? reguards fuel and air mixture.


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## batty_professor (Jul 29, 2004)

Don't remove the head, it isn't necessary, and isn't going to fix your carburetor. The brass "plug" you mention, is it sort of hollow? and is this on a Tecumseh? The "plug should have a small (very small) hole in it, that acts as a fuel "jet" basically a flow restrictor, so the right amount of fuel is allowed to pass to the tube that protrudes into the venturi. That tiny hole is probably plugged. It may be difficult to find as well. it should be in the unthreaded shoulder area halfway between the threads and the hex. It should be about the size of #26 to #22 solid wire. Do not use a drill bit to open it, if the hole becomes enlarged, the mixture will become too rich.


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## Red neck Nerd (May 27, 2005)

True you do not need to remove the Head if the carb is not doing its job. However if it has been run for a few years i would highly recomend it, as it does improve the preformance of an engine. i just did an overhaul on a Briggs and Stratton 11 Hp horizontal drive and easily regained some lost umph. also in the process of overhauling a vertical drive tecumseh 10 hp from a sears mower found with a free sign on the road, the mantel or the metal cover on the engine was packed with a mouse nest, the carb and air intake manifold had standing water in it as well as the cylinder... the oil was more like sludge... i'll let you all know how it goes.


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## JamesO (Mar 30, 2005)

Carb is the likely cluprit, however, I have seen problems with carbon build up on the valves cause the intake stroke to be weak and not pull in fuel well, but the same engine respond to starting fluid or WD40. Also had similiar issues with leaky/blown head gaskets in the past.

Unless it was clear that the fuel was gummed up, had water or excessive dirt, may be worth pulling the head for inspection??

I have performed the poor mans valve jobs without removing the valves, using grinding compound with the valves in the engine. Rotate the engine until valve is almost closed, after applying grinding compound, and rotate valve with your fingers. Open valve up, wipe away compound, use spray carb cleaner to finish up and move on!!! Just make sure you are cleaned up well, otherwise you will be in for some surprises.

Might as well change the oil while your hands are dirty. Have not seen this on a mower, but have run across it in cars. Gasoline dilution of oil causing poor compression due to lack of oil on cylinder walls. More likely the hydralic lifters will not pump up, than the slick cylinder walls! Causes poor starting and lack of power. Probably be a bit hard to be the issue on a mower (solid lifters), but all things are possible.

BTW, how high is that grass!!

Good luck.

JamesO


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## Red neck Nerd (May 27, 2005)

you may laugh when you read this... but when cleaning the valves an old toothbrush does quiet well. also when cleaning the head a putty knife works pretty good too, and of course if you want that engine gree of gunk and grime try using some Gunk engine bright degreaser. be forwarned that gunk does distill oil making it possible to clean with water, translation dont get it in the crank case, cylinder or carburator. if you do... pray to the engine gods you can clean it all out otherwise it just spells trouble


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## Volt-Schwibe (Jan 12, 2003)

JamesO said:


> I have performed the poor mans valve jobs without removing the valves, using grinding compound with the valves in the engine. Rotate the engine until valve is almost closed, after applying grinding compound, and rotate valve with your fingers. Open valve up, wipe away compound, use spray carb cleaner to finish up and move on!!! Just make sure you are cleaned up well, otherwise you will be in for some surprises.



this is no joke, you leave any of that polishing compound in there, and your motor will more or less be polished to death internally as it runs.

for real.


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## JamesO (Mar 30, 2005)

I had to redo an 14 HP engine a "professional shop" reworked. They used a dingle ball cylinder hone. Unfortunately one of the dingle balls broke off the hone and got closed up in the crankcase. 2 months later it came to see me. I found about half the dingle ball and the stem in the crankcase.

Well you guessed it, short block was REAL expensive, so had to buy crank, rod, piston and rings 0.040" overbore. Luckly the cam was ok, not sure how it survived?? 

The professional shop claimed "No Way", we would have never let something out the door like that!!! The customer had to eat this one.

JamesO


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## Red neck Nerd (May 27, 2005)

well i finished the tecumseh rebuild, fired it up today and for an engine with standing water in it and a poor mans rebuild on it id say i just saved a good 2-300 dollars on an engine, as they are about $250-$350 brand new. for a freebie not bad


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## johnwill (Sep 26, 2002)

I'm surprised nobody suggested the obvious, replace the spark plug.

FWIW, I have a snow blower with a Tecumseh engine, and after about 10 years, I was having carb issues. I just bought a new carb for $20 and slapped it on a few years back. Still going strong. :smile:


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## Red neck Nerd (May 27, 2005)

after working on an out board engine this labor day weekend i was reminded of a trick my father taught me. use a squirt bottel of some kind and spray a little gasoline into the carb via the air intake, if there is a spark which it sounds like there is it should get the engine to turn over and startup similar to using started fluid. after doign this a few tiems it should start to draw its own gasoline. you may want to if you havnt already take the bowl off of the carburator and make sure it is clean and clear. it may just be easier to buy a new carburator for it. 


btw how long is that grass?


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