Lawn Tractor Problem

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  #1  
Old 10-15-02, 03:22 PM
Billsc
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engine stalls on riding mower

I have basically the same problem as dave beauchamp. The engine starts great ...I can let it warm up with the choke partially open ..then when I start moving and engage the blades it stalls out...if I quickly pull the throttle back almost to idle it keeps running ....I push the throttle foward again and it even dies at times when I am not engaging the blades. But....if I only open the throttle about 15% I can engage the blades okay....no stalling...I have cleaned the fuel filter and tried backing out on the mixture adjustment about 1 1/2 turns ...still does it...I did get it running good enough once to mow about a third of my one acre lawn but then it stalled and died ...when it was mowing I could almost open it wide open. I first thought perhaps that one of my blade bearings had frozen but they all three roated fine when I got it to mow...I am confused but think it almost has to be the fuel ....
Any suggestions...? It is a Briggs and Stratton 18'5 hp Twin cylinder...BTW ..I clean the plugs too...
 
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  #2  
Old 10-15-02, 09:15 PM
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Hello Billsc!

This is a common problem on the twin cylinder briggs engines. What you will need to do is: Remove the air filter and housing. Remove the bowl drain plug with a 5/8" wrench. Using a 5/16" socket or nutdriver, remove the 4 screws that hold the top of the carb on. Remove the top and clean out the bowl and all passages. Look into the hole that the drain plug goes into. You will see that there is a jet screwed into the carb through that hole. It takes an allen wrench (can't remember what size) to get it out. Remove it and clean it and also clean the port that it screws into. If you notice any bad or broken parts or gaskets, then replace them. Then reassemble and mow! It is really an easy job. Less than 1 hour for the novice with ordinary hand tools.

Let us know how it goes!
 
  #3  
Old 10-16-02, 04:03 AM
Billsc
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Thanks....Will give it a try....Will let you know how it works..
 
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Old 10-17-02, 12:38 PM
Billsc
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Thumbs down

Hi...
Tried the method you suggested ....Lots of junk in the bottom pulg hole...also took the three small screws out on front of carb. Small spring with gasket ....block with holes for air and gas...lots of junk here too...cleaned it all out ....THEN....put it back as I had thought it came out....Put gasket with spring on inside toward carb inside the block....There was an outline of the spring so I was sure that was where it belonged. Then put on cap with three screws....Tried starting it....put small amout of gas in top of carb....started it ....ran slow for a few seconds so I gave it more throttle....Gas and oil mixture shot out of air hole that goes to air filter.....Ohh gawd....did I kill it fer good? Help...

It did smoke and run okay at very little throttle ...
 
  #5  
Old 10-17-02, 07:20 PM
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Ok, the junk in the carb jet was the initial problem. The 3 screws that you removed from the front of the carb are the fuel pump screws. When this is disassembled, there are actually TWO very tiny copper colored springs. They are VERY easy to lose without even seeing them. When the fuel pump is disassembled, the diaphragm usually needs to be replaced before reassembling. The kit comes with replacement springs too. This may be a contributor to your problem, but there may also be another problem. The backfire/spitback and smoke you experienced is what is making me think that the engine is flooding out. Did the needle get positioned back in place? Could the float be stuck? Could the float have gotten bent out of adjustment?

To check the float adjustment, remove the top of the carb. Then turn it over so that the float is on top. Make sure the needle is in place. The float should be parallel to the surface of the top of the carb. It can be bent out of position easily with just a little pressure and would be easy to do without realizing it when reassembling the carb.
 
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Old 10-17-02, 08:07 PM
Billsc
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I too think the float could be the problem...After just cleaning the bottom plug where I found a load of junk and trash...I replaced it and tried mowing...it started great and I got about ten minutes of mowing before it died again...Then I removed the bottom plug again and the top of the carb...After cleaning that I tried getting the jet out with an allen wrench but was unable to get the wrench seated properly...that is when I took the fuel pump plate off and found loads of junk there too...I was careful to replace the small springs and the gasket with the spring ....This is when I tried restarting it by pouring a few drops of gas into the top of the carb...It started and ran very slow and this is when I gave it more throttle and the gush of oil and gas came out the air hole in the filter. Fortunately I had not replaced the filter ...I checked the oil and it seem to have been diluted with gasoline ....I tried starting it again and it again ran until I gave it more gas ..it then gushed out oil and gas again thru the air filter hole...

I will run down to Columbia tomorrow and get a kit for the card...also I am going to change the oil since it seems very diluted...
Yes...The carb was the trashy problem to begin with I am sure...Guess my fooling with it and choking it to try and start it caused the choke to stick....
Will take the top off again and check the choke ...Hope thats all it takes...Grass is growing ....
Thanks for helping an old cripple man...
 
  #7  
Old 10-18-02, 04:00 PM
Billsc
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Talking

SUCCESS!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Yeppers....I took the carb top off and there is a copper looking clip that was not under the float clip....I put it under the clip and recleaned the bowl....Reassembled it and tightened all the screws and bolts all around the carb for a second time...Drained the oil and added new oil....Drank a coke...the added gasoline to the tank....Started right away....ran it slow cause it was smoking big time from the exhaust...after a few mintutes I gave it more throttle...still no spitting out thru the air hole.... Still smoking....I retightened the screws holding the fuel pump ....there was a small leak there...still had not installed the new diaphram ...guess I didn't need it at this time cause smoking stopped and I ran throttle almost full ....Ran great ...I readjusted the carb mixture ....Still running great ...mowed the one acre ...only used half throttle to more ...never a sputter or skip....Guess I am good to go for now...

Now if you have a secret way to get to the blades and zerk fittings under the deck to sharpen and grease the hubs I would be happy....I raise the mower with a come along...lots of trouble...still have to almost lay down to get to them...

Thank you so much for your help....Its been a life saver ...the mower is just too big to try and take it anywhere for repairs...Got a truck but no way to load it...

Again...Thank you....I used to not be able to spell mechanic...NOW I ARE ONE....(smiling)
 
  #8  
Old 10-18-02, 07:27 PM
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Allright!! Good job! Unfortunately, I have no really good way to advise how to get under the mower to access the blades and grease fittings. There ARE ways, but they aren't really safe. Any way you do it, make sure to use jack stands! The safest but most troublesome way is to remove the deck.
 
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