tiller engine needs repair

Old 05-08-04, 07:03 AM
jim wheely
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tiller engine needs repair

i am trying to repair a 4 horse briggs and stratton. i am a complete novice. here is where i am at.
i got it to spark by cleaning the magneto and points. it now runs but only if i cover the air intake and basically smuther it.
it has a diaphram carb. i have cleaned the carb and replaced the diaphram.
i see flames come out of the exhaust. and i have seen it in the carb.
i have been told it may be a sticky valve. so i removed the cover over valve springs and the valves seem to move freely. (but i have not removed the head so i say seem to move freely)
the pionts have a gap in them and i do not know if it is supposed to be there or if they are worn out)
please help the motor is on a tiller and the weeds are over taking my garden
Old 05-08-04, 09:20 AM
Terminator20's Avatar
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Does your carb have adjustment screws? If it does, you may have messed with them. It sounds like the engine is running lean to me. Please post your engines model numbers so we can help you better. The numbers should be stamped in on a plate, or on the shroud somewhere. Thanks...
Old 05-08-04, 09:34 AM
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Hello Jim

Lets start with the points...There should be a gap, this will be .020 when fully open (keyway in the crankshaft is straight up). This gap is critical in order for the spark to cccur at the right time as is a good flywheel key. Your having to choke (place your hand over the carb opening) the carburetor in order to keep it running is a sign that you have restriction at the carb. You said you replaced the diaphragm but nothing else. To be done right, you need to remove the tank/carb assembly and thoroughly clean. The carb has two pick-up tubes which drop into the tank. These as well as the passageways in the carburetor are likely plugged up with varnish. Soaking the carb in a good solution, such as NAPA Carburetor Cleaner #6401 should do the trick. Take notice that this solution is very strong and will damage all rubber components and most plastic components thereby necessitating the removal of such before soaking the carburetor. If you plan on servicing yourself, let us know and we'll walk you through the proper procedures as well as any replacement parts you will need. Try this first though...the carburetor has an adjustment on the right side (opposite the diaphragm), turn this screw in until carefully bottomed then back out one and three-fourths turns. This will be an initial adjustment on the rich side...but if this is all the problem is, it should run. Let us know.
Old 05-08-04, 10:06 AM
jim wheely
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ok i said i was a novice i had been trying to fix it with the air cleaner off . when i put the air cleaner on it runs fine .
so i guess that is a rookie mistake.
thanks for the reply's .
thanks for the info on the points. i just bought an acreage so i see myself making many repairs in the future.
why pay someone when you can....
Old 05-08-04, 10:28 AM
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Hello: Jim

You are very correct. Do it yourself is a good method. I suggest buying either the service repair manual for that specific engine or any generic small engine service repair manual. Plenty to learn and can be a good asset to have for any novice or anyone with small engine power equipment.

Small engine repair parts, generic repair manuals and additional help are all available at all local small engine repair shops and or lawn mower repair shops in your area. Shops and dealers are listed in the phone book directory.

Some additional help here:
Engine Codes: ...(Engine Manufacturer Web Sites Included)

Briggs and Stratton Home Page:

Briggs and Stratton Manuals:

Regards & Good Luck. Sharp Advice.
Master Small Engine Tech. Web Site Host, Forums Monitor and Multiple Topics Moderator. "Accurate Power Equipment Company." Engine Diagnostics Services & Repair. Fast...Fair...Friendly & Highly Proficient Services....
Old 05-08-04, 10:42 PM
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Glad you got it fixed! Yep---been a while since I worked on a choke-a-matic, but they don't do well with the air filter off....or you at least have to put the air filter screw in.

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