got an engine

[Rotore]

Ok i got a 4hp briggs & stratton engine here today. unlike the other engines this one starts but it has a rough idle then dies. any idea of what it could be?

other then that its missing a couple things like the govener spring i think.

and lastly how can i get some more power out of it? i was thinking about replacing the carb with one of the other engines i had (6hp) and running a straight pipe instead of the muffler.

here are some pictures:

 

[EagleTalons]

Clean the carb, replace the sparkplug, and regap the coil. For Basics

For more power you can get an offset fly wheel key. (advanced timing) Take out the governor...for safety reasons. Less restrictive air filter. A header. The bigger carb might not work, because of the restrictive pipe leading over to the intake valve.

 

[Rotore]

Clean the carb, replace the sparkplug, and regap the coil. For Basics

For more power you can get an offset fly wheel key. (advanced timing) Take out the governor...for safety reasons. Less restrictive air filter. A header. The bigger carb might not work, because of the restrictive pipe leading over to the intake valve.

regap the coil?

offset flywheel key?

sorry but i'm kinda new to small engines dude

 

[Kaptain Krunch]

Gap the coil to factory specs, it means setting the coil to the right distance from the flywheel. You will need a set of feeler gauges for that.

Offset flywheel key will advance/retard your timing (you can set it either way) by being slightly offset so that the engine creates its spark slightly sooner or later during the combustion cycle.

 

[Rotore]

Gap the coil to factory specs, it means setting the coil to the right distance from the flywheel. You will need a set of feeler gauges for that.

Offset flywheel key will advance/retard your timing (you can set it either way) by being slightly offset so that the engine creates its spark slightly sooner or later during the combustion cycle.

thanks. but when i start it. it has a rough idle. any ideas?

 

[Kaptain Krunch]

thanks. but when i start it. it has a rough idle. any ideas?

I guess that you having been around long enough to know that when it comes to carbs i dont know ****...maybe affair_driven can help, he seams to know what hes doing.

 

[Rotore]

I guess that you having been around long enough to know that when it comes to carbs i dont know ****...maybe affair_driven can help, he seams to know what hes doing.

ehhh dont go emo... it was just a question...

 

[Kaptain Krunch]

emo? ... i guess its hard to tell a joke over the internet, im just saying i really dont know anything when it comes to carbs. and that Affair_Driven (member here) seams to know his way around carbs pretty well (he's helped me with carb problems before).

 

[Rotore]

emo? ... i guess its hard to tell a joke over the internet, im just saying i really dont know anything when it comes to carbs. and that Affair_Driven (member here) seams to know his way around carbs pretty well (he's helped me with carb problems before).

lol sorry about that and yes it is a bit difficult

 

[Rotore]

well i played around with the engine and noticed that it was burning fuel quick and it didnt run for 5 mins so my best guess at the moment is the air/fuel mixture. i'm guessing there is some way to adjust it right? problem is i dont know how so any advice is appreciated guys..,.. here are a few more piks:

 

[Kaptain Krunch]

Like i said i dont know much but i know there should be an adjustable needle on the carb.

 

[Affair_driven]

Is air cleaner clean?
Fresh gas?
Spark plug clean and gapped?
What is color of spark plug insulator?

 

[THE HUNTER]

your planning on running a straight pipe on your mower? sure it will let it breath better, but wont your neighbors kinda dislike that? lol
if that engine has a pipe thread in the exhaust (most likley 1/2") try getting a muffler with a 3/4" thread on it, and use a pipe adaptor to put it on the mower.
it will allow the exhaust to escape easier, but still keeps the neighbors from getting mad lol.

other ways to get more power/better performance would be to of course, keep your air filter clean. also clean the carbon out of the combustion chamber every 100 hours as Briggs rec commends.

change/re-gap the spark plug. disassemble and clean the carb and set the mixture needles and idle screw properly. when doing that, make sure the rubber gasket/diaphragm between the carb and fuel tank is nice and soft, if its hard, you need a new one.

reset the gap between the flywheel and coil armature. clean and adjust breaker points, (but i highly doubt this engine uses breaker points)
and other basic maintenance like keeping the cooling fins free of grass and other debris, and always changing the oil when needed. always use fresh, clean gas.

arrow #1 is pointing at the coil.
arrow #2 is pointing at the armature.
and #3 is the flywheel nut lol

to adjust the gap of the armature, rotate the flywheel so the magnets are away from the armature. loosen the bolts holding the armature/coil assembly down enough for it to slide around a little. then move the armature/coil as far away from the flywheel as it will go, lightly tighten one of the mounting bolts. rotate the flywheel so the magnets are right under the armature, get your feeler gauge(s) of the specified thickness (get me an engine model number, and i'll tell you what you need) and put it between the armature and magnets, then loosen the mounting bolt, the magnets will pull the armature/coil assembly up to the feeler gauge, make sure the feeler gauge is between all the legs of the armature and the flywheel, then tighten the bolts down, carefully remove the feeler gauge. and yer done.

you should get a really nice hot spark after that.
(its pretty simple, when you actually do it lol)

cleaning/adjusting the carb (try to adjust first, if that doesnt work, then clean), changing the spark plug, and setting the armature gap should fix the rough idle prob.
thats usually all it takes, but the other stuff wont hurt lol


look up your owners manual on the Briggs site, that will usually tell you how to adjust the carb

 

[Rotore]

Is air cleaner clean?
Fresh gas?
Spark plug clean and gapped?
What is color of spark plug insulator?

took the air filter off then i first started it but the air filter is fine.

yes it has fresh gas.

havent taken the spark plug off yet i need to go pik up my tools tomorrow and the spark plug will be getting replaced with a new one tomorrow.

 

[Rotore]

your planning on running a straight pipe on your mower? sure it will let it breath better, but wont your neighbors kinda dislike that? lol
if that engine has a pipe thread in the exhaust (most likley 1/2") try getting a muffler with a 3/4" thread on it, and use a pipe adaptor to put it on the mower.
it will allow the exhaust to escape easier, but still keeps the neighbors from getting mad lol.

other ways to get more power/better performance would be to of course, keep your air filter clean. also clean the carbon out of the combustion chamber every 100 hours as Briggs rec commends.

change/re-gap the spark plug. disassemble and clean the carb and set the mixture needles and idle screw properly. when doing that, make sure the rubber gasket/diaphragm between the carb and fuel tank is nice and soft, if its hard, you need a new one.

reset the gap between the flywheel and coil armature. clean and adjust breaker points, (but i highly doubt this engine uses breaker points)
and other basic maintenance like keeping the cooling fins free of grass and other debris, and always changing the oil when needed. always use fresh, clean gas.

arrow #1 is pointing at the coil.
arrow #2 is pointing at the armature.
and #3 is the flywheel nut lol

to adjust the gap of the armature, rotate the flywheel so the magnets are away from the armature. loosen the bolts holding the armature/coil assembly down enough for it to slide around a little. then move the armature/coil as far away from the flywheel as it will go, lightly tighten one of the mounting bolts. rotate the flywheel so the magnets are right under the armature, get your feeler gauge(s) of the specified thickness (get me an engine model number, and i'll tell you what you need) and put it between the armature and magnets, then loosen the mounting bolt, the magnets will pull the armature/coil assembly up to the feeler gauge, make sure the feeler gauge is between all the legs of the armature and the flywheel, then tighten the bolts down, carefully remove the feeler gauge. and yer done.

you should get a really nice hot spark after that.
(its pretty simple, when you actually do it lol)

cleaning/adjusting the carb (try to adjust first, if that doesnt work, then clean), changing the spark plug, and setting the armature gap should fix the rough idle prob.
thats usually all it takes, but the other stuff wont hurt lol


look up your owners manual on the Briggs site, that will usually tell you how to adjust the carb

screw my neighbors i dont like them either

 

[Affair_driven]

Sounds like a faulty diaphragm.
Carb kits are cheap and easy to install. Just go slowly. Don't lose the spring.
No adjustments on that carb.
Coil should be set at .010", but highly unlikely that is affecting anything. I doubt it needs adjustment.

 

[THE HUNTER]

Sounds like a faulty diaphragm.
Carb kits are cheap and easy to install. Just go slowly. Don't lose the spring.
No adjustments on that carb.
Coil should be set at .010", but highly unlikely that is affecting anything. I doubt it needs adjustment.

yeah, keep an eye on that little spring! i almost lost mine a few times lol

Briggs does reccomend (in the repair manual i have) different gap setting for different engines, though .010" is the most common listed in the range for all single cylinder, L-head aluminum block engines (made after 1981). it will be fine for your engine.
that is unless the armature has 3 legs instead of the common 2, then use .012"-.016" gap

 

[Rotore]

Sounds like a faulty diaphragm.
Carb kits are cheap and easy to install. Just go slowly. Don't lose the spring.
No adjustments on that carb.
Coil should be set at .010", but highly unlikely that is affecting anything. I doubt it needs adjustment.

thanks guys. now where can i get a carb kit?

 

[THE HUNTER]

thanks guys. now where can i get a carb kit?

yer welcome lol

and any good lawn and garden, or small engine repair place will either have them in stock, or be able to order them for you.



yeah, im not too crazy bout my neighbors either, but mowing all day with a straight pipe is bad for yer hearing lol
i have a stock [replacement] muffler on my 3.5hp Briggs and it works fine for me.

 

[Rotore]

yer welcome lol

and any good lawn and garden, or small engine repair place will either have them in stock, or be able to order them for you.



yeah, im not too crazy bout my neighbors either, but mowing all day with a straight pipe is bad for yer hearing lol
i have a stock [replacement] muffler on my 3.5hp Briggs and it works fine for me.

lol cant be as bad as a rotary with a straight pipe... but even with the muffler it sounds bad ***.