Engine smokes

slomo

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Stop using the mower.

Fix the carb. Pressure test the needle and seat to 7psi. Should hold for 30+ minutes with a WET needle. If not get a rebuild kit or a new OEM carb. Stay off Amazon and Ebay for carbs.




Once the carb is fixed, dump the oil a couple times PRIOR to mowing.
 

Knocking Oppy

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float leaked gas into the motor oil, thinned it ... big time . gasoline is not a lubricant. lucky if didnt spin weld the rod to the crankshaft... spin/friction welding. they put tool joints on drill pipe that way. tool joint, M or F end, is machined. pipe is made in plug mill. pipe is held. machined tool joint made up in fixture, spun at high speed and the 2 shoved together... friction welding. excess mushroom is machined off... x rayed for flaws and good to go.

some ppl put a fuel shut off valve in the fuel line and at the end of the day shut the valve off and let the motor / carb run out of gas... DONT FORGET TO TURN THE KEY OFF OR WILL DRAIN THE BATTERY!!! got to remember to turn the fuel on before starting the motor.... hopefully, will figure that one out before running the battery to nothing. battery maintainer makes batteries last a good long time... sometimes.

write on the dash with marker (its not a lexus/mercedes, its a mower) TURN ON GAS TO START.. TURN OFF GAS AT END OF DAY. .. let carb run out of gas and TURN KEY OFF.

the problem is worse with the gas tank above the carb as gas will "gravity" thru the leaking needle/seat in the carb and keep "gravitating" thru the carb til... the crankcase is full and the gas tank is empty. that will leak to thrown rod in horizontal motor as it is an air pump. NOT A FLUID pump. overfilling engine with oil will blow it up, dont ask. thank you. change oil on LEVEL GROUND AND NOT IN THE DARK. simple enuf. (sigh) lessons learned.

oil change might prolong its life...20-50 oil... with ~25% STP OIL TREATMENT to thicken the oil. most ppl dont use mower in winter so dont need 0w-20 for those MINUS 20* morning starts. black smoke is excess gasoline/burning RICH. blue grey smoke is oil burning.

i have problems starting my little push mower, primer bulb never did work right, even new. so i got 500 ML RC Gas car/truck/truggy fuel bottle, take off air cleaner, dribble gas in the carbs throat, put air cleaner back on... starts 2 pull... not 5000th pull or i have heart attack/stroke/fall over...curb it, whichever occurs first. a big puff off BLACK SMOKE out the exhaust and away it goes.

CHECK OIL BEFORE EACH RUN OF DAY sticker on E bay. actually CHECK OIL BEFORE STARTING to put on prominent place on machines as most ppl just cannot do it and... i get them. too worn out to rebuild, but i rebuild them anyway just to see if i can do it. they run but ... 60 PSI running compression, not 110-130 PSI ? Model T ran on ~60 PSI running compression... 4 to 1 compression ratio... down on power, but will run the cheapest gasohol and not worry abt pre ignition.

my latest Briggs rebuild... scored cyl/piston from... no oil changes... no oil? sanded cyl/piston skirt, cleaned it out, new rings (shd have replaced rod but it seemed ok?). new gaskets/seals off e bay. piston rock in cyl is noticeable. 15-40 wm diesel oil started/runs ok... PISTON SLAP from piston wobbling around in cyl as piston/cyl is worn (out). 20-50 oil with 30% STP oil treatment... still big time piston slap. sounds like rod knock but isnt. might last... ??? it will foul the plug with oil so will have to clean plug or put in new ones from time to time as the plug gets coated with oil and wont fire. $3 plug at WM. it will run til it wont and that will be that. 50 hrs of limited use?

read can use up to 80% LUCAS oil stabilizer (liquid grease) in motors and differentials/transmissions/xfer cases for BADLY WORN machines??? ok for warm weather machines as LUCAS/STP is still fluid above... 40*F? below 40*F? need 5 mins to get the liquid grease to be more fluid.
 

sgkent

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yes. Having the carb rebuilt professionally would be wise too. As to the remark someone made on the head gasket. You can have more than one problem causing grey smoke, so if fixing the carb doesn't solve it completely have the head gasket checked too. I find that the heads on all the air cooled equipment I have owned need to be checked for torque once in awhile.
 

slomo

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Just like any head gasket, needs retorqued at least once. Aluminum heads more often.
 

zippy2

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So I replaced the carb with an OEM B&S. Still smoking. Must be the head gasket? If so, I'll have to get a pro to repair as I am not capable of doing it.
 

slomo

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Is this an Intek engine? If so they love to toss some head gaskets.

Might post up your engine numbers.
 

bertsmobile1

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So I replaced the carb with an OEM B&S. Still smoking. Must be the head gasket? If so, I'll have to get a pro to repair as I am not capable of doing it.
You are capable of replacing the head gasket it is an easy job
A first timer should allow a full day
Techs do them in about 1 hour , the total scheduled service fee for the job is just short of 1 hour
I charge out 2 hours regardless of how long it takes
The gaskets are not expensive and the only special tools needed are a small tension wrench because the bolts are tightened to around 25 ft lbs and a sheet of glass with some wet & dry about 400 grit .
 

zippy2

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You are capable of replacing the head gasket it is an easy job
A first timer should allow a full day
Techs do them in about 1 hour , the total scheduled service fee for the job is just short of 1 hour
I charge out 2 hours regardless of how long it takes
The gaskets are not expensive and the only special tools needed are a small tension wrench because the bolts are tightened to around 25 ft lbs and a sheet of glass with some wet & dry about 400 grit .
Thanks for the encouragement, but I'm hauling it off today to a pro. I don't have any of the specialized tools necessary for the job.
 

slomo

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Sockets and or wrenches?

Might look into a lawn service if you lack any tools.
 
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