i have a 1979 8hp briggs engine (191707) that lets the biggest cloud of white/blue smoke when you open her up that you could ever imagine due to burning oil. i was just wondering if this is a problem or that i should just wait till it starts to start hard. but i was just wondering around how much it would cost to rebuild the engine. i know i will have to get it bored out .010 oversize and buy the .010 oversize rings and piston but around how much would this cost to do and am i missing anything else to put in the thing.(i live in canada). thanks

hope this helps.

White or Blue/Gray Smoke

Most people automatically associate this as a sign of a major engine problem, which is not always true. While there are definite reasons for concern, this symptom or problem is not always as bad as it appears. In fact, there are several causes for this problem that are relatively simple to troubleshoot and correct. Before you assume the worst, take a look at some of these potential causes along with my recommendations for each.

1. The engine has been overfilled with oil, or the oil has been contaminated with water or fuel, causing an overfilled condition. (Check the oil level, and make sure it is not contaminated.)

2. Diesel fuel, or 2-Cycle oil/fuel mix has mistakenly been added or substituted for gasoline. (Take a fuel sample in a clean container and verify that it's pure, fresh gasoline.)

3. The engine or equipment has been tipped up the wrong way, causing oil to enter the combustion chamber, carburetor and or exhaust system. This is a very common cause for this problem. (If you have recently tipped the engine for any reason, chances are good that this will be the cause. )

If the exhaust system or carburetor have been filled with oil, the engine will eventually stop smoking unless the air filter has become saturated with oil. If it has, the engine may not start or will run poorly until you clean or replace the air filter. BE SURE TO CHECK THE OIL LEVEL BEFORE RE-STARTING!


*Note - All of the following will require at least a partial disassembly or special tools to verify.

4. The crankcase breather(s) are malfunctioning.


5. Leaking crankcase gaskets or seals are causing the engine to lose crankcase vacuum, and allowing the oil to be "pulled" into the combustion chamber.


6. Oil is leaking past worn or damaged valve stems, valve stem seals, or valve guides.


7. The oil ring(s) and/or cylinder bore are worn or damaged.


Refer to the repair instruction manual or take the machine in for professional service.

well i ordered a gasket for the crankcase because it is spitting out oil and i got a new gasket ordered for the crankcase breather cause that gasket is broke,, would this make it smoke like it does. thanks for your reply

Yes a worn out breather would cause it... does it have a dipstick? Make sure thats good and sealed tight, Top and bottom.

i can move the dipstick up and down,, the breather works i checked that,, i got new beather gaskets and crankcase gaskets comin monday.. its making a popping sound from the muffler and i know that the carberator need to have a kit put in it,,, and one more thing i put the piston back in and does it matter were the splitt in the piston rings are around the piston,, thanks

As long as the gaps aren't lined up... as for the dipstick, you can move it up and down? I have basically the same year engine... theres that tab with one tiny bolt that holds it down.. I used a spare peice of targon fuel line to take the slack up so it seated down good... for the popping, you probablly just need to adjust the carb.

i got the dipstick fixed and im waiting for the gaskets but i tried ajusted the carb a little and it wont get any better what can i do about it. would the popping have anything to do about the oil getting pulled in the head where the crank case gasket leaks. one other thing how hard is it to replace the seals on each end of the crank and how do you do it and do you put the crank in first and then the new seals or the seals in and then the crank,, thanks for your replys

Seals in first... they aren't too hard. Just make sure they are lubed and tap em in. The popping could be from the valves then, the popping has nothing or should have nothing to do with the oil. The valves just need some adjustment, and probablly a complete valve job.

i had planned on a complete valve job after i got everything else fixed up, i know i need valves, valve springs and retainers to hold the valve spring but what else will i need to do or get. the seal under the flywheel is the one giving me the trouble, the oil gets sprayed everywhere. thanks for your replys

Pry the ring out, take note on how its coming out, and pry the seal out carefully and replace it, and tap it back in.

well i gonna start to tear her a part today if i get the parts, thanks for your replys

i got all the new gaskets and seals in the other day and it does not smoke no where near as bad as it use to. but i have another question,,, instead of boring it out .010 oversize can i just hon it out and put a new set of standard rings in it,, the piston and bore dont look to be in bad shape at all,,,and as for the poping coming out of the exhaust i cleaned the carb and it no longer does that,, thanks

You should be fine doing that. As for shape though, you feel no wear ridge and or scratchmarks up and down on the bore?

no, there are no scratches in the bore. i can take my fingernail and scrape around the bore and felll no makes at all, just very very very slight ones. so if i hon it out and put new standard rings in it, it wont burn oil anymore right,, thanks for the reply

You should. Can you see any cross hatch left?

what do you mean by cross hatch

Cross hatch, its done at the factory or when rebuilding a engine, tiny criss cross scratches are put up and down the bore for improved oil flow.

yes i can see the cross hatch,, so should i go ahead with buying a standard set of rings and honing it out and will this stop it from burning oil. thanks

Yep, if you see some cross hatch, the bore shouldn't be too worn out to begin with.

guess what,, all the things i done and i thought the breath was ok,, it wasn't. i thought that the thing in the middle of the breather on the side thats in the engine was suposed to move alot until i took my other good engine apart and found that that wasn't loose like the other one.. changed it and now all it does is smoke when i go from idle to full throttle very fast, i guess its supposed to do this,(the other motor that i took the good breather from did this too) ,, thanks for your replys