Lawn Mower White Smoke - Saturn Forum - Saturn Enthusiasts Forums

Off Topic A place for you car junkies to boldly post off topic...

Lawn Mower White Smoke

Reply

 
 
 
  #1  
Old 10-02-2018, 02:51 AM
derf's Avatar
Super Moderator
Thread Starter
Join Date: Jul 2005
Location: My Saturn ;)
Posts: 7,358
Default Lawn Mower White Smoke

Hey folks,

I was cutting my lawn this weekend. About half way through, after emptying the bag, I pulled the cord and was welcomed with a plume of white smoke which reduced itself after 20 sec to a faint but steady output of white smoke.
Mower ran fine except for the smoke. Sopped for a couple minutes, restarted, same deal.

Ok, oil burning in the cyl (4 stroke engine)
'
If had it temporarily smoke after running over some dips and valleys on my property, splashing oil into the cylinder and such. But it went away after 15 seconds.
Oil level was is reading as full
Packed it in for the day.

Started it this afternoon. Zero smoke at startup, but after 10 seconds of running, the faint steady smoke began to appear so I shut it off again.

Only 1.5 years old, Briggs and Stratton motor -- still under warranty, thankfully.

Thoughts?

Beginning of a head gasket leak?
Breather clogged?
cracked head or block?
ring issue?

Thanks
 
Reply With Quote
  #2  
Old 10-02-2018, 08:26 AM
Rubehayseed's Avatar
Senior Member
Join Date: Jul 2011
Location: Lake Wales, FL
Posts: 3,572
Default

Perhaps some carbon on the intake valve, derf? For some reason, some oil is definitely getting into the cylinder. I'd try a little Seafoam in the gas tank to see if that helps. Maybe an ounce or two based on what HP Briggs it is. Someone else may have a better suggestion.
 
Reply With Quote
  #3  
Old 10-02-2018, 09:13 AM
02 LW300's Avatar
Super Moderator
Join Date: Apr 2015
Location: Willamette Valley, Oregon
Posts: 1,088
Default

Probably oil getting into the air cleaner. Crankcase could be slightly over full due to the float sticking. Crankcase vents directly into the air cleaner. Almost the end of the season, thankful for warranty.
 
Reply With Quote
  #4  
Old 10-02-2018, 09:21 AM
derf's Avatar
Super Moderator
Thread Starter
Join Date: Jul 2005
Location: My Saturn ;)
Posts: 7,358
Default

Thanks, Rube.

I find it interesting that there is zero smoke at startup. It is an OHV engine, so if oil was leaking past the valve guide seal I would think it would start burning oil as soon as the motor got up to speed, since it is a splash type oil distribution system.
I also find it difficult but not impossible for the head gasket to be failing, as cooling down should not make it seal again, although if it is a miniscule leak, I guess the thermal expansion of the metals would open iup the seal as the mower heats up.
It runs fine so it has good compression (I assume), though if the head gasket leak was slight, I might not see it in a compression test -- dunno, plus I don't know what the beginning compression for these engines is, though I could look it up.
Suppose it could be a ring issue, but that would lead to reduced compression which does not seem to be an issue

I fear it is a hairline crack in the head or block that, as the engine warms, opens up to a fixed separation at a given temperature, thus a fixed amount of oil is getting into the cylinder per unit time.

I need to go out and see if I smell gas in the oil and vice versa.

Don't know where the breather is but I assume it vents crankcase pressure just like an always open PCV -- will look into it more.

Had dream last night I was cutting with it and hit a bump and turned upside down and a car head gasket milkshake poured out of the unit. Not possible here but tells you where my subconscious is.

Air filter is dry for now.
 
Reply With Quote
  #5  
Old 10-02-2018, 09:30 AM
derf's Avatar
Super Moderator
Thread Starter
Join Date: Jul 2005
Location: My Saturn ;)
Posts: 7,358
Default

Cross posted.

Air cleaner is dry.

Float sticking would dump gas into the oil, yes? Thereby overflowing the mixture into the cyl?

I will go smell oil for gas and report back.

I have a 20 year old snowblower and a 22 year old mower, both craftsman w briggs n strattons -- neither has ever let me down, even with abusively long oil change intervals.
MAkes ya wonder.

What makes the float stick? Varnish? I use Stabil on every drop of gas thatgoes into my gas powered equipment and have for 22 years. Never 1 problem sarting up next season without drain. Plus stabil fights varnish formation, so even stored with gas in it, it's not running while stored so shouldn't make any difference. So far my longest preserved gas that still works is 2 years. Haven't tried past that. Also use ethanol<10% per mfr's recommendations.

Thanks
 
Reply With Quote
  #6  
Old 10-02-2018, 09:37 AM
derf's Avatar
Super Moderator
Thread Starter
Join Date: Jul 2005
Location: My Saturn ;)
Posts: 7,358
Default

Oil doesn't smell right. Not burned. HINT of gas kinda sorta there, but that might be me willing it to be so in my mind.

We'll go with carb float stuck and pushing gas into oil and overflowing crankase oil into cylinder.

This is one of those "never need to change the oil" mowers where you supposedly add n go without ever doing a full change. Seems designed to trash your mower in 5 years so you have to buy a new one. I will change the oil but not until the warranty claim is over. Actually they will do it as part of the carb replacement.
 
Reply With Quote
  #7  
Old 10-02-2018, 04:17 PM
02 LW300's Avatar
Super Moderator
Join Date: Apr 2015
Location: Willamette Valley, Oregon
Posts: 1,088
Default

I have been buying ethanol free premium for all my small engines.
 
Reply With Quote
  #8  
Old 10-02-2018, 05:41 PM
derf's Avatar
Super Moderator
Thread Starter
Join Date: Jul 2005
Location: My Saturn ;)
Posts: 7,358
Default

Where do you acquire said petrol?
 
Reply With Quote
  #9  
Old 10-02-2018, 10:51 PM
02 LW300's Avatar
Super Moderator
Join Date: Apr 2015
Location: Willamette Valley, Oregon
Posts: 1,088
Default

It is available at at least one station in every town here. We have many lakes and the boats run much better on ethanol free fuel. It may be an Oregon thing.
 
Reply With Quote
  #10  
Old 10-02-2018, 11:23 PM
derf's Avatar
Super Moderator
Thread Starter
Join Date: Jul 2005
Location: My Saturn ;)
Posts: 7,358
Default

No, it's everywhere. I hear rumors that I've never chased down. I was wondering if it would be more likely to be found at a station that sells the 100 octane stuff,......
Dropped off lawn mower today for a warranty claim.

A Husqvarna 21" AWD w the bigger back wheels does NOT fit in the trunk of a 97 SC2

But it does fit on the front seat w the back laid down
 

Last edited by derf; 10-02-2018 at 11:26 PM.
Reply With Quote
Reply
 
 
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
cptmiker
Saturn S Series Sedan
8
04-25-2018 06:01 PM
derf
Off Topic
6
08-13-2015 06:19 PM
slipp96
Saturn S Series Sedan
4
07-18-2013 05:59 AM
PhantomLover007
Saturn L Series Sedans & Wagons
1
05-23-2007 08:41 PM
F4iGuy
Saturn S Series Sedan
6
11-22-2006 09:43 PM


Thread Tools
Search this Thread