Export thread

Hello folks, thanks for letting me on your forum and thanks in advance for any help offered.
So the wife was trying to be helpful and mow the lawn. She grabbed the can we had just filled with diesel the day before for our boats Yanmar and filled the Briggs 17.5 in our Huskee mower. She said it made a round or two in the yard before it started making funny noises and quit.
Took me a minute to figure it out, as a half and half diesel / gasoline mix is sort of hard to peg until you get a little on your fingers ...

Anyway.... after a few hours trying to get her going, I went and picked up a new carb. She was smoking and back firing and would not run. After new carb... same thing. I kept thinking that it was diesel still in the system until after two days of fooling around, I have figured out that it’s blowing oil.
So what happened? I expected it to smoke for a bit and even a carb replacement, but what went wrong for the motor to now be getting motor oil into the fuel mixture? What broke and why ?
Thanks again. Look forward to the thoughts on this one.

Gravity fed carb? Did you check oil level? is it high? Diesel is a lube - could have slipped by the needle/seat and landed in the crankcase.

dougand3 said:

Gravity fed carb? Did you check oil level? is it high? Diesel is a lube - could have slipped by the needle/seat and landed in the crankcase.

Click to expand...

Oil in crank case looks good. No smell of fuel and level is right.
When I pull the plug and turn it over, I can hold my hand in front of the hole and it is definitely motor oil being pushed out in the fuel mist.

First, pull the plug and see if it will spin freely.
If so, change and gap the plug. Then, install.
Second, pull the tank and empty.
Third, make sure the fuel lines are clear of liquid.
Fourth, install new fuel filter.
Fifth, clear the breather hose.
Sixth, change the oil.
Finally, put some high octane in it and give it a whirl.
If your air filter is wet, you will need a new one.
I almost forgot. Drain the carburetor bowl.

MParr said:

First, pull the plug and see if it will spin freely.
If so, change and gap the plug. Then, install.
Second, pull the tank and empty.
Third, make sure the fuel lines are clear of liquid.
Fourth, install new fuel filter.
Fifth, clear the breather hose.
Sixth, change the oil.
Finally, put some high octane in it and give it a whirl.
If your air filter is wet, you will need a new one.
I almost forgot. Drain the carburetor bowl.

Click to expand...

Yes, already drained tank and installed a brand new carburetor.
Going to change the oil this morning and see if that helped

thanks.

Portajon said:

Yes, already drained tank and installed a brand new carburetor.
Going to change the oil this morning and see if that helped

thanks.

Click to expand...

I hope that you cleared the fuel lines.
Installed a new fuel filter?
Drained the bowl on the new carburetor? There probably wasn’t that much wrong with the old one. Could have been cleaned.
Installed a new spark plug?
Did you clean the vent tube going into the valve cover?

MParr said:

I hope that you cleared the fuel lines.
Installed a new fuel filter?
Drained the bowl on the new carburetor? There probably wasn’t that much wrong with the old one. Could have been cleaned.
Installed a new spark plug?
Did you clean the vent tube going into the valve cover?

Click to expand...

The solenoid on the old carb bowl was cross threaded from the factory. A nice, long ribbon of monkey metal threads came out with it when I removed it to clean the bowl.
Something far more than the obvious went wrong. There is a hole in the piston or the rings went away .... I have back pressure and white smoke coming from the crank case vent tube and oil filler. I don’t know how long she ran it on the diesel / gas mixture but long enough for something critical to break. I’m thinking it got really hot.

Head gasket ? ..... I dunno, but gotta tear it down. This is a dang nice mower with little wear and use and I’m just sick about it.

There you go!

Confirmed blown head gasket. Order a couple spare gaskets. That engine is a know head blower.

Local shop, B&R Lawn Equipment, Plymouth, NC had the gasket in stock, $6. Had it back together and running before lunch.

Whew ... saved my mower. Now to teach the wife to always give a little sniff to what’s in the can before you assume ....

Portajon said:

Local shop, B&R Lawn Equipment, Plymouth, NC had the gasket in stock, $6. Had it back together and running before lunch.

Whew ... saved my mower. Now to teach the wife to always give a little sniff to what’s in the can before you assume ....

Click to expand...

That’s great news.
I hope that you have different colored fuel cans.

Fun

MParr said:

That’s great news.
I hope that you have different colored fuel cans

Click to expand...

Funny you mention the cans ...

I just bought a new compact tractor / loader / back hoe and was telling the wife I needed to get a couple yellow cans for diesel. That conversation came up while I was filling a red 5 gallon can with diesel to take to our boat. Our boat and tractor both have Yanmar diesels. The very next day I bought two yellow cans for the tractor but the red one still had maybe a half gallon of diesel in it after topping off the boat tank. I mean ... she had literally carried that can onto the boat the day before. And there were TWO other cans beside it, both with gasoline n them. Even not paying attention and forgetting the conversation we had just a few days ago she still had a two out of three blind chance to grab a can that had gas ....

But yeah ... diesel only goes the yellow cans from now on.

Great job. Glad you had the skill to do it yourself.

The wife was just helping you refine your small engine repair skills.

This happened to my dad about 30 years ago, A gas station accidently had diesel mixed with there gasoline. He drove it 7 miles home, the car would not start. I found that all the valves sticking open. Let it sit over night they would close. One revolution of the crank the next day they would hang open again. I pulled the head, (inline 6 cyl). Took it to the machine shop, they knew right away what the problem was and told us about the mix up at the gas station. I would check valve stems for build up of crude. I know it not a lawn mower, just thought I would pass a little info along.

I had that once and a new spark plug did the trick.

You should have immediately completely drained Fuel tank and lines and Float bowl. Replaced Fuel Filter.. Replace Spark Plug. Refill with a gallon of Fresh Gasoline. Bought flowers for Wifey. She owes you now. The diesel would not have harmed anything in the Carb.. Strange the head gasket blew. Good luck.

Rich M. said:

Great job. Glad you had the skill to do it yourself.

The wife was just helping you refine your small engine repair skills.

Click to expand...

"The wife" . . . .funny!

hope the alloy head wasn't too warped, i used to have a sheet of glass with wet n dry sand paper stuck to it & rub the head back & forth over it to try get a smooth/even surface, as mentioned previous - it may blow another gasket

Portajon said:

Local shop, B&R Lawn Equipment, Plymouth, NC had the gasket in stock, $6. Had it back together and running before lunch.

Whew ... saved my mower. Now to teach the wife to always give a little sniff to what’s in the can before you assume ....

Click to expand...

How about write on the can with a Sharpie what is in the Can ???

Stokdgs said:

How about write on the can with a Sharpie what is in the Can ???

Click to expand...

Yeah, like my diesel in a denatured alcohol can marked "DIESEL" in Sharpie. The two-stroke gas is in a completely unmarked red can...

Portajon said:

Fun


Funny you mention the cans ...

I just bought a new compact tractor / loader / back hoe and was telling the wife I needed to get a couple yellow cans for diesel. That conversation came up while I was filling a red 5 gallon can with diesel to take to our boat. Our boat and tractor both have Yanmar diesels. The very next day I bought two yellow cans for the tractor but the red one still had maybe a half gallon of diesel in it after topping off the boat tank. I mean ... she had literally carried that can onto the boat the day before. And there were TWO other cans beside it, both with gasoline n them. Even not paying attention and forgetting the conversation we had just a few days ago she still had a two out of three blind chance to grab a can that had gas ....

But yeah ... diesel only goes the yellow cans from now on.

Click to expand...

Some gas stations will turn the pump off if you use the wrong colored can around here.

That would be a costly repair if you gassed a marine Diesel engine LOL.

Portajon said:

Local shop, B&R Lawn Equipment, Plymouth, NC had the gasket in stock, $6. Had it back together and running before lunch.

Whew ... saved my mower. Now to teach the wife to always give a little sniff to what’s in the can before you assume ....

Click to expand...

Hope you used a piece of plate glass and some 220 and 600 grit wet/dry paper. Needed to flatted the head and block area. No doubt they are warped. And obviously torque the head bolts back to factory specs.

And while you are at it, clean those filthy engine cooling fins and engine block yearly. It's in your engine manual for all mower engines.

Gord Baker said:

You should have immediately completely drained Fuel tank and lines and Float bowl. Replaced Fuel Filter.. Replace Spark Plug. Refill with a gallon of Fresh Gasoline. Bought flowers for Wifey. She owes you now. The diesel would not have harmed anything in the Carb.. Strange the head gasket blew. Good luck.

Click to expand...

I do not understand the math on how incorrect filling with diesel = blown head gasket. Seems like it would just not ignite, as this isn't natively a high-compression engine.

I remember when my neighbor’s wife was going to be helpful and use his new Stihl back-pack blower. She filled it with straight gasoline without any oil. It didn’t run long before it died. Needless to say, he was not a happy camper.

Oh, and I made the mistake of letting him borrow my chainsaw. He didn’t return it for a while so I went to his home and retrieved it from his wife. It was taken apart and some parts were missing. I have no idea how or why he tore it up. I didn’t say anything to him about it and he never asked to borrow any tools again.

Lord_Cavendish said:

I do not understand the math on how incorrect filling with diesel = blown head gasket. Seems like it would just not ignite, as this isn't natively a high-compression engine.

Click to expand...

The diesel, m'lord, would be ignited by the gasoline. How this could contribute to blowing a head gasket, I dunno.

Tdj2591 said:

Oh, and I made the mistake of letting him borrow my chainsaw. He didn’t return it for a while so I went to his home and retrieved it from his wife. It was taken apart and some parts were missing. I have no idea how or why he tore it up. I didn’t say anything to him about it and he never asked to borrow any tools again.

Click to expand...

A loan without collateral is a gift.

Portajon said:

View attachment 58467

Click to expand...

May I add,before you beat your wife up too bad for her mistake,these OHV Intek Briggs engines are prone to blowing the head gasket right there where yours did. That's why the mower shop had the gasket in stock. I'd bet they have a drawer full of them.
There is a possibility that this had nothing(really) to do with the diesel in the fuel. Usually,diesel in a gas engine just won't ignite and the engine will stall. Gasoline in a diesel is a whole different scenario,but I digress. There is a high possibility that this was coming,regardless. I've had this very same gasket failure happen to me more than once for no good reason. I would bet others will bear me out on this.

Richard Milhous said:

A loan without collateral is a gift.

Click to expand...

Boy,that how it usually works out,it seems!

Friend of mine went to Lowes and bought a new Husqvarna riding mower. Takes it home, my friend was a trucker, and fills it with diesel accidentally out of a jug he had setting around. Mower won't run, so he hauls it back to Lowes and they give him another one. He said on his way home it dawned on him what he had done. Said, man did I feel stupid. I should have went to Lowes to see if they had any returned mowers for sale cheap, but I didn't really need one at the time.