B&S 18HP Intek

[ATS-V]

I have a 3 year old Intek single cylinder that see's ~50 hours a year. I have been changing the oil and filter yearly with M1 5w30 and have had very little if any oil consumption. I week ago I was mowing on a hot day and after about 20 minutes I got a big puff of oil smoke and it almost stalled, from that point on it has been burning oil. I haven't determined how much yet, but enough to have that annoying smell and visible smoke.

Is anyone familiar with this engine model and what it possibly could be causing the issue?

 

[JTK]

Maybe it was slightly overfull, got good and hot and that added crankcase pressure blew some oil into the combustion chamber? Vertical shaft engines are sensitive to oil level. Parking them or mowing nose down (cylinder head lower than sump) can result in a blue cloud as well. If it's not blowing smoke constantly, everything is probably A-OK. Just needs some run time to clear the exhaust.

Joel

 

[jsharp]

How many total hours on the engine? There are plenty of reports on the net of the Intek motors having major problems in under 100 hours. Excessive oil consumption is high on the list...

 

[ATS-V]

No it's blowing contantly now.

I changed the oil & filter this weekend to rule out oil level and/or diluted oil. But that wasn't it.

I'd estimate it has about ~150 hours on it.

 

[Bill Kapaun]

Head gasket.
Remove the valve cover, start it and you'll see "mist" blowing out on the push rod side of the gasket. Have a rag handy and wear old clothes!

 

[ATS-V]

Quote:

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Head gasket.
Remove the valve cover, start it and you'll see "mist" blowing out on the push rod side of the gasket. Have a rag handy and wear old clothes!

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I was thinking head gasket, because after the 2nd use, I noticed oil was dripping down dip stick tube. Which to me meant that cylinder pressure was entering the crankcase. Either that or cracked cylinder or cylinder head.

 

[ATS-V]

Anyone know where it's best to get the head gasket? Anyone have a repair manual they can send me?

Engines Model: 31P777

Thanks

 

[Bill Kapaun]

699168 head gasket is about $5-6 on line. It'd probably be cheaper to go to your local dealer when you add in S&H.

 

[ATS-V]

Thanks for your help Bill

 

[Bill Kapaun]

Did that fix the problem?
IF you did change it, are you aware the valves are set with the piston a 1/4" past TDC?
Just checking-

 

[ATS-V]

I haven't fixed it yet, since it's still running and I've been busy with family stuff.

Can you explain further? 1/4'' past TDC. From what I've been able to find on the net valve lash is 0.003-0.005 intake and 0.005-0.007 exhaust, is that correct? How long would you estimate this to take?

 

[Bill Kapaun]

When at TDC, the compression release "bump" on the cam interferes with correct valve adjustment.
Use something like a wooden pencil or similar into the spark plug hole (TDC) and touch the piston. Mark the pencil and then place another mark on the pencil 1/4" away. Now slowly rotate the engine so as the piston starts to go down, the second mark aligns where you made the first mark.
Your lash #'s match what I've seen.
The job shouldn't take too long IF you have the proper tools. A couple hours should do it, working methodically.
You can remove the valve cover and see what other tools are required BEFORE you continue. Maybe a Scotch Brite pad or similar would be handy to clean off and specks of gasket material that wants to stick.

 

[pbm]

My new 18 hp Craftsman rider has the 18 hp Intek model # 31H777. Is this the same engine? Is there anything (maintanence wise) that I can do to prevent this happening?

 

[Bill Kapaun]

For all intents and purposes, they are the same engine. You'd have to download the IPL from Briggs and compare all the parts to find the differences. It might be as subtle as the paint color, HP decal or???
The block, crank, head, sump, piston & carb are the same part#'s. I wasn't inclined to check any more parts.

 

[pbm]

Bill: I plan on changing my oil more frequently than every 50 hours but aside from that is there anything else or are these engines 'throwaways'?

 

[ATS-V]

Funny that pbm posted his model number. I thought that mine was a P but noticed last night the the model number is actually 31H777.

 

[ATS-V]

pbm,

It seems that these engines have head gasket issues. Other than that they seem to run quite well. Even with the shot gasket I continued to mow for several weeks. Mines on it's 4th season.

The head gasket was pretty simple, even the valve adjustment was straight forward. I bought the "valve gasket kit" which contained the head gasket, rocker gasket and a couple other small ones since it was only a couple dollars more that the head gasket itself. Total cost w/tax $9.80.

 

[Bill Kapaun]

Did you get it running OK/
If you did, you may want to recheck the torque on the head bolts, after a "heat cycle" or 2.

 

[pbm]

97GTP: Thanks for the info. Do you have a part # for the
'valve gasket kit'? Did you find a repair manual online? Thanks again.

 

[ATS-V]

Bill,

Yep got it running, nice not to be blowing oil smoke again. I might re-check the torque.

pbm,

Head Gasket: 699168
Engine Gasket: 697191
Valve Gasket: 690190

I only ended up using the head gasket, the valve gasket came off clean and I didn't need the other gaskets. Like I said it was only a couple dollars more. The procedure for the valve adjustment was sent to me by someone online, I could send it to you if you'd like.