Briggs Intek 20HP Using Oil

[Mr. Shamrock]

Yeah the spark plugs get sooty pretty quick and the exhaust isn't real bad, but it does have some. What is weird though is the motor runs perfectly. I would think a rich condition would cause it to load up and stumble. The last time I pulled the plugs to replace them I was amazed at how bad they were and how good the mower ran. When I did the head gaskets a few weeks ago obviously the carb had to come off and I removed the bowl and gave it a good inspection. Besides a little bit of dirt where the butterfly shaft goes into the carb body it looked extremely clean inside. I also blew out all the passages just to because I was there already. I do a lot of carb work in my motorcycle business so I am pretty good in the carb department. The air cleaner is new and I have been blowing it out after each use since I discovered the common dust ingestion issue with these motors. I haven't checked the choke to make sure it is opening all the way and that will definitely get inspected today. Thanks for the response!

 

[Mad Mackie]

A leaking fuel pump diaphragm can also let fuel pass directly into the engine.
Mad Mackie in CT

 

[Mr. Shamrock]

A leaking fuel pump diaphragm can also let fuel pass directly into the engine.
Mad Mackie in CT

It would have to leak through the vacuum line going into the valve cover right? The float needle/seat would stop addittional fuel from entering through the carb (assuming it is working properly). Plus it would cause the oil level to rise. If it was the vacuum line it seems like it would affect just the side with the line ging to it which was the side that I initially suspected an issue with, but the other side had the worst carbon build-up. Unless the fuel entering that side was actually aiding in the carbon cleaning some. I will go out there now and pull the vaccum line off the pump to see if it is wet. Thanks again for the help!
I also checked the choke earlier and it was adjusted properly according to the manual and I can see it opening and closing properly.

 

[Mr. Shamrock]

Well you might be on to something Mad Mackie. I got a few drops of gas out of the vaccum port on the pump when I removed the line. Also there is a buildup of dirt around where the line goes into the valve cover. I just cleaned the valve covers then I had the heads off a few weeks ago. I am going to order a new pump and line and see if that helps. Thanks a million!!!!

 

[Mr. Shamrock]

Alright got it ordered - man of this ends up being the culprit I will definitely be :biggrin:

 

[yanever]

I am watching this closely. I have the same identical problem and am doing about the same things to try to fix. Have been searching the forums for an answer and i see a lot of Briggs engines using a lot of oil in a short time, but I have not seen anybody fix the problem most everybody looks to the valve timing, valves, and they have the carbon build up you mention. They also change the oil, filter, breather with no help. Hope you have the right solution.

 

[Mr. Shamrock]

I hope so too. I received the pump and vacuum line yesterday. Unfortunately they sent the wrong line. Apparantly there are 2 different ones for this motor depending on the date code and of course I got the wrong one. There is a shop not too far that has a few in stock so I am going to pick one up on my way home today. I am sure the grass will need to be cut over the weekend plus my dad's needs to be done (his grows way slower than mine) so it will get a few hours of run time on it. I will keep you posted.

 

[Mr. Shamrock]

I drove over to the shop that claimed to have 9 of the hoses in stock and, guess what, they had ZERO. I am done with that shop. I bought my mower from them and they have pretty much let me down each and every time I have went back for anything. The owner had the nerve to blame the misprint in the computer on his 13 year old son. Anyway, I made some calls and the nearest shop was 30 minutes away so I rode over there and got it. I also met a real nice shop owner who will be getting my business from now on. The pump and new line are installed so it is ready.

 

[4Putt]

Hello Mr Shamrock. We have a 16hp briggs inteck twin on a simplicity. It has about 350-380 hours on it. If I didnt know better I thought I wrote this thread because I have pulled my hair out with oil usage also. I, like you, cant figure out where its going. Motor runs strong as can be and does not smoke. When pulling a big hill under full load I sometimes think I may see a faint hint of blue smoke. So faint, I cant be sure and it may be in my head. Compression was within 2 lbs of each cylinder. In 20 hours this year, it has already gone through 2 additional quarts of oil. Roughly, 3 oz per hour.

It has had briggs 30 weight in it since new with oil changes every 50 hours. I recently tried Rotella T 5w 40. No change. Im about to try Rotella 15w 40 because I have some and expect no change. I have not gone to all the trouble you have. The plugs look terrible after a while and I even wondered how in the world they would fire.

My engine has not had the best of maintenence in all honesty. My plan now is to change the oil every 25 hours give or take and keep a super close eye on the filter and make sure the fins are clean after each use. These engines from my research are notorious for poor filtratation and I suspect this is what happened in our case. My Dad ran it one time so long that it just quit only to find out the filter was clogged. I imagine the damage was done right then and there. I have now taken over since he cant any longer. One other time he said it just quit because the plugs fouled out.

The goal here is just to run it till she blows. I am simply trying to extend what life is left in it. The Simplicity is a super good mower and the engine still runs strong power wise but you have to add oil at each mowing. It typically goes down to the add mark after an hour to an hour and a half of running. I also added some Kreen (additive to clean up sludge) just as a long shot. I normally dont believe in additives but this stuff works good if you have a dirty engine and I figured I didnt have anything to lose.

I dont know what else to do other than to just run it and try to nurse what I can out of it.

 

[Tundras]

I have a 17.5 briggs engine on a snapper rider. I change the oil and filter religiously with quality products. One month ago the engine (suddenly) started burning oil, way more than normal. I started reading the threads and decided to start with the easy stuff. While examining the engine I decided to pull the spark plug. It was not very tight (I.e loose) and when I pulled it, it was filthy. I put in new plug and tightened it to spec. Solved ????

I'll let you know after I mow this weekend.