View Full Version : Mower help

09-16-2009, 01:19 AM
Ok so I am not the best at engine repair so I hope someone here can advise me. My old mower finally caved in while on a job not long ago. I replaced it and didn't skip a beet. Once I got home and got everything cleaned off I replaced the primer bulb which looked melted inside, replaced a badly fouled plug and completely cleaned the carb and tank. I reassembled it and took it out back and it ran great I had a job to do today where the client typically lets the grass get 2-3 feet tall before calling. I figured rather than abuse my new mower I would use the old one. Well after 30 minutes of use the plug fouled again and I was forced to use the new one. Did I miss anything or is my old mower simply burned out? I am thinking the rings are dead and allowing oil into the combustion chamber. Any thoughts?

09-16-2009, 04:53 AM
I assume this is a four stroke? If so probably time for a valve and or ring job, simple to do and doesn't cost that much.

09-16-2009, 09:13 AM
Do you think its worth the time and money? Especially since I already purchased a shinny new one? Maybe this one would be good just for those properties that let the lawn get out of hand. hmmm I wander where I would get the parts even. Maybe Lowes.

09-16-2009, 09:14 AM
I assume this is a four stroke? If so probably time for a valve and or ring job, simple to do and doesn't cost that much.

Oh yes I almost forgot it is a 4 stroke. 3.5hp B&S.

09-16-2009, 11:35 AM
Oh yes I almost forgot it is a 4 stroke. 3.5hp B&S.

Worth the time and money?? Probably not, could be a something to do over the winter and a beater mower is always good for certain lawns, then again you can probably get a good working 3.5 Briggs for $50.00, I see them in the buy and sell here all the time.

09-16-2009, 11:53 AM
Maybe best to just toss it in the bone yard on the back 40 next to my chipper and use it for parts. hmmm.

09-16-2009, 12:35 PM
Did it look like it was blowing smoke out the exhaust?

I did a quick search for

3.5hp B&S rebuild kit

and found this


09-16-2009, 12:43 PM
It blows smoke when it first starts but stops quickly. It has done this for years though.

09-17-2009, 06:54 PM
Does it lose oil? Another words, after you use it awhile, do you need to add oil? Also, out of curiosity, has the oil been changed in the motor regularly?

There are other possible problems. Keep in mind that fuel/carb issues may very well be causing your problems. An incorrectly adjusted carburetor can permit too much gas to enter the combustion chamber and in turn foul your spark plug. A dirty air filter can do the same.

As far as the oil issue, it is possible that the rings have too much wear and have just started permitting the oil to come past the rings. Now keep in mind also that there are a number of other reasons for the oil to be able to get by the rings without the rings just having too much wear.

One of these, though not very common among small engines, is the possibility that at least one ring (typically the oil ring) is broken. More common, yet very uncommon, is the possibility that the rings have lost their compression. This would normally be a result of the engine overheating, though it could be from a variety of reasons, including poor workmanship. One of the primary reasons for a small gas engine to over heat is debris in the cooling fins.

There are so many reasons for your engine to do what yours is doing that do not necessarily include the need for your engine to be rebuilt. And if it does need rebuilt, let me tell you, it is a waste of your money. Now on the other hand, if you want to do the work yourself just for the experience, that is a whole different conversation. Now let me tell you, the parts and tools needed to do a proper overhaul on your engine is going to be cost prohibitive. Like someone else mentioned, you should be able to pick up a used mower for anywhere from $30-$60. If you asked me to rebuild that engine it would cost you at least that much. Or MORE....

Moral of the story is, buy another used one if you want a rough one for rough jobs.

Hope this helps,

09-18-2009, 08:47 AM
I completely dissembled and cleaned the carb and gas tank, thats what I thought it was. When I did this I took all the tin off the motor and cleaned everything. The kill switch was pretty gunked up but there was little to no dirt or debris around the cooling fins. I did over heat the motor pretty bad earlier this year. I was mowing my 1/2 acre of 2 foot tall weeds and noticed it start running funny and the head started to smoke. I let it cool for an hour then got back at it but soon it died. I replaced the plug and filter and it ran like new again. This mower is about 6 years old and stupid me changed the oil only one time earlier this year. I have no doubt the motor is finally just given up. After all its been through 6 years of abuse and only one oil change. AS far as using oil I have never had to add oil to it. Even 5 years of use on the factory oil and it was still on the full mark. I have only one client that really lets there lawn get out of hand. This last week when I did his yard I told him we will eather have to get him on a bi weekly schedule rather than a monthly schedule or I would have to start using my big WW which essentially is going to cost 3 times as much and take twice as long. I explained to him that this way of doing things is very very hard on my equipment. I have yet to get an answer from him but hopefully he will get with the program.