Small engine repair or trash?

I don't know whether it needs to come off of the frame. I suspect that if the big end of the connecting rod is bad then the crank probably is too. But by all means you should look inside the motor. At the very least you can show your son exactly what happened and why it is not a good idea to run the motor too fast for too long. I don't think anyone can tell you whether it is worth fixing until you tell us what has happened to the motor. Eric

Most of those Briggs engines need to be kept at 3600 RPM or below. If you need more speed you do it with gearing.

That being said, you probably need to pull the motor off the rig to work on it anyway, so buy a manual, pull it, and take it apart. Then add up the parts and see what they cost. At that point it's a matter of how much you value your time vs how much teaching your son how to tear down and rebuild an engine is worth.

riding lawn mover that he wanted to get rid of, mower deck rotten and engin e smoke. I gave him $50 for it and gave it to my son (age 12) to play with . We had a nice time, cleaned the carb, and got it running nicely. And th en we removed the governor and wired in directly to the throttle. (He made a throttle pedal from a bicycle hand brake.) I warned him about keeping t o engine revs up for extended periods of time.. but not enough I guess. An yway he had a great time bombing around the place on it. Then last week he had it stopped. It had lost power and was making clanking noises. (Motor is 17 HP Briggs and Stratton twin, two pistons) He pulled of the head on the noisy side and the piston has ~1/4-1/2 inch of "play". I assume he tra shed one (or both) of the bearings in the piston rod. I'm inclined to work with him and take it apart. But I'm wondering if it's a lost cause? Any thoughts, ideas or

f the frame to repair it?

Thanks Eric, Maybe this weekend. (if it's rainy)

George H.

The engine has to come off. Good project for father and son - even if you just take it apart to see what happened and find it isn't worth fixing. He'll at least get an understanding of what is inside and how it works - and what happens when you over-rev an engine (particularly a smoker - if you don't keep the oil replentished!!)

In MANY cases the aluminum just welds to the crank and doesn't do any damage to the steel crank that a soaking with lye won't remove.

Check what the go-cart guys are doing with Briggs engines. For some of those guys 3600 is "just above idle" - but modifications ARE required .

17 HP Briggs and Stratton twin, two pistons) He pulled of the head on the noisy side and the piston has ~1/4-1/2 inch of "play". I assume he trashed one (or both) of the bearings in the piston rod. I'm inclined to work with him and take it apart. But I'm wondering if it's a lost cause? Any thoughts, ideas or opinions are welcome. Oh, I also wonder if I need to take the engine off the frame to repair it?

Thanks

George H. ====================== Is it the opposed or the vee twin?

Write down the whole model and serial number and buy a manual that covers it, like the Haynes. They are pretty simple but some things aren't obvious, and you may need a few special tools.

I disassemble engines on a shallow baking tray that catches the remaining oil.

-jsw

I was just thinking about my first experience with taking apart a Briggs motor. When I was 14 or 15 I bought an old horizontal shaft lawnmower engine to see how they worked. I took the thing apart and put it back together without any sort of guidance. Then I managed to get it to run on all sorts of fuels. Stuff like Cox glow fuel, paint thinner, charcoal lighter, propane, acetylene, and so on. I had a great time playing with that engine and learned a lot. This could be a real fun time for your son if he is interested in engines. He could see how they work and see what happens when you change stuff. Eric

I think that it will be instructive to attempt the repair, even if nothing can be done about it. Let him see what happens when you push it too hard -- that will teach him a lot better than just telling him.

I suspect that the bearing in the crankshaft is a lost cause by now. :-) But being able to point to the difference between a trashed bearing and a (hopefully still) good one may be instructive, too.

As for advice as to how to access it -- no experience with that so I can't help there.

Good Luck, DoN.

B&S offers at least some of their manuals free online. Got one for my early '70s 5 hp horizontal shaft that way, it seems to be a complete version.

HTH,

bob prohaska

You can download manuals etc. for most B&S engines on line as I have done for every dumpster dive lawn mower I have come across for the pas few years.

The only problem with factory manuals is that they assume you have some experience or source of advice and all their special tools.

Aftermarket manuals may tell you how to make or substitute for special tools and provide more guidance for novices working alone. I have the full factory repair manual sets for my vehicles and still refer to the Haynes books sometimes, because it tells when to seek professional help instead of assuming you have to be it.

-jsw

Well, yeah. Mud motor guys are over revving them as well, but if kept within their designed range they will last a very very long time.

.

Hey George, this has already been said, but allow me to say it my way:

In a monetary value for money & time spent trade, it's probably a lost cause.

However, when you factor in the value of the learning opportunity, it's got to at least be worth it to tear it down so he can see how an engine is put together, and how much damage you can do by abusing it.

Then, if you both want to fix it -- for the learning experience -- order parts and go to it. If not, then look for another junk lawn mower on Craig's list.

There were kits to make self powered 2 cyl compressors from a VW bug engine, and 4 cyl self powered industrial compressors from Flathead Ford V8s, among others. There were also commercially made self powered compressors - Atlas Copco I think was one -

Perhaps they've improved, my memories of Haynes and Clymer manuals put them far inferior to factory documents for simply laying out what needed to be done. That was 30+ years ago.

bob

Right. My 5 hp B&S was purchased new in an MTD brush chipper. A governor kept revs in check, oil was kept topped up, and that Piece-Of-Shit suffered valve/guide failure at around 20 hours!

5 hp really isn't enough to chip brush. Briggs & Stratton is shit.

As I wrote I have both, including for small engines. I find the aftermarket manuals helpful the first time I do something since the factory ones were written for pros with tools and experience. Also they are thin enough to carry in the vehicle. The factory manuals for my truck form an 18 Lb stack 7.5" high.

-jsw

Like Bob, I've also heard that B&S aren't as good as they once were. "Once" must be greater than 15 years ago. Mine was bought new 15 years ago. I won't be buying Briggs & Stratton again.