I have this old B&S mower engine probably late 60s to early 70s vintage. It's around 3 hp or so. Some one gave it to me when I was a teenager. It always had this problem where it would get hot and not want to start. You only have to run it for a few minutes and when you shut it down, it will be hard to restart or won't start at all. I thought it was worn out at the time so I pulled it off the deck and stored it for parts. Later on my buddy was taking a small engine class in HS and I had him rebuild it for me. I never really had a use for it so it sat for a few more years. Next time I tried using it I mowed my front lawn and shut it off, and I could never get to start again. The same problem that it always had. Then it sat for a few more years. Now it's back to aggravate me again. I really want to get it going this time. I've been waiting some 16 years to get my money's worth out of it. It does run fairly good when it is running. I mounted it on an old deck, so I now have a handy test stand for it. I started it a few times in the last day or so, and just let it run. I am thinking it's probably the carb that is needing some thing. Any ideas what I should looking for? Also where is a good setting for the one mixture screw on the carb? The engine numbers are 92502 0780-02 75101009

Thanks Mike

could be a bad coil or something as simple as a bad spark plug. Have you done any troubleshooting?

Jake..

The spark is good, new plug, points,condenser. The compression is good. Tank is clean, fuel is fresh, carb is clean. Next I will try replacing the diaphragm in the carb and see if it makes a difference. I also need to check the choke, and make sure it's adjusted right.

Mike

I think you're going in the right direction. I would still be a little suspect of the coil. If everything else is correct and you replace the diaphram in the carb. there isn't much left except the coil.

Jake

I do have a spare coil from another mower engine. It wouldn't hurt to try it and see what happens.

Mike

Mike, you probably already know this but, be sure to set the air gap at .010"

Jake..

.010 gap, ok I'll check that. I was looking for some paperwork today and ran across an old manual for the engine. I forgot I even had it, never did find what I was looking for. Any way the booklet covers the carb adjustment. It even says to lean out the mixture, if engine is hard to start when hot. I'll try that adjustment and check that air gap tomorrow morning. I'll post the results of what I find.

Thanks Mike

Update

Set carb per manual, checked air gap it was at .010. Ran engine for a few min, shut it off and it wouldn't restart. Swaped coils and still same condition. As soon as it warms up, it wont restart untill it cools down.
Should I replace the condencer next? Any other ideas guys.

Thanks Mike

junky

are you trying to keep this engine in an antique form?....if not i wouls save my self a lot of headache and dump the old condenser and point system and get a electronic ignition system for it...lots more reliable....

http://shop.briggsandstratton.com/BShopProductPage.asp?CategoryID=206&PARENTID=0&MECID=100&ProductID=56B2BB0E-283C-11D4-8886-00B0D0203414

cajun

Mike;

Try the condenser next. If that doesn't remedy the problem, I would start looking at the rebuild work that was performed on the engine. Recheck the compression first. If it is at all weak it could be a valve not seating properly after warming up. Could also be a head gasket problem. I would change the spark plug also. Even a new plug can go bad. It's easy and quick. You said the fuel is clean. Does the fuel line have a filter on it? Is the gas cap vented to the atmosphere? This will cause an engine to stall after running only a short time.
Try these suggestions and let me know how you make out.

Jake T.

Hi Jake

I will do the compression check just for kicks. My buddy Dan was a good mechanic, his brother on the other hand was a shady one. I would think Dan would do good work, but I'll check that compression. I'll swap that condenser and replace the carb diaphragm. Will post the results. I never really thought about converting to solid state ignition. It would probably be the way to go. I really don't have any extra cash right now, so that is out of the question. I will just have to use the extra parts I have around for now.

Thanks

Mike