4 Stroke Lawnmower Engines

Bamby

New member
I now own two toro personal pace lawnmowers that the decks and wheels are outstanding but the engines in both suffered a hard strike stall and are now somewhat screwed up. The key was replaced on both of them but they still won't run as they did or should.

I now suspect that the cranks are now twisted on them and they are now running out of time without making any real power. These are briggs & stratten engines which are common as dirt but are they readily exchangeable? Anyone Know?

If so there is a huge horde of cheap used motors out there that could possibly be exchanged. Or even possibly a new in the box engine from maybe Northern Tool.
 

mla2ofus

Well-known member
GOLD Site Supporter
More likely the lower half of the crank is bent. I've never heard of one twisting. I used a method I read about to straighten a friend's bent crank. Got it to less than .030" with my dial indicator, filled it with gas and oil, put visegrips on the run/kill handle and let it run for 45 min in the yard because I'd heard of cranks breaking after straightening. Friend has used it for 3 years with no problem.
Mike
 

Bamby

New member
Yea they will now technology run but they're running like lawn boys run. Run fine until you push them up against a tuff of grass and the stall, always hated lawn boys for that whereas a four stroke warn you enough to ease up on it a bit and keep chewing up grass. But now I find myself high and dry with damn doggy lawn boys to deal with and I'd like my briggs back.
 

mla2ofus

Well-known member
GOLD Site Supporter
If you really like your mower deck you can do as I did for my old Wizard with cast aluminum deck. The old briggs finally got too tired and I ordered a briggs replacement from small engine warehouse. Yes, It cost a little more than a new 20" mower but I felt the old deck was worth putting $$ into. I have no idea how old it is. How long has Western Auto been gone??
If you're interested get all the #s off the briggs and call them.
Mike
 

FrancSevin

Proudly Deplorable
GOLD Site Supporter
I have had very good luck with (Please don't laugh) Harbor Freight engines.

The B&S engine on my MDT Cultivator went after only 6 years of service. I put a $99.00 HB on it in 2010. Still runs today.
However, If you want a reliable engine that will run damn near forever, HONDA.
 

TiredRetired

Mr Lovable
SUPER Site Supporter
Your Lawnboys are not up to power because of the EPA mandated jets in the carb. The orifice is undersized thanks to government meddling in our lives. This was not good enough for the EPA as two stroke engines are now outlawed thanks to more intervention in our lives.

Two stroke engines have more power than equal size four stroke engines if allowed to run without that lawnmower version of the NASCAR restrictor plate. I have made this modification on my 2003 Lawnboy and I will put it up against anything out there. Of course it uses more gas after the mod but I could not give a shit less.

As far as drilling the jets, a #77 drill (.018") is used for the pilot jet, and a #67 drill (.032") is used for the main jet.
 
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