newbie here. first time. durham NC. some backstory: my sons run a yard business. they have two john deere 36" walk behinds from the 80s, both with FB460v engines. they've probably averaged 10-15 yards a week, 8 months a year, for 10 years ... definitely more than 3000 yards. Those kawasaki engines have put one kid through college and we are hoping they will put another one through, too. Over 10 years we've played the mechanic role quite a bit, but those things have been so dang reliable we haven't had to do much except spindle bearings. we religiously change the oil, lube, belts, and put in tune up kits. we have two mowers so we understand the need for a backup. now to the story.
mower A. the first mower was virtually the only one used for the first 8 years. one day a piston came out of the very back of the engine. there's a diagonal plate on the rear side of the engine held on by four nuts. it has a circular indentation in it. Behind that plate there is a piston. I know that because for some unknown reason the nuts worked off and the piston gently slid out, out of the blue. what the heck? The piston looked fine. I order an o ring for the piston, put it back in there and it fired up. But the engine is way louder than it used to be, unsettling for sure. I have no idea what else might have happened in that engine. I never diagnosed it further. now we live on the edge with one mower.
mower B. now mower B is burning some oil, and it, too, recently sounds louder than it should. first we were hoping it was a bad muffler, but we put a good muffler on it and that didn't help.
so now we are worried we might be left high and dry with two bum engines. with this many customers we need a big mower. dang. we really need two. i might be able to pick up a used FB460v, but it's a long haul to go get it.
So here is my request for wisdom:
From reading the forum and the manual, it seems like carbon build up is a big deal on these engines. the manufacturer suggests cleaning carbon from piston/valves at 300 hours. Mower A has gone 2500 hours (since we've had it!) without us doing that. Mower B has gone 1000 hours or more. So should I try that service? Can i get the head gasket? I haven't checked compression. Would that help? Or given the parts cost and availability, should I just try to find another engine?
Basically I need to figure out a) how "sick" are these engines? how can i diagnose what's really going on? and b) given what everyone knows about these engines, what is a wise next step? They both run, but we are lacking confidence in them. c) should I start trying to diagnose/fix mower A (since mower B is cutting yards now)? Or is that engine shot? Or should I try to do something to Mower B before it gets worse?
Please advise. I have the manual. we are pretty mechanically inclined (never done a whole engine but not intimidated to try). we are very teachable.
thanks in advance for your wisdom. we appreciate it. rick and mark
tobers, Seems like you have had more than reasonable life from these engines? Read the newest thread here and the advice about buying a new engine rather than rebuilding. It is easy to make mistakes (machine shop) and parts are expensive. Good luck
