Need advice for two bad lawn tractors...

12 years ago

lawn tractor 1: Got used, 18.5hp craftsman w/ 42in deck. Ran fine, hard starting. Started to shutdown after 15-20 mins (second season). Took apart carb and checked/cleaned - didn't change anything - hard start and 15-20 min runtime. Parked behind shed. Got another used lawntractor....

lawn tractor 2: Got used (free) 16hp craftsman w 42in deck, plow, bagger, hydrostatic trans. Ran for 2 seasons. Now on season 3 - two weeks ago was mowing and hit a rock on edge of property - continued running, but something didn't feel right. Not running too rough but didn't feel right, ran for 30 mins more. Once I parked it and tried restarting it, it would turn over but no ignition! Never had any problems with starting other then the face that it needs a new flywheel gear.

Ordered parts for mower - figuring it's either a failed coil or a sheered flywheel key. Ordered coil, flywheel puller, flywheel key, head gasket kit (light oil burning), oil tube seal, starter gear set w/new alum flywheel gear.

Today installed new flywheel gear, FYI those rivets holding the original on are the worst to get out! Installed new coil, and reused the same key for testing - it's not sheered. Still not starting, but it's kicks the wrong way after a few revs and stops.

So now what? I understand timing would be expected but the original key was in perfect shape.

And now after reading allot more today I understand that the original mower (still behind shed), could probably be fixed with a valve adjustment and maybe some head carbon cleanup. Thinking of swapping out motors if I have to but wanted any advice on my current no start issue. Any suggestions?

Motor: B&S 28N707-0173 Slightly burns oil (going to redo head gasket)

Has new flywheel gear (original was in bad shape)

Has new coil

Has Spark

Flywheel key checked

Thanks for any reply's

Curtis Reno

PS: Am a novice, but don't mind learning.

Sort by:Oldest

Comments (4)

walt2002
12 years ago
You don't say what the model number of the 18.5 hp engine is. It is common for valve adjustment to cause problems with B&S OHV engines turning over. I have detailed instructions for setting the valves plus other helpful hints IF that is what you have and you want them. Address below, put in proper format and remind me.

As for 28 series engine kicking back, that sounds to me like you did not properly torque the flywheel nut/bolt and partially sheared the flywheel key. Just because the flywheel key was OK when you checked it doesn't mean it is now. Might check for water/crape in carb float bowl fist though.

Walt Conner
wconner5 at frontier dot com
creno
Original Author
12 years ago
Thanks for the reply, The kickback problem was my stupidity! Didn't tighten it down enough just like you said. Sheered the key in half. Thank god I reused the old one for testing - had the new one just waiting to be inserted, and torqued it down good. Lawn tractor runs better then before. Also adjusted the timing when it was apart earlier. Able to cut my lawn finally!!! And with the new flywheel gear no more aligning the flywheel to catch a few good teeth to start :)
Also I haven't pulled apart the head, I installed a new oil dipstick seal - will see if it helps the old one was shot. Wasn't burning too much oil just little over time. I'm hoping it was just too much air getting past the old seal.

Within a couple of weeks I'm going to revisit the one behind the shed. I need a new starter for it but I think I can resurrect it now.

Thanks for the info Walt, may email you when I tackle the other one.

Curtis Reno
Related Professionals
Allentown Landscape Architects & Landscape Designers · Manhattan Beach Landscape Architects & Landscape Designers · Wixom Landscape Architects & Landscape Designers · Finneytown Landscape Architects & Landscape Designers · Fridley Landscape Contractors · Lemay Landscape Contractors · Monterey Landscape Contractors · Point Pleasant Landscape Contractors · Ringwood Landscape Contractors · Roswell Landscape Contractors · Streamwood Landscape Contractors · Thornton Landscape Contractors · Vancouver Landscape Contractors · Plainfield Carpenters · Sugar Land Carpenters
walt2002
12 years ago
"- had the new one just waiting to be inserted, and torqued it down good. "

I still don't know what model number that engine is and they do have a specific torque value for the flywheel nut. 100 ft. lbs. for 31 series engine, 65 ft. lbs for 28 series and 150 ft. lbs for 42 series.

"Also adjusted the timing when it was apart earlier."

And just how did you do that? There is no timing adjustment. I suggest you get a Service Manual.

Walt Conner
creno
Original Author
12 years ago
oops, I ment adjusted the valves, Not timing. Sorry been reading too much lately on engines. I'm a computer tech not a mechanic, but i'm learning.