I managed to get the 1250 completely reassembled yesterday and spent a bit of time wirebrushing the adjustable links in the deck.
The good news is that it now holds oil and runs a bit better/smoother than it did previously. On the subject of vibration, its pretty similar to my brother's 147 that I spent quite a bit of time working on everything BUT the engine previously in addition to using. Both tractors vibrate a good bit while at low RPMs, but smooth out nicely at high RPMs, so I believe the new ISO mounts are working pretty nicely. Previously this tractor shook like crazy regardless of engine speed due to flattened rear mounts. For the record, I used the 2-3 threads above the nut method for ISO mount installation.
My question now is how to tune the engine. Despite today's rain, I took it for a test ride to see how it behaved and it still is acting similar to when I bought it. It doesnt idle and seems to have very little power. Climbing a very slight hill (more of a slight rise) in the lawn at low (crawl) tractor speed and high ~3600 engine speed with the mower going requires stopping several times as the engine is "lugging" down close to stalling. It also will occasionally backfire through the carb upon shutdown and/or while cranking.
I have cleaned the carb thoroughly and installed the standard Kohler carb kit for gaskets/needles etc, but something still isnt right. The engine starts right up on 6-8 revolutions, but requires full choke everytime to begin firing, then once firing requires choke off and mid-full throttle to actually run - idle needle too lean maybe? Once running, it doesnt really want to idle. It will run somewhat consistently in the mid RPM range, but doesnt really run smoothly until up around 3600. Ive tried adjusting the needle/jet from the factory settings (2.5 turns out) both directions per the service manual, using the sound of the engine speed increasing/decreasing with a final setting halfway between, and that seems to work for the main jet for the high RPM range, but the idle needle doesnt seem to affect the engine in the least regardless of the direction turned even at full in, which makes me suspect an issue there. Any ideas?
One other thing Ive tried is adjusting the points gap. When the engine was out I found the original points in a glob of greasy crap in the frame so I pulled the cover and found the gap at something over .020. I reset them to .017 and it ran a bit better, but I suspect this also may be a bit off. I tried Matt's static timing method, but unfortunately I cannot see a timing mark close to the opening point. I see a vague one ~1/2 revolution out, but could be seeing things. Is there supposed to be a stamped T and S, or are there simply two dash - marks on the smooth portion of flywheel to the left of the gear teeth? I suspect I need to get in there with Q tips or brake cleaner to clean some rust/crap off the marks.
As always, thanks for all of the assistance. I am hopeful that with your assistance I can get this similar to my brother's 147 - a good solid tractor with plenty of power that runs smoothly, quietly, and is an absolute joy to mow with.
Carl
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