# 1975 Sears SS16 - bogging down under load



## mdroll7780 (Apr 26, 2017)

Hey everyone. Just joined and first post, so pardon any etiquette mistakes. I recently purchased a 1975 Sears SS16 that was mostly restored. Its in great shape. I finally got the mower deck mounted and adjusted (after some reversing of mounting brackets that were installed incorrectly! ha!) and am having some issues with the engine bogging down shortly after I engage the clutch to mower deck. It hasn't actually quit, but stumbles and coughs a bit like its going to. I believe I have everything installed correctly and all pullies seem to turn freely as they should. There is a deck snubber that releases as the clutch lever is engaged and that seems to be working correctly. Im wondering if maybe an ignition issue or fuel flow that works ok under no load, but cannot satisfy the demand under heavier load?? It has the Onan engine. A couple other smaller issues Im still working on, but in case anyone has dealt with these before let me know:

1) The mower clutch does not stay engaged. When I let it go it snaps back to the off position. Maybe just adjustment but I don't quite see how adjusting it would fix issue.

2) The oil distick cap rattles like a sewing machine. I believe it is suuposed to "snap" over the filler tube and wondering if the gasket is worn down ar dried up too much? I can probably find some type of O-ring to slide over and wedge into the filler tube but woder if any other proven solution.

Thanks everyone! Looks like a great forum!


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## jhngardner367 (Apr 5, 2011)

Welcome to the forum !
It sounds as if either the points are not set correctly,or the carb may be out of adjustment.
The Onan engines are good,strong engines,when tuned properly.
That is a great looking machine,so ,I'm thinking it's a matter of tuning.
As for the pto engagement,if I remember,correctly, it should be adjustable.
It needs to lock down,so try adjusting the lever travel.
The oil dipstick should have an "o" ring that keeps it in place.


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## mdroll7780 (Apr 26, 2017)

Thanks for the input. Looks like a rainy weekend so plan to pull it in the garage and work on those things. I'll post updates, or more questions! Ha!


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## Bill Kapaun (May 8, 2007)

Make sure both cylinders are firing equally.


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## mdroll7780 (Apr 26, 2017)

Well, one thing at a time. With regards to the PTO lever not staying engaged, finally discovered the mower deck mounting brackets were installed wrong, which shifted over the connecting rod that pushed out the mule drive just enough to push against part of the frame when engaged, and would try to "spring" it back to off position. There are grooves in the front mounting bracket that accepts the frame, and should be mounted on the inside. A picture is attached for fun showing the incorrect mounting, as this was not at all what I thought the problem would be. One item down, a couple more to go!


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## mdroll7780 (Apr 26, 2017)

Thanks for the input. Got the old girl running well. The carb was out of adjustment, but didn't seem to bother it until it was under load. It appears it was set too rich. I went through the carb setup and tuning again from start and runs well now. PTO stays engaged and mows quite well. Time to get some work done!


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## jhngardner367 (Apr 5, 2011)

You need to put that pretty little tractor in the registry ,so we can nominate it for "Tractor of the Month" !


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