OutdoorKing Repair Forum Forums Restoring, Customising and Modifying Tech Talk Scott Bonnar 45 Mower: help with engine service

The missing engine identification numbers are stamped into the tinware in a small font before painting, so you have to look carefully, with oblique light, to see them in many cases. I suspect that the reason your engine has no stickers is that it has been repainted, and the extra paint has completely filled the stamped number-impressions on the right side of the cowl, near the top. One step you might take is to remove the cowl (it is held on by three small hex-head screws) and examine it carefully all over, including on the inside looking for pressure marks from when it was stamped with the long series of numbers.

If you post a picture of the carburetor (under the air filter, above the fuel tank) I'll try to identify what kind it is. As I said before, it sounds rather like it has water in its fuel or crankcase. Have you checked those points?

We can go through a standard first-principles diagnostic procedure if necessary, but that won't help you in future because you still won't have a manual unless you identify the model and type. Also, you are likely to have to disturb things that are better undisturbed.

As a first step, we will need to check spark and compression. That means remove the spark plug, clamp its metal body to an unpainted part of the cyulinder head, attach the plug lead, put the speed control in the start position, pull the starter cord, and watch the gap between the electrodes. You should see a steady series of blue sparks. Next, check the compression. Reinstall the spark plug but don't connect it, put the speed control in the stop position, and turn the clutch in the drive shaft backwards until you reach compression. (Note, turn it backwards, not forwards). When you reach compression, rotate the clutch backwards with a quick flip so it hits compression and bounces off. Observe how vigorously it bounces back. Pull the starter (plug still disconnected) and see how the compression feels. Let us know the outcome from those tests.

Edited a couple of weeks later:
jackg, I wonder if your air cowl was replaced with a new one, somewhere along the line? That would explain the lack of both model/type/code numbers, and B&S stickers.

Chances are your engine is just about identical to the one discussed in later posts in this thread: a late-manufacture 80202. If so the owner manual and illustrated parts list I have shown for that mower will apply similarly to yours. This means that if you come back to this thread and post more about your smoke problem, we will have a proper background to discuss it.