[Joe Baring]

I have a Briggs and Stratton 32000 engine. It has been recently rebuilt. The connecting rod is .10 under and the crank was machined to match it. The Machine shop used my .10 under rod to machine the crank. Before I started it I checked the oil and it was full SAE30. Anyway I started it up and ran it for about 20 minutes and it started to surge really bad like the carb was dirty or it was out of gas. I shut it off and filled it up with gas and started it back up it ran fine for about 30 seconds then it started to surge again. This time I started to hear a slight knock so I opened the hood and raised and lowered the rpms to see if the knock was still there. I idled it back down and then it stopped abruptly. The engine was locked up. I pulled it apart and found this. (see pictures) How could this have happened? The oil was fresh and full before and after it locked up. The connecting rod is brand new and the crank was machined to match. I can't install the rod the wrong way because if you do it will hit the camshaft. Also the Briggs and Stratton Manual shows what way to put it in. The piston and rings are also fresh and still in decent shape. What could have caused this to happen I do not think it overheated because all the shields were in place and it ran great. Any help would be appreciated! Thank you all very much!

 

[Joe Baring]

The strange thing is that the oil slinger was installed correctly. When last rebuilding the engine the rod would only go in one way with the oil hole facing away from the crankshaft. If I put it in with the oil hole facing the camshaft then the rod hits the camshaft. Also the Briggs and Stratton manual showed that the oil hole goes away from the camshaft and if installed incorrectly the rod will hit the camshaft. Am I missing something here? Thanks for the advice with the crank. I will definitely give it a try although the rod seems to be badly damaged is that still able to be cleaned up? Thanks for your help!

 

[Joe Baring]

In the past 50 years I've seen ground cranks too big a few times. Mic the crank yourself. I always use plasti-gauge to check the clearance. I assemble rods with STP oil treatment(still have some from a case I bought over 40 years ago). I prefer my clearance right in the middle of the clearance spec. I would not reuse the rod. Good Luck, Rick

Thanks I was starting to think that myself I will check it with plastigauge. Thanks!

 

[Joe Baring]

Well Thats a problem. I just tried to see if it would fit in the engine the correct way and the rod hits the crankshaft every so slightly. Just to clarify the cam shaft side of the engine is also the carburetor side correct? Even the old rod that I took out first when the engine was running was put in backward it seems. Although It ran for many years before the rebuild with the rod in backwards. We even put that connecting rod in the correct way and it still hits the camshaft. I was looking at the manual and I found these 3 pictures. One of these you already found. I looks like picture one says the oil whole goes away from the camshaft because the assembly marks are towards the camshaft. Picture 2 looks like the picture you sent. The assembly holes point away form the camshaft so the oil whole goes toward the camshaft. Picture 3 looks like the side that says "flat" (assuming that is where the oil whole is) points toward the camshaft side meaning that the oil whole is facing the camshaft. I am thoroughly confused what do you think?

 

[Joe Baring]

I got it from a web sight called isavetractors. Although they just took it down I contacted the guy to see if he might have an extra one in his warehouse, but he has not responded yet. I might have to get a .20 under rod. What does the machine shop have to machine the crank to accept a .20 rod. I want to make sure they get the correct clearance this time. Do you know the crank specification for a .20 under rod? I can't find it in my manual.

 

[Joe Baring]

Thank you so very much I will buy the aftermarket rod and now that I have the right crank diameter I can give the number to the machine shop to make sure they have the right clearance. Although After they machine the crank we will check the clearance with plastigauge. Thank you again for your huge help! I would have not figured this out without you!

 

[Joe Baring]

No it wouldn't the machine shop only charged me $60 to get the crank machined. Also I would like to keep this engine as original as possible. Thanks for finding it though! If for some reason This does not work I will get this crankshaft and put a std rod in. I appreciate your help!