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Broken piston rod questions.....

4793 Views 9 Replies 7 Participants Last post by  RoyM
I could use some help on this. As the title says, my 21hp Briggs tossed a rod and I'm trying to decide if it's worth fixing. It's one of those ohv Intek motors that I have read on here just aren't very good. The crank is gouged up pretty good where the rod used to connect. I don't want to buy a new crank. The cost is almost half a new crate motor. Is this something I could bring to a machine shop and have honed? If I do have it smoothed out how does this affect the rod where it attaches to the crank. I don't see any bearing in the part list. Is the connecting end of the rod adjustable? The piston and cylinder walls look fine. Is there anything else I should be looking for or replacing? In the last month the camshaft broke and now the piston rod. Are these common problems for these engines? I am not running it out of oil, so I am wondering if it's something else....head gasket? No loss of power.....but I'm losing parts at a pretty good clip......any advice?
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It is junk please please send it to me!

Assuming it is a single cylinder Briggs Intek and only the rod is damaged: The problem with these engines is that the head gasket fails. The $10 head gasket is not all that difficult to change but generally people keep using them and bust the rod. That makes it a bad engine.

The big end of the rod seized to the crank and has left aluminum deposits on the crank. These can be removed with muriatic acid. Be sure to get all the aluminum off or it will seize again.

Get a new rod. Tear down and clean the engine top to bottom, and put it all back together. If the cylinder wall is in good shape there is no need to hone because the rings are already seated.

While you have the engine apart mark the flywheel with the piston 1/4" past TDC. This will make setting the valves easier.

I have seen a new procedure for torquing the head that is supposed to fix the problem with the gasket. Not sure where, maybe here. I have asked Briggs for a link to their service bulletin as my info is 2nd hand.

New head torque, 250 inch lbs in 3 steps.
Pattern, original order is black, new order is red.


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If this is like the other craftsman's I have seen there are two sets of engine mounting holes and it should accept any vertical engine of about 11 to 25 HP.

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