This procedure will tell you if there is any wear or play in the Wrist Pin, Wrist Pin Bearing, or Connecting Rod to Crankshaft area.
Remove the spark plugs. Insert a screwdriver, dowel, punch, or some object of your choice through the s/plug hole and into the cylinder/piston area. Hold the tool lightly against the top of the piston. Turn the flywheel by hand, bringing the piston up to top dead center, then continue turning the flywheel to pull the piston down about a inch..... all the while holding the tool lightly against the piston top.
Now, at the point whereas the piston has been dropped down about a inch, grab the flywheel and hold it firmly. Now, push that tool solidly and firmly against the piston top.
If the piston moves without moving the flywheel, there is a problem (wear, play, clearance, etc) somewhere with the items mention in the first sentence. Be sure to check all of the pistons/cylinders.
Well, husband took motor completely apart. The camshaft bearing was thrown and a bolt was broken off. Upon further teardown, found a hole created by all that in the casing! Now what? Can I buy the casing from a junkyard? Someone suggested welding the hole but that doesn't seem like a viable solution to me. I'll take any suggestions as I'm thoroughly upset.
I strongly suspect that the cam you mention is actually the crankshaft, and the broken bolt is from the retaining portion of the connecting rod. As such, again I strongly suspect that the crankshaft and that connecting rod (at a minimum) will require replacing. This, coupled with the damaged crankcase (hole in the block) really spells out a non rebuildable powerhead.
Yes the crankcase could have a hole in that aluminum crankcase heli arced (aluminum weld) BUT there may be other unseen damage to the crankcase that will result in wasted money and double work.
I wondering, instead of tearing the engine down which would eliminate any implied warranty, why you would not contact the seller about that knocking problem....... that is if the knocking existed right at the start. At any rate, I understand your frustration and can only suggest that you are able to locate a good used powerhead to replace your damaged one.
You're right, it is the crankshaft, I misunderstood him. Considering it's a 1992 motor, there is no warranty. We bought the boat from an individual and did contact him but he said he never had any probs with the motor. I tend to believe since he's a pastor, but you never know. We had the welding done to the hole & a small crack that was discovered & replaced the bearings.
New question: The knocking is gone & motor runs, but it sputters. Think the crankshaft may have gotten warped. Wondering if we have the crankshaft turned if we can use the same pistons & bearings?
You can't have the crankshaft "turned" ... bearings (main and rod) are only made in one size. It may be possible (but probably not cost effective, to have it remanufactured (weld material added, then turned down to original specs). A better path would be to find a good, serviceable, used crankshaft.
Just to make that a little clearer.If the carb on a 2 stroke runs a little lean
(Not quite enough gas) The crank etc may not get enough lube.
If the motor seemed to stumble or bog on acceleration and maybe not top out strongly could be running lean.Sometimes if a motor is running lean a little choke will help it respond.An indication you need to solve the problem.
Usually a carb rebuild.
New boat owner - engine knocking
Linear Mode
