Blown motor

[ringo]

I have a 93 evinrude 200 xp(can get serial number if needed) that I blew over a year ago and was rebuilt by a local marine tech. Ran fine up to three weeks ago when it blew again. A mechanic friend who does some work on outbards said he would rebuild it for me. When tearing down, a nut that holds carb on had backed off, he believed it was sucking air and leaned out the #1(?) cylinder. It had one cylinder down(the top cylinder on left side looking from rear). The block was sent off and bored, and the piston, rings and bearing was replaced on the one cylinder. The motor started fine and while test driving after thirty minutes the same cylinder blew again. Double oil was not used since only one set of rings was being broke in. Before I move forward I would appreciate any help on mistakes that we made or things to check should we foolishly try it again.

Thanks

[OkieBoatMech]

When rebuilding an Evinrude/Johnson ALWAYS replace the VRO assembly, just to cover your tail. We NEVER bore/hone only 1 cylinder at our shop. I hear of it all the time, but its not a good practice. I understand the cost factor too. If we have an engine tore down for machine work, we go ahead and bore/hone all the cylinders and replace the pistons/rings. AND it doesn't matter how many cylinders have been machined ALWAYS DOUBLE OIL AFTER AN OVERHAUL! If you do all of this, most times it'll be good to go.

[Fast_XC]

Also, check your carburetors and make sure that they are clean and that the float height is set properly. Sludge in the carbs will cause the motor to run lean. I would also look to replace the upper crankshaft seal, if it is bad the #1 cylinder will be lean. Also check the condition of the crank where the seal seats. Make sure the upper crank bearing mount is sealed well to the crankcase also make sure that there is not excessive slop in the bearing or the seal won't be able to seal to the crank shaft.
Good luck,
Neil

[jgwufgator]

Could this be the lean running #2 cylinder because of the undersized jet?

[ChampioNman]

While it is down, look at the piston and the connecting rod, on top of the piston it should say port exh this better be facing the ehaust port or towards the center and also make sure the oiling port on the conecting rod is facing up towards the flywheel. I'd pull the sleeve out and put a new one in just incase. Check the crank journals also. Shouldn't have let go unless they didn't use the main bearing alignment jig. Too many variables to know with out seeing pix of the failure.

[SEAHORSE]

Was the bottom crank seal replaced and were there any signs of rust or water marks on #2 crank or rod and the bottom main bearing?

[ChampioNman]

If you're in Goodlettesville you have a great wrench in your area, Rusty63 at MCM marine. I know another good wrench in Old Hickory at Old Hickory marine. He ain't the most pleasant guy to deal with but he is a good wrench. Ask for CW.

[ringo]

The bottom crank seal was replaced and we did not not see any signs of rust or water.

[RUSTY63]

Give me a call at the shop, I will try to help you with this problem.
615-443-5300

[billofbourne]

I have headr that there is a cooling water circulation problem that evinrude wont admit to. The top two cylindars dont get enough cooling water at high loads. One of the Remanufacturere is modifying the head to solve this problem and claims that if you look at the newer 2002 and above heads you can see the same modification that they make on the older models. Go to riversidemarine.info and give them a call

[ChampioNman]

Heard of, could of, should of, would of, Billofbourne, You seem to have a problem with the big block V-6's of all your 3 post you have someway or manner condemed the motors via hearsay. If you have intimate knowledge of these motors like we do then please refrain from derogotry statements unless you know all details. Thanks the management!