Yamaha Outboard Head Gasket Replacement

I was having a misfire which was causing my 175hp Yamaha 2 Stroke to run terribly. I went through the steps of replacing the cheapest parts on the fuel side to confirm that it wasn’t a delivery issue. I had reason to believe that there was water getting into one or two of the cylinders causing the misfire. I replaced both head gaskets and while that didn’t completely eliminate the misfiring issue, it did improve the performance of the outboard. Ultimately the misfire issue cane down to an issue with the timing.

[@fishydubsfishing6516]

It's amazing those old boat anchors are still running

[@user-dc1pj7ug7l]

Water jacket most likely your issue. just had to replace mine, head gasket was fine, was getting water out of bottom cylinder also!

[@knightcustombuilds6988]

I have a 96 tohatsu m50d. Its getting water in the bottom cylinder. Ive only had the motor two weeks. Anyways the motor runs decent but is popping when I stick it to jump on pad. Just one pop and then it gets down to business. No misfires etc. But water on the bottom plug. Im thinking that when the previous owner changed the head gasket he either didnt torque it properly or used aftermarket gaskets that weren't to spec. I changed fuel sources and checked and replaced most gas lines etc. Does this sound like a head gasket issue. Motor doesn't over heat.

[@bradj2176]

Did you do the internal annodes? They look like they need replacing, also did you check the block and head with a straight edge to make sure they are flat?

[@AIforbusinessGuy]

I did not replace the anodes …block and head are flat

[@dsciarrino3663]

Sweet Eng

[@AIforbusinessGuy]

Thanks!

[@miguelnieves9926]

did this repair fix your misfire?

[@AIforbusinessGuy]

Yes that along with a timing adjustment