2 stroke spark plug diagnosis needed

abovebored

I found this whitish crusty buildup on cylinder #1's spark plug electrodes. The other 5 plugs look normal. The motor is a 1996 Johnson 175. It runs good, idles good, has good compression on all cylinders, This plug has less than 100 hours of running time. Sorry pics are out of focus, Any ideas regarding the cause would be greatly appreciated,

Fishinjeff

Looks like burnt oil deposits.  Does it have a oil injection?  2 stroke?

abovebored

Its a carbureted 2 stroke with premixed oil/fuel. I also thought it was "ash"  deposits, but why only one cylinder with this problem? I always use quality oil and fresh gas with a good filter.

Slough

May not have enough spark ( plug, wire or coil). I would try a new plug first and maybe swap coils with another cylinder.

abovebored

Thanks for the input guys. After more research I discovered that the buildup on the plug is actually salt. Evidently, there is a known defect in the block casting from the early years of the ocean runner/pro series 60 degree v6 motors which caused a crack in the block, allowing water intrusion into the #1 cylinder. I did read that someone successfully repaired this by accessing the crack under the water cooled voltage regulator and filled it with JB weld, If anyone has any additional information about this I would be very interested to learn more. Thanks again.

abovebored

Also, the original year I posted was incorrect, its not a 1996 but a 1992 in fact (before they resolved the problem apparently)

livebait

If memory serves me right the 1992 175 had o-rings at each cylinder rather than a head gasket. Sounds like the upper ring is a bit shaky. Part number 0335523.

livebait

what was the problem or still researching?

abovebored

   After getting steered in the right direction it appears the o rings have seen better days. #1 was was deformed and crusty. This motor has no head gasket just o rings, I changed all 3. The cylinder walls are still smooth,,hopefully caught it in time. After finding out about the defective blocks I was really starting to get bummed out so I was really quite relieved to find the shaky o ring. Thanks livebait.

Fletch

Yep, white like that usually means water in the mix. I had a 175 Oceanrunner back in the day that had the defect. All OMC was going to offer was a new block (just the block). Didn't want to do the re-build route. Fuzzy memory but I think I wound up getting a short block from them but still had to come out of pocket a fair amount. Not as much as new but not free either.

livebait

if that motor has been running since 1992 it doesn't have a factory defect block. But I do remember the 175 "FastStrikes" were an accident waiting to happen. Made good money back in the day on them. Fast as the devil, thirsty as the devil, and subject to let go over 5,000 rpm.