1981 Johnson 90 HP overheating, but not all the time

ranger335

Cadet
Joined
Sep 6, 2025
Messages
24
I screwed up and only ordered 2 water diverters. Somewhere on here I've read what size fuel hose works as a replacement. Can't seem to find it now that I need to know.
 

ranger335

Cadet
Joined
Sep 6, 2025
Messages
24


Found it!
 

ranger335

Cadet
Joined
Sep 6, 2025
Messages
24
So, I started it up yesterday afternoon. At idle, it backfired, something it had never done before. When I placed my hand on the exhaust cover and it shocked me, I thought the backfiring was because one of the coil wires was almost off the coil. That was some of it, but it still backfired some. I let the motor run on muffs for about 20 minutes. The port side seemed to heat up more than the starboard. Hotter but not hot. When I retorqued the head bolts, every one of them on the port side took a quarter turn or so. What do y'all think? Are the head bolts, the heating up, and the backfiring related? Might be a week or more before I can put it in the water.
 
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