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Johnson 140 1994 Overheat help

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Bob Borchardt

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" I have a 1994 Johnson 140 th

" I have a 1994 Johnson 140 that overheats under load. I've tried eveything. She is perfect when idling and below about 2000 rpm, sits at 140 deg (have 2 temp guages, 1 on each bank of cyls) and doesn't miss a stroke when you get on it. BUT, it will overheat (200 deg & horn screaming) on both guages within 2 minutes after you go to plane. Cools off quickly after you drop to low rpm's. I've replaced the thermostats and the diaphrams, and the water pump. The passageways look clean. I'm stumped. The only odd thing is the water from the pee tube seems to be too strong - not just a gentle flow. Any help is greatly appreciated. Maybe a water flow diagram so I might look for blockages??? Thanks so very much! "
 
" there should be two water da

" there should be two water damns in between the cylinders.
Pull heads, using old Johnson @ Evinrude twin line gas hose, or equal, cutt double line into single pieces, using a standard wood pencil, to measure depth of passage between cylinders, ie... 1-3, 2-4, there should be a small boss or half circle looking machine mark in the water passages.
Use pencil to measure the depth of the passage. Should be @ 1-1/2 - 2". cut section of hose this length & insert into water passage. (each bank should need 2. this will slow the water down enough to let it cool. This was a big problem on the 77-80 v-4's. "
 
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