Originally Posted by AllDodge (Post 4678883)

To rule out the drive, could you swap the drives and see if the heat issue moves with the drive?

Originally Posted by Bobbyyeah93 (Post 4678879)

This may be a long shot but my neighbor had the same issue with his alpha set up, it ended up being a plastic tube that is inside the outdrive it melted and bent in the middle you couldn't tell until it was removed other than that Id look at corrosion where the hose comes off of the transom assembly they can corrode shut over time. You may want to remove the inlet hose coming off the drive to make sure the impeller is pumping water it may help you find the issue also be careful running it without water going into the drive the impellers can burn up quick. Wish you luck hope you figure it out

Originally Posted by Gone Fishing (Post 4679054)

Hi - yeah, did think about doing the. The rotations are opposite, so would have to put them back, but I did consider. Thanks!
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Originally Posted by AllDodge (Post 4679087)

Oh, could also just swap the props

Originally Posted by muc (Post 4679100)

no no no
that will ruin the standard rotation drive.

Originally Posted by Gone Fishing (Post 4678875)

Thanks - the risers overeat at idle, so the bulletin isn't relevant. The plastic sleeve i the thermo housing was inserted correctly (I defo wouldn't make a mistake like that). It s design 2 (as posted).

Originally Posted by Gone Fishing (Post 4678874)

JUST TO RECAP GUYS (as a lot of questions and referrals are about things I've already addressed)

"...risers getting very hot, very quickly". "...impeller is good as new". ".. replaced the 160 stat and gaskets!. "...replaced both risers with new". "...removed circulation pump and checked (OK)" "...removed and checked PS cooler (OK)". "...replaced exhaust flappers". I have now narrowed the problem down to being OUTSIDE the boat (leg). No water coming in the boat. I rigged up a hose direct to the thermo housing inlet from the leg and the engine runs fine, risers warm/cool and engine running at around 165-170 constant.

Originally Posted by Bobbyyeah93 (Post 4679107)

When you replaced the impeller was there any chunks missing? They can make it into the motor if they come apart depending where the oil cooler is located i had over heating in one of my risers before because a piece of the impeller was stuck behind one of the ball check valves on the thermostat. I'd start pulling all cooling hoses and looking for issues, also try taking the block drains out if you can and maybe pulling the risers off (you'll need new gaskets though). Is this a through transom exhaust or through hull?