evinrude 140 crossflow troubles

U

usmma2013

Member
hey guys,
Just finished rebuilding an evinrude 140 crossflow v4. The powerhead on the engine was scored and needed a hone, I had a spare powerhead with good compression. I gave it a light hone and new rings and used all the carbs, fuel pump, and electronics from the original engine. I started it up and after about 2-3 minutes got an overheat alarm. I shut it down and the port head (from behind the engine, looking forward) was very hot to the touch, the stbd was slightly warm. I checked the t-stats they were fine. I also disconnected the water hoses running from the block to the tstat housing and almost the same amount of water was flowing out of each head. Next, checked the plugs. All on the stbd side were fine, the top plug on the port side was clean, like water intrusion. Now for my question, what could be going on? I'm hoping someone says something like the head could be cracked and all I have to do is put a new head on (I have several extras). The engine had all new head. exhaust, and water gaskets.
thanks in advance!
 
How are the water diverters in it? I know that most of the early cross-flow engines had pieces of hose wedged into the cooling jackets to divert the water flow to help with cooling.
 
well, they're present in that head! not much else to see i didn't take them out to inspect. I'll pull one out tomorrow. Is water supposed to flow around them at a reduced rate or are they supposed to block the water completely?
 
the manual helps too! the deflectors are supposed to direct water all the way around the cylinders before exiting the block. I'll replace them tomorrow and report back
 
I cleaned the bleed holes, replaced water deflectors, cleaned water passages etc. The head gasket is brand new.

I ran the motor again today and the hot head ran much much cooler. I could hold my hand on it for 10-15 seconds at least if not indefinitly. The water exiting the head was ~ 110 degrees. This was on the hose at about 500-600 rpm, in gear, in a bucket. The cooling water on the hose was @ 80 degrees. The other head was lukewarm and cooling water likewise. I'm not sure why one's hotter than the other but its not overheating.

Something else that I didn't think could affect heat this much...but the 'hot' side has one new piston and new rings on both pistons. The other side has the original rings. I honed each cylinder just enough to get the cross hatch back. I added some extra oil for the rings to break it it's about 40:1 right now. Could the extra friction be bringing up the cylinder temps?
 
nymack right it was fine when i got it out on the water. however, then I discovered another problem. The motor will idle great but when you give it throttle it doesn't rev up much at all, maybe 1800-2000 rpm. The bulb stays hard and the timing is advancing and carbs are opening.. Compressions @ 120 on all four. I'm going to test the spark soon as i get a jump tester
 
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