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Evinrude 40hp 1973 model#40355D - Water Problems

G

Gorto72

Member
Ok I have a little problem and hope someone out there can help. 1st does anyone know where the thermostat is located on this particular engine (only place I havent looked is behind the cylinder head cover) ... 2nd I fitted a new waterpump and when startted it was pumping like a fire hose (Brilliantly) then after a few minutes water stopped and power head startted to heat up. I guesed I either slipped the pin on the impeller, didnt align the water pipe back into the water pump or maybe a blockage..
I checked it all 3 times and its all good even connected a hose to the waterpipe and it was flowing but I have a suspision the water pipe in the exhaust housing may be worn.. Is the water ment to Only come out the exhaust outlet or can it run back down the copper water pipe...??? Any suggestions please thanks Gorto72
 
You really don't say if you're using a flushette or a barrel of sorts when running the engine. If a flushette, the water must be turned on full force. If in a barrel, trash can, whatever, the water must be 2 or 3 inches above the joint where the lower unit bolts up in order to have the water pump submerged..... having the water any lower, the pump will draw air and quit pumping.

Water exits out the exhaust relief hole (rear of engine, below powerhead), and also out the bottom of the engine near the prop.

Check to see if the water tube might be hitting the edge of the pump grommet, causing it to fold over.

If the water pump checks out okay and you have sealed the plate to the lower unit and the impeller housing to the plate to prevent having the pump draw air, it's possible that someone at one time has hit the water tube when installing the lower unit..... forcing the copper tube upwards.

Remove the lower unit and measure from the sealing surface of the lower unit up to where the bottom of the tube should seat within the water pump grommet.

Now, put a straight edge across the bottom of the long exhaust housing, then measure up to the bottom of the copper water tube.... the measurement should be the same. If not, the tube is bent.
 
Joereeves - thanks for the tip on the bent pipe idea will try it today.
Racerone - I have checked it all and all is good, Have used all factory replacement stuff, Its confussing a little as it was running for about 10 minutes and then stopped
grrrrrrrrrrr

I will try the higher water level idea but short of that Im thinking bent or worn water tube.

If the water tube needs to come out, is it a push in type and sealed with an O ring from the bottom of the exhaust or do I remove the power head.
thanks Gorto
 
SOOOOO happy to hear that it comes out from the bottme....fewwwwwwwwww...lol
I've ordered a new pipe and should have it next week..Thanks for your help..
 
Ok, the moment I applied a little pulling to the water pipe she came straight out, only problem was half was still inside...
I have removed the powere head and found the pipe wouldnt have come out anyways, as it has a flaired top and slips down into the exhaust leg and Not pushed up into it as 1st thought..
anyways, I only broke t bolts off, so a little effort on my part I will have them re tapped and ready to go...
Again thanks for your help people, Loven how everyone gets in and helps with info and suggestions..Keep it going... Gorto
 
Oops! That got by me (flared top of water tube). All of the previous 40hp models simply had the water tube inserted (pushed up into) up in a grommet just under the powerhead. The 1971 model was the very first 40hp model that incorporated that unneeded stupid over enginered top flared water tube design which required removing the powerhead to simply remove/replace the water tube. My apologies for that goof Gorto, it was not intentional.
 
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Are we 100 per cent sure that 73 was the FIRST year of the " flared at the top tube "-------I would like to know for next time.
 
Oops again..... Meant to type in 1971 pertaining to the 40 hp models as I knew that 1970 was the very last dual water tube design manufactured. I edited my reply to reflect that change. Appreciate the reminder.
 
Joe I am more then happy to appreciate your help (right or wrong..lmao ) na I had a gut feeling about it and even though I didnt want to take the powerhead off, I did want to. This allows me to at least find any other problems such as ( the plate gasket missing and the lower seal spring on the crank was also brocken) I dont think the spring was much of a biggy but I will replace it anyways..
A lot of the old bolts are rusty steel so Im gonna retap them and replace with stainless bolts and washers. You'll get a laugh outta this, I was cleaning my bench and after rebuilding the carbbi. I notice a shinny little piece and relised I dropped the fuel needle and I just hope the engine runs as good as it did without it, when I put it back in...grrrrrrrrrr I should know better then to try do stuff whilst having a coffee and talking to the mister of love, war and finances...
 
Gorto.... Yeh, that spotting a engine part laying on the workbench after getting the engine all back together can really be distrubing to say the least.

Fuel needle? Exactly what part is that?
 
Not having the float needle valve installed results in a flooding carburetor condition. Your engine ran in that condition?
 
Owe god why do I tinker when I should just save and buy new...Anyways i first find the water stops pumping (waterpipe was broken), removed the powere head and cleaned everything...then I descover this..looks like the cast has melted rather then corroded. above the water pipe and below the head under the plate. so this is what Im thinking...
I am a boilermaker by trade and trying to reweld this would be a nightmare. Just trying to match the compasition in the metals alone could lead to totaly stuffing it all.
So, I was thinking of using a 2pak based automotive steel epoxy. This stuff is hard as and long lasting..any other sugestions..Thanks again...owe, also snapped 3 more bolts...still havent got cranky yet and as for the needle problem in the carbi, I didnt forget to put it in. I just put the old one back in..lmao
 
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