4hp evinrude cooling issues

[bikebunky]

69 evinrude 4hp folder. won't pump water or very litttle. checked impeller and sealed pump housing. water tubes in place. compressed air thru upper tube and comes out exhaust housing under power head. very little salt in eng. removed head and ran eng in tank spinning with drill. no water coming out port hole in block. put head back on, fired it up and checked head temp. quickly went to 200+ degrees. pulled head and only damp in block. gromets in place between the folding units. impeller in good shape. any thoughts?

 

[SEABEE#2]

Re: 4hp evinrude cooling issues

Had a similar issue with my 69 9.5. Check where the water enters the lower unit. Mine had a meshing along with the sideplate where water is able to enter the lower unit. Also I had a stuck thermostat which did NOT allow water to pass through. Also you mentioned it is a folder...Never seen one in person, but are all the seals in good working order connecting the lower and upper units as well as lined up? Heres a picture of my stuck thermostat (top mushroom like valve should be down not up). Mine was pumping little water while heating up close to 200 as well.

 

[Rick.]

Re: 4hp evinrude cooling issues

Take a careful look at your impeller housing. If it's got much wear it can cause poor pumping. I did not know there was a 4 HP with a folding leg so I learned something myself today. Best of luck. Rick.

 

[nwcove]

Re: 4hp evinrude cooling issues

not a fan of the folders!.....but i would take ricks advice, and inspect the impeller housing and plate. then i would definitely replace the impeller ( unless you already have, or know for sure when it has been....an old impeller can look fine, but when they take a "set", they are nfg and shouldnt even be installed to spin the other direction) jmo

 

[bikebunky]

Re: 4hp evinrude cooling issues

The 3 and 4 hp engines do not have a thermostat. What is the head temp supposed to be

 

[Rick.]

Re: 4hp evinrude cooling issues

You should be able to hold your hand on the top of the head for a 3 or 4 count without any burns. IMO that would be under 140F. for sure. My hands aren't as calloused as they once were. Rick.

 

[colbyt]

Re: 4hp evinrude cooling issues

The 3 and 4 hp engines do not have a thermostat. What is the head temp supposed to be

163 degrees according to the factory service manual. Make sure the impeller pin is engaging the impeller. Sometimes people don't replace those often enough and it does is free spin.

At 163 I don't suggest the touch test.

 

[joelybob]

Re: 4hp evinrude cooling issues

I have 1983 4.5 hp evinrude stopped pumping water so i tore it apart. impeller looked good. but when i put both them together new one was about 1/16 of an inch longer. put new one in pumped perfect. so i dont think you can tell if they are good by just looking at them. just my 2 cents. good luck