1970 EVINRUDE 4HP Model # 4036

I just bought this motor about 3 weeks ago. At first it took me about 10-20 pulls to get the motor cranked. I took to a local boat dealership/servicing place and they found that the carburetor needed rebuilt. After I got the motor back today I took it out and it cranked on the second pull. It ran great for a while, probably 10-20 minutes or so. Then the motor over heated and shut off. After it cooled down I cranked it again, needless to say it shut off after a few minutes. After I got it back home I took it to my shop pulled the foot off of it to see if it was the impeller. It seemed to be all right, but I’ve heard just because it looks new doesn’t mean a thing. As I was inspecting the impeller I noticed a small gap between the impeller and the wear plate at the bottom. The gap looks to be around .001 to .004 thousands wide. Is this normal? <br /> Also I hooked up a small hose to the little tube that runs up to the motor block and tried to blow through the tube to see how easy it was. There was quite a bit of resistance. Is this normal?<br /><br /> I hope that I have explained myself good enough for someone to help me. I'm new to these things and any help would be greatly helpful.<br /><br /> The water comes out of the same 2 rows of holes that the exhaust comes out of.

Re: 1970 EVINRUDE 4HP Model # 4036

There really shouldn't be any space on the impeller top bottom surfaces. As the top is put on it should squeeze the top and bottom of it to the housing to make a good seal so the working edges can function properly. The impeller housing is only semi round making one side seem loose to the impeller while the other side may be all squished looking. Thats how they work.<br /><br />It may have a thermostat that is frozen shut. Or it could of sucked up some vegatables or a shredded impeller from before and have a plugged passage.<br /><br />Keep investigating and find a manual if you can.