I just got this 1975 evinrude 4hp from my dad. I don't know very much about these little guys other than thay seem to be good motors. after running the boat for about 6 minutes the motor gets very hot. I checked the impeller and it seemed to be fine. I cant tell where the pie hole is . I think it is the 6 little holes in the center of the muffler casing, because i can see a little bit of water trying to come out any idea if that's the pie hole, and if any amount of giving water should be coming out?
There is no telltale stream from that engine, Emano. You are correct that the holes low in the exhaust housing are your water circulation indicator.
You should get a small spray out those holes. Sounds like you have some restriction in the water flow.
Good luck, and welcome to iboats.
Thanks alot JB ; for the info on the 4hp . The motor seems to be running very hot.when I do the poor mens temp test on it by spraying a little water on the heads next to the spark plugs it sizzles away in about 6 seconds, but next to the heads on the left side were the recoil is mounted it sizzles away in about 3 seconds.should this motor be running this hot?
Definately not.Check the water intake.Be sure water can get to the head.
Pretty simple motor,you should be able to figure out the circulation.
If impeller has taken a set it should be replaced.If you don't know the age you should replace it.Cheap insurance against a fried motor.
I just fired up my 71 4hp last night and the temp. at the top of the head was 140 degrees F. after running at a bit higher than idle for 20 minutes. Stop running your motor until you get the water pump working right or your going to cause problems. As near as I can tell my motor has no place for a thermostat but I could be wrong. Looked at the parts book and don't see one anywhere. Once you change the impeller you should see a good spray of water out the holes you mentioned. You can also pull the leg and hook a hose to the water tube and give everything a real good flush. I have been working on mine off and on since November and she is ready to go now. Only problem is the lakes here will have ice until the end of April. Best of luck. Rick.
I just fired up my 71 4hp last night and the temp. at the top of the head was 140 degrees F. after running at a bit higher than idle for 20 minutes. Stop running your motor until you get the water pump working right or your going to cause problems. As near as I can tell my motor has no place for a thermostat but I could be wrong. Looked at the parts book and don't see one anywhere. Once you change the impeller you should see a good spray of water out the holes you mentioned. You can also pull the leg and hook a hose to the water tube and give everything a real good flush. I have been working on mine off and on since November and she is ready to go now. Only problem is the lakes here will have ice until the end of April. Best of luck. Rick.
THANK YOU RICK; I am gonna stop running the little guy till I get the impeller replaced and get It cooling right. My question to you is do you think all the cooling water is supposed to come out of these 6 holes mid way down the motor
Thanks alot JB ; for the info on the 4hp . The motor seems to be running very hot.when I do the poor mens temp test on it by spraying a little water on the heads next to the spark plugs it sizzles away in about 6 seconds, but next to the heads on the left side were the recoil is mounted it sizzles away in about 3 seconds.should this motor be running this hot?
Hay JB I took the bottom part out of the lower shaft witch is were the impeller is located I connected a hose to the long tube witch I suppose is used to send water from the impeller to the motor. At that point I did not notice water coming from anywhere! -- SO my guestion to you is were should water be coming out of when I run water into that long tube?
emano: Sorry for the late reply. I have been away. I thought more guys would have answered your questions and I was waiting to look at my manual. If you aren't getting water coming back with a hose hooked to the water tube then you have a blockage somewhere. I would start by pushing a wire up the water tube and see if you can get water circulating after that. You ask a good question about where should the water be coming out. Truth is...I don't know exactly. My manual does not show the water path. I do know this though, it goes up the water tube, around the cylinders and head and then back down the leg. Some will come out the holes we've referred to and some probably goes out the leg with the exhaust gas. My exhaust gas goes out above the prop on the end of the fin. I have the weedless lower unit. My 71 has no thermostat so you needn't be concerned if the stat is open/closed. If you still get no water flow you could pull the head and try mining out a blockage from that point back toward the water tube. Once you get it running I would let the hose run for a good long time and continue to work away at freeing up whatever is blocking the flow. There are chanels on the head that may need to be cleaned out as well. Was this motor used in salt water? Salt water can cause the water channel to plug and that is why the motor should be flushed with fresh water after salt water use. A new impeller is a great idea but I wouldn't put it on until you get good circulation through the engine via the water tube. Best of luck and let us know how it goes. Rick.
The water flow is up the water tube, around the power head. It is then simply discharged into the top of the leg to mix with the exhaust gases. Most will leave via the main exhaust outlets but little will be blown of of the exhaust relief ports on the leg.
If there is not a good flow of water back down the inside of the leg with a hose connected to the water tube then there is a blockage somewhere. It could just be something blocking the water tube but more likely that the water passages in the power head are blocked with scale or corrosion. The passage ways around the head are particularly easily blocked.
To get this all properly clear it will almost certainly need the cylinder head to be removed and the whole power head removed from the leg, but do try a wire up the water tube first.
__________________
..
If it aint broke dont fix it!
emano: Sorry for the late reply. I have been away. I thought more guys would have answered your questions and I was waiting to look at my manual. If you aren't getting water coming back with a hose hooked to the water tube then you have a blockage somewhere. I would start by pushing a wire up the water tube and see if you can get water circulating after that. You ask a good question about where should the water be coming out. Truth is...I don't know exactly. My manual does not show the water path. I do know this though, it goes up the water tube, around the cylinders and head and then back down the leg. Some will come out the holes we've referred to and some probably goes out the leg with the exhaust gas. My exhaust gas goes out above the prop on the end of the fin. I have the weedless lower unit. My 71 has no thermostat so you needn't be concerned if the stat is open/closed. If you still get no water flow you could pull the head and try mining out a blockage from that point back toward the water tube. Once you get it running I would let the hose run for a good long time and continue to work away at freeing up whatever is blocking the flow. There are chanels on the head that may need to be cleaned out as well. Was this motor used in salt water? Salt water can cause the water channel to plug and that is why the motor should be flushed with fresh water after salt water use. A new impeller is a great idea but I wouldn't put it on until you get good circulation through the engine via the water tube. Best of luck and let us know how it goes. Rick.
thanks alot for your time rick. Im gona get some wire, try moving it around the tube and run the hose through it again. And i will let you know how it goes.
The water flow is up the water tube, around the power head. It is then simply discharged into the top of the leg to mix with the exhaust gases. Most will leave via the main exhaust outlets but little will be blown of of the exhaust relief ports on the leg.
If there is not a good flow of water back down the inside of the leg with a hose connected to the water tube then there is a blockage somewhere. It could just be something blocking the water tube but more likely that the water passages in the power head are blocked with scale or corrosion. The passage ways around the head are particularly easily blocked.
To get this all properly clear it will almost certainly need the cylinder head to be removed and the whole power head removed from the leg, but do try a wire up the water tube first.
evinrude 1975 4hp where is the pie hole
Re: evinrude 1975 4hp where is the pie hole
Linear Mode
