1984 johnson long shaft 8 HP

Friend installed a new impeller and now it pumps water but out flow is to hot to put your hand in, took it apart and installed new tube seal and another impeller and still same problem, was working ok before surgery. When you open the throttle it slows and smokes.motor has very few hours. Any help would be appreciated.

Why were you putting a new impeller in?
What did the old impeller look like that came out of it?
Did you overheat the engine that you know of or do you think you did?
Answer these questions honestly and we can probably do a better job of helping you.

bengray3 said:

Friend installed a new impeller and now it pumps water but out flow is to hot to put your hand in, took it apart and installed new tube seal and another impeller and still same problem, was working ok before surgery. When you open the throttle it slows and smokes.motor has very few hours. Any help would be appreciated.

Click to expand...

bengray3 said:

Friend installed a new impeller and now it pumps water but out flow is to hot to put your hand in, took it apart and installed new tube seal and another impeller and still same problem, was working ok before surgery. When you open the throttle it slows and smokes.motor has very few hours. Any help would be appreciated.

Click to expand...

[url=https://www.tinboats.net/forum/viewtopic.php?p=346961#p346961 said:

Pappy » 31 Mar 2014, 15:49[/url]"]Why were you putting a new impeller in?
What did the old impeller look like that came out of it?
Did you overheat the engine that you know of or do you think you did?
Answer these questions honestly and we can probably do a better job of helping you.

Click to expand...

Originally replacing the return spring on the recoil starter because it would only return 3/4 friend said might as well change impeller while we have motor apart, was pumping fine old impeller was a little worn but not to bad.

[url=https://www.tinboats.net/forum/viewtopic.php?p=346965#p346965 said:

bengray3 » 31 Mar 2014, 16:03[/url]"]

bengray3 said:

Friend installed a new impeller and now it pumps water but out flow is to hot to put your hand in, took it apart and installed new tube seal and another impeller and still same problem, was working ok before surgery. When you open the throttle it slows and smokes.motor has very few hours. Any help would be appreciated.

Click to expand...

bengray3 said:

Friend installed a new impeller and now it pumps water but out flow is to hot to put your hand in, took it apart and installed new tube seal and another impeller and still same problem, was working ok before surgery. When you open the throttle it slows and smokes.motor has very few hours. Any help would be appreciated.

Click to expand...

[url=https://www.tinboats.net/forum/viewtopic.php?p=346961#p346961 said:

Pappy » 31 Mar 2014, 15:49[/url]"]Why were you putting a new impeller in?
What did the old impeller look like that came out of it?
Did you overheat the engine that you know of or do you think you did?
Answer these questions honestly and we can probably do a better job of helping you.

Click to expand...

Originally replacing the return spring on the recoil starter because it would only return 3/4 friend said might as well change impeller while we have motor apart, was pumping fine old impeller was a little worn but not to bad.

Click to expand...

When I launched with new impeller started at trolling speed for 4 to 5 minutes water looked ok but when I reached back to feel it was very very hot, thought maybe a little speed would help. kicked it up to full for 1 or 2 minutes much smoke and water stopped pumping, slowed to troll for half hour and then pulled it out.

Okay, at this point the only option for you is to pull the gearcase and check.
Make sure the pump outlet lined up with the water tube that leads to the powerhead properly. Sometimes this can be the culprit. The grommet can be caught and folded over, etc.
Since you seem to believe it is running hot it may be a good idea to check compression since the engine was run pretty hard with minimal water. Won't hurt.

This may be a stupid question, but, did you install the drive 'key' for the impeller?

Sticking thermostat maybe?