Here I go again!

[viper1]

First of all still the 1989 Starcraft 3.0 L 181 CID. When I got this boat it was getting too hot at idle with muffs. So I changed the Thermostat. Also decided to pull out drive when i found the bellows to be shot. So changed impeller also. Also the water house too with the bellows. Now all back together. But when left at idle it still gets hot. Not positive what the thermostat should open at. But its the recommended one. I figure by 200 it should open and temp drop. But its not.
Is there another way to check water flow through engine? Noticed a little blue smoke when first running too. But it disappeared after running a short time. So any Ideas?

 

[Alumarine]

You changed the thermostat. What temperature did you get?
Are you sure your gauge is right?
Try measuring the thermostat housing and manifold with a temp gun.

Do you have a heat exchanger or does it cool with lake water?

 

[s.hadley81]

Check the water pocket in the drive if someone overheated it coulda melted also if it was overheated the exhaust flapper coulda melted and be stuck somewhere my guess would whoever had before you overheated it and that's two things that could melt from a overheat

 

[viper1]

Well it was over heated as the impeller was melted. Some of the rubber was molded to the housing like plastic. Didn't see any signs elsewhere of pieces though i will check. Water pocket housing was melted. So I got a gasket and swapped it out for another. The thermostat was 140 degrees. I am going to pull it and check if woking. The engine sucks water from lake not closed. I dont have a temperature gun wish i did. I was told I could pull the intake hose at the thermostat housing to check if out drive is ok. Up to 15 seconds I believe. Haven't checked the flapper but will as soon as i locate it. Any ideas on how to be sure the circulating pump is working also. Other than just changing. No doubt i got the shaft on this deal. But I want to restore it any way. So drive and engine is a great place to start. Then i can put in water to see if it sinks! Joking .... at least I hope. LOL! Im at a point now I cant take his word for anything he said.

 

[Fishermark]

...Water pocket housing was melted. So I got a gasket and swapped it out for another. ...

Just to be clear... the water pocket cover is not located where the impeller is. It is at the top of the copper water tube - in the upper unit. Is that what you meant when you said you replaced the cover?

Another thing to check is the condition of the manifold and riser / elbow.

 

[viper1]

Yes the water pocket is in top half. Well sorry took so long to get back. But this weather makes it impossible for me to get out. Thats why i love Erie when Im there I can breath and have fun. Unless the wind stops and lake goes dead. But we know thats bad fishing weather any way.
I did go out to day 5 minutes out and 20 minutes in. I am going to try it this way. But to the point. I pulled the intake hose and the exhaust hose off thermostat housing. So if out drive wasn't pumping id put it back on and check exhaust. Well when I pulled the exhaust host bone dry. So I continued. Started up motor and ran about 10 seconds. Not a drop coming out. So i shut it off.
So from this I believe I need to pull off out drive. Run water from a garden hose into the intake hose to flush into a bucket. I will check for chips in that water. If it wont flow I figure the elbow between drive and engine is plugged tight. If water flows freely i will check to make sure the oring between the outdrive and trans is still in place. Then all is left is to check impeller again. But pretty sure it is ok. Unless being plugged it burnt back up. Oh and ill pull the intake screens and make sure their not plugged. I'm guessing that impeller I took out is the cause and its plugged. As it lost 1/4" all the way around.

 

[viper1]

Ok now! I removed out drive. Ran water from intake hose at the thermostat housing. Water ran good and clean. So I decided to run water thru the exhaust manifold to see if it was blocked. Well about a nickel size piece of melded cooked impeller come out the exhaust hole. So evidently some how it went thru the block or some where. This dont make sense to me. Thought about throwing it back together. But if the hose blew it out i'm thinking something is still blocked.
Can the new impeller be burnt up since water was blocked? Should i pull the lower and redo the impeller again? Thinking also the whole motor and drive should be flushed with water before reassembly. Not sure proper procedure for that. Still don't understand the exhaust getting a piece that big and why water didn't pump from drive to thermostat when i removed the hose.

 

[s.hadley81]

If the water pocket is melted it's probably distorted and might not seal right but usually that shows up on high rpm overheat if you want you can put a clear hose on the hose from transom to the t stat and look for air bubbles you should have a good solid stream but on muffs you probably get bubbles anyhow so that's one for in the water but it sounds like you might be on the right path with finding impeller pieces

 

[viper1]

No hose needed. I removed it with the out drive buried in a tub cut from a 55 gallon drum. Started motor and not one drop come out in 5-10 seconds. Now I spotted another problem. Gear lube in my new main bellows. So figure shaft oil seal is bad also. Looks like I'm going to learn how the upper outdrive unit is built also. Any tips? Honestly I have the Old out drive upper. It had some bad seals also but it was the lower ones. But its off and apart. Also it was recently a new unit before he over heated it. So gears and such should be excellent I hope. Also figure if I should get over my head I have another to get rebuilt somewhere. LOL!
Question??? Does this unit need the lower removed before the upper shaft is. Or does it matter?
Looks like the out drive will remain off. So Im going to flush the motor while waiting on tools and parts. Figure I'll attach a garden hose to the engine where the intake hose goes. Not sure if using full pressure of hose will be too much. Any one know? Figure I can start and run motor that way. And make sure it dont over heat that way. Should also flush any thing bad out.
What do you all think?
Also let me know if the engine overheats on it own.

 

[s.hadley81]

I have a piece of copper pipe with a 90 and a garden hose fitting that slides into the intake on the bell housing on the transom to run without my drive on I just slide it in and I put a bungee on it so doesn't fall out but I've run my boat like that without my drive plenty and it works great if you can sweat copper it only takes a couple of minutes to make and it's nice to have but as far as resealing your drive it's not that hard with a good manual but there's a couple special tools you need that aren't cheap so you might wanna take look at how much they run my dad had them so I don't know how much they are you could also look into stern drive engineering(I thinks it's Sei.com) they sell the whole drive for around $1300 and you can buy the upper or lower separately and they come with a 3 year warranty that covers everything even if you hit rocks