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89 200 yamaha overheats

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Miami9557

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Recently at sand bar and shortly after the impeller keyway broke and no water was peeing. The alarm went off and I shut it down and towed it in. I installed new impeller kit, housing, t-stats and poppet valve. The engine still sets off the alarm and the temp goes to aprox,150 degrees. The heads feel really hot and the now when you crank there is no water coming from the pee hole. Prior to this it had a good steam during cranking. Also after the alarm goes off and it cools down there is no flow from pee hole again. I took back apart and all looks good. Could there be some blockage at the copper feed line coming out of the pump ?? Is there a back flow test we can do also to check the water flow from the poppet valve. Please help.. Rick
 
Wiggle the water tube gently. I may be coming apart. Should be very rigid. Are you sure you put a new water tube seal and the retainer back in the pump housing when you replaced it?
 
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Thanks for the reply. The tube is very tight, but there was no seal in the old one that I saw or did the new kit only to o-rings that go on the housing itself. The old impeller housing and the new had a hard plastic type bushing or collar that snapped into the top of it and then the water tube slid in. I did notice that the small vacuum type hose that comes off the back,if you look into the lower unit ,it appeared clogged. I did clean it best as possible. What is its function ?
 
Miami9557 said:
Thanks for the reply. The tube is very tight, but there was no seal in the old one that I saw or did the new kit only to o-rings that go on the housing itself. The old impeller housing and the new had a hard plastic type bushing or collar that snapped into the top of it and then the water tube slid in. I did notice that the small vacuum type hose that comes off the back,if you look into the lower unit ,it appeared clogged. I did clean it best as possible. What is its function ?
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There is a seal under this bushing that you need to transfer from the old housing to the new.
 
Is there a part # of pic I can look at . The old housing did not have a seal on the the water tube that inserts inside the housing and it never ran hot before the key eay brakage,so im abit confused. I did not have any left over parts. The only seals in kit were the above the metal plate that is inserted in the plastic housing and the around the edge of the housing that seal to the plate the impeller rides on. Thanks
 
On top of the pump there is a plastic inset/bushing to guide the water tube into the pump housing. Under the bushing is a seal. Look in your old housings and see if the seal is still in there. This seal does not come with the new pump kits.
 
Thanks . I will order a new seal and try it . Im sure the old had no seal . I inspected it very close before purchasing a new housing and the only piece there was the inset/bushing .Is it an o-ring or an actual seal that sits over top of the housing ??
 
Thanks.I ordered it today and should have for saturday. Anything else that i should be looking for. Someone else told me to run a rod up the water pipe and make sure its clear of any debree. They think the plastic keyway broke because of excessive pressure?? Thanks again .
 
Yes I picked out the remaining piece from the shaft. I was told some aftermarket impellers come with the key way built in the collar . Strange. The new one is a normal key way like a crank. What do you think about cleaning the tube with a rod or hanger for debris.? And still not sure what the function the vacuum style line that runs at the back of the lower unit and runs up the middle of engine.Let me know.. Thanks again.
 
The Yamaha water pump impeller has a Mild steel Keyway. They usually rust into the shaft. Johnson/ Evinrude Ob's have a plastic wedge on the pump impeller..

You should post a picture.
 
Thanks for all the help. I added the seal that was missing and it seems to have fixed the problem. i ran it for .5 hour on the ear muffs and never got over 125 degrees, no alarm. Im going fishing tomorrow for dolphin (Mahi) and will update how it performs in the ocean. I dont have a pic to insert of the plastic wedge . It may have had an impleller from another brand,but its all O.E now. Thanks again.
 
Miami9557 said:
....And still not sure what the function the vacuum style line that runs at the back of the lower unit and runs up the middle of engine.Let me know...
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I believe you're describing the speedometer tube. It diverts water from a tiny hole in the skeg to the meter at your console.
 
Well back to the drawing board. I have no more alarm at idle and I can troll for hours , but my water pressure guage does not budge any more off idle speed and now the alarm goes off 2-3 minutes after I accelerate over 2500 rpms. I reduce rpms and it let it sit for 5 minutes and temp goes down fairly quickly. . Im assuming something has to be clogged because prior to the key way breaking this engine ran very good. I need an estimate if anybody can refer someone to me in the Fortlauderdale /Miami area.
 
Is your pressure control valve stuck open? Was there any debris from the old waterpump that was not accounted for?
 
Well I have no pressure on my guage under acceleration, the temp climbs to 140 or so and I can see alittle steam from exhaust when the temp climbs. If I could confirm the water pressure issue under load issue ,but I went to screw off the brass fitting where the clear that goes to the guage and it feels like its going to break off. Any suggestions. How much is a rebuild or just a head r/r and gasket replacement cost. engine has good compression . 100 + psi all 6.
 
Should I pull heads or is it more of a possibilty that that the clog is somewhere is.??What about the cover in between the heads . The poppet valve is there. please help.
 
Low pressure sounds kind of terminal to me. I think your powerhead is sound but I question whether enough water is getting to your powerhead. Back to the last thing you worked on. Verify everything regarding the waterpump. Then put a water hose the the tube and see if you get much flow out of the t-stat holes. Water may be dumping somewhere in the mid section.
 
Thanks . The water pump has been triple checked , the impeller has some ribs that point into the direction of the flow. It looks idiot proof . Where would the water be flowing. Do they flow thru power head first then channeled thru the heads until t stats open then back down thru the water jackets. ? I was thinking of pulling the heads this weekend but would like to somehow do any test possible before hand. Is it possible it cracked the heads from overheating as a car engine or seeping thru a crack on the headgaskets ??Thanks again for the feedback...
 
Cracked heads no. But I'm thinking you burnt through somewhere and the water is dumping. Just pull the t-stat covers and see if you can get some flow. leave the l/u on and run it on the muffs for a minute. Should be plenty of water out of there.
 
I don't know about your "new style" pressure control valve. Never heard of it before. Maybe that is where your water is dumping?
 
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