HP500EFI problem....

[Flyinbowtie]

Perhaps pieces of the raw water pump impeller from previous owners misuse is floating around and blocking circulation.

CC

This is what I think he is gonna find after all he has already done.

 

[mjc]

Of course there's always that "nature of the beast" deal. That motor may just run hotter.


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could be I only have one and mine runs around 170-180 all the time.

 

[kevnmcd]

Of course there's always that "nature of the beast" deal. That motor may just run hotter.


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Except that the temp goes up and down....if it stayed at one temp, say 170 all the time, I would agree. But that still doesn't answer the big difference in water pressure between the two motors.

Perhaps pieces of the raw water pump impeller from previous owners misuse is floating around and blocking circulation.

CC

This is what I think he is gonna find after all he has already done.

Any pieces of the impellor would have to have gone through the oil cooler then through the fuel cooler and then through power steering cooler before getting to the block and then be big enough to plug it up. Not that it is not possible, it just seems unlikely.

 

[Kleptow]

Have a copy of that advisory or know where I could find a copy to look over?

Sorry I can't find my copy, but you should be able to access it here with your serial number or model info (http://www.mercurymarine.com/parts-and-accessories/parts-catalog/)

Mercury has plugs to close some of the pickup holes on the drive to alleviate the low pressure issue.

 

[SKIDMARC]

Man reading this thread, I am sure glad I only have 1 motor!!

 

[kevnmcd]

Man reading this thread, I am sure glad I only have 1 motor!!

Just the opposite for me....with 2 motors I always have a spare.

 

[kevnmcd]

Well, changed the circulating pump and back flushed the block and got a little better pressure but still not enough and it still is overheating! I guess we will just have to live with this for the rest of the summer and will probably pull the intake/heads off this winter and see if we can figure it out. So much for buying bone stock motors and expecting turn-key results!

 

[DaveC]

Maybe you covered this but did you drain the blocks from the lower drains??

 

[kevnmcd]

Maybe you covered this but did you drain the blocks from the lower drains??

We pulled one of the lower plugs in the block to connect the pressure gauge and the water coming out was clean and clear. Didn't even have to put a wire up there to dislage any sand or anything. So pretty sure there isn't anything like that up there.

 

[kevnmcd]

Figured it out. It was the tstat housing. My mechanic decided to just swap the entire housing and tstat assembly on both motors on Thursday. Took it out on the water Friday and Saturday and the other motor was now getting hot. Glad to have that issue resolved. Now just need to figure why one motor is vapor locking and one isn't. If it isn't one thing it's another. :bash:

 

[2FORCEFULL]

Figured it out. It was the tstat housing. My mechanic decided to just swap the entire housing and tstat assembly on both motors on Thursday. Took it out on the water Friday and Saturday and the other motor was now getting hot. Glad to have that issue resolved. Now just need to figure why one motor is vapor locking and one isn't. If it isn't one thing it's another. :bash:

right freak'n on Kev'n:thumbsup

 

[kevnmcd]

right freak'n on Kev'n:thumbsup

Thanks Steve! I knew it was going to be something simple and stupid and it was just a matter of finding it. Only took some time and $$$ but oh well, that is what boating is all about...right?

 

[steamin rice]

Good news that you figured out what the problem was.. One thing I have noticed with twins is that it seems like more than 2x the maintenance. I have had to chase down several minor things over the years, maybe I notice things more since I always compare things between the 2 engines and if 1 is different I want to figure out why. :thumbsup

 

[kevnmcd]

Good news that you figured out what the problem was.. One thing I have noticed with twins is that it seems like more than 2x the maintenance. I have had to chase down several minor things over the years, maybe I notice things more since I always compare things between the 2 engines and if 1 is different I want to figure out why. :thumbsup

Exactly....when you have something to compare side-by-side it is easy to notice slight changes. Either way, this one is figured out now. :thumbsup