Merc 7.5 tell tail leaking slowly

rookiedave

Cadet
Joined
May 26, 2010
Messages
20
Hi,

Just put my 2nd impeller in today. (cooked the first one) This time it went in so much better. I fired it up and it ran great. A little smokie but it sounded very strong and ran a long time 10 min before I shut it down. I ran it at idle and at fast rmp. it did not even skip one time. Took the cover off and touched the "block" a little warm but not scalding. Only question is the pee hole does not have more than a trickle of water coming out of it. This time I know, that the impeller is installed correctly. What should I do next?
Thankx
dave

I think that water first squirted out tell tail and then began to trickle.
 

huntin dawg

Petty Officer 2nd Class
Joined
Nov 12, 2009
Messages
197
Re: Merc 7.5 tell tail leaking slowly

Sounds like a water passage is blocked. Possibly with a piece of the old impeller. You may need to tear it down and clean all of the passages but for now you can try clearing it by flushing the system through the flush port at the top of the exhaust housing.

HD
 

turtles11756

Petty Officer 1st Class
Joined
Dec 5, 2007
Messages
260
Re: Merc 7.5 tell tail leaking slowly

clear the hole with some wire and see it it starts to run faster
 

DuckHunterJon

Lieutenant Junior Grade
Joined
Apr 19, 2010
Messages
1,082
Re: Merc 7.5 tell tail leaking slowly

Just for clarification, are you running it on muffs, in a bucket, or on the boat in water? My 3.9 and 6 hp Merc's both act the same way. In a bucket (35 gallon, filled about half way) they will just barely trickle. Motor will be warm, but not scalding. Put them on the boat and take it out, good pee stream out the tell tale, motor is cool to touch. I chalked it up to different pressure (motor depth) in the bucket vs on the boat. Both of these have the pickup under the cav plate, so can't say what they would do with muffs.
 

rookiedave

Cadet
Joined
May 26, 2010
Messages
20
Re: Merc 7.5 tell tail leaking slowly

Thank you all,
I have it also in a 35 or 40 gallon bbl. I will also rod and flush it out just in case.
 

snowman48047

Petty Officer 1st Class
Joined
Jul 24, 2008
Messages
371
Re: Merc 7.5 tell tail leaking slowly

I keep a foot long piece of weed-whip plastic on board just for this. I have unclogged that thing a half dozen times. Sand, Clay, weeds, etc...all will clog it so you just get a trickle. Should make no difference whether on muffs, in a bucket or in the lake water should come out the same.
 
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