No water going to HX

[Porchhound]

Background: Engine was working when I brought her to this marina in Fall 2022. Good stream coming out exhaust.
Yesterday I changed out the impeller...old one looked good with no pieces missing, supple.
I cleaned the cover plate and removed the old gasket residue, placed on flat surface and lightly sanded with 220grit...same with impeller housing face.
Replaced with new impeller and new gasket.
Opened the sea cock and started the engine...just a trickle of water coming out exhaust...temp never got over 145 after 10min.
Re-checked impeller: some water came out when I removed the face and gasket...back in with impeller and gasket.
Started engine...same issue.
Tried to check sea strainer but I don't have a wrench to fit that clear plastic housing but there was water in the strainer.
Removed hose going to HX...no water coming out.
I've reviewed every article I can find so now my mind is going in six directions.
Where do I go from here?
Also the exhaust blue hump hose seems to be bulged out (ballooned.)

[Jon W]

Simple things first- you verified the raw water seacock is fully opened?

[Porchhound]

Until I can get the sea strainer off I can't say for certain, but there is water in the strainer, and the strainer looks clear. Should I remove the hose and then open the strainer slightly to see?

[Jon W]

In your post asking about a wrench, the photo shows the seacock is closed. Did you turn the handle 90 degrees to the open position?

[Porchhound]

I did, but I closed it when I was trying to remove the strainer.

[waughoo]

I always put some dish soap on the impellor when I install it.  This gives the pump some lubrocity until the water makes it there and gives me a visual signal that the water has made a complete circuit when soap bubbles appear at the exhaust flow.

[Porchhound]

Dishsoap was a great idea. I ran to make sure water getting to impeller, then out of impeller. After about thirty seconds, soap bubbles began appearing out exhaust along with good stream of water. Don't know exactly what happened, but maybe pulling the plug helped prime the pump, or there was some debris in the way...or it was the old lady down the dock who was throwing chicken bones and chanting for me.

Anyway...if the answer ain't on this site, it's an unsolvable conundrum. Thanks for everyone's help.

[KWKloeber]

Dishsoap was a great idea. I ran to make sure water getting to impeller, then out of impeller. After about thirty seconds, soap bubbles began appearing out exhaust along with good stream of water. Don't know exactly what happened, but maybe pulling the plug helped prime the pump, or there was some debris in the way...or it was the old lady down the dock who was throwing chicken bones and chanting for me.

Anyway...if the answer ain't on this site, it's an unsolvable conundrum. Thanks for everyone's help.

The plug is theoretically in case one needs to prime it. You may have had an airlock and a dry impeller having enough air leakage to not create the vacuum needed to self-prime.   Is the pump below the waterline on the 34? On my engine I can crack the pump cover to verify the pump is getting water.

Remember also it's not always all about the strainer - the thru hull can get weeded-up as well.

Remember also, righty-tighty/lefty-loosey (looking of course at the END of the strainer.

You mentioned looking for a diagram? of the cooling?   What precisely were you referring to and I can probably point you to it.

Careful Dave - If the answer isn't on the forum - well, we just make one up.

[Porchhound]

The pump is below the water line. I'm going to have someone dive on the boat for zincs and cleaning. I'll have them inspect the thru hulls while I'm at it. It sat here for nine months. I did double check my righty-tighty maneuver...just in case!

I remember seeing a raw and fresh water cooling chart where corrections had been made on the one in the manual.

Regarding made-up solutions, I'll happily take a tall tale when facts are beyond reach.

[Stu Jackson]

Strainer - good idea.

Take off the hose from the thru hull/strainer to the rw pump at the pump, use a dinghy foot pump to BLOW BACK through the hose, will clear out the thru hull (usually); diver should, too.    Depending on your strainer arrangement you could also do this under the head sink.

After that, SUCK on the hose to get water through it, it's the best way to prove it, because yes even though the pump is below the waterline the tight fit of the pump faceplate does not allow water to flow, even "downhill"; it's a reality, and the HX is uphill, too.

[KWKloeber]

I remember seeing a raw and fresh water cooling chart where corrections had been made on the one in the manual.

Dave
I had placed my corrected page in the m-25, et al, 1989 Owners Manual on the wiki site "manuals" page.  Unfortunately you have to get to the manuals page via a convoluted path because the link on the main Wiki page is broken and until "someone" will fix it, it remains that way. 
Simple fix, but I can't get it fixed for several years.

[Porchhound]

Thanks...I'll go find it. I knew I saw it somewhere!

[Ron Hill]

Porch : Go to an auto parts store and get your self a strap wrench.  You are going to need it to get that strainer apart to eventually clean it out.  Be careful because there is a SQUARE "O" ring gasket between the screw-on bowl and the strainer body that attached to the thru hull.!! Then only hand tighten that strainer bowl!!!

The raw water system is simple.  The raw water come into the thru hull with the strainer, then it goes around the back of the sink head, then in the top back of the engine to the inlet on your raw water pump (starboard side). Then the water is pumped to the heat exchanger, then out of the HX to a Anti Syphon valve mounted on the top port side of the engine (look for it thru the head sink door).  Then it goes from the AS Valve to the nipple on the exhaust riser (mixing with the exhaust gases) into the aqua lift muffler.  Then out the muffler to the exhaust mounted in the port side stern (underneath).   

A few thoughts .

[Porchhound]

Strap wrench worked, very little debris in the filter. I'm thinking I didn't get a prime after I replaced the impeller. Hope that doesn't mean the pump is getting weak, but it runs fine now.

[Stu Jackson]

Did you read reply #9?  Pumps don't "get weak."