nissan water circulation problem nissan 6 hp

thanks paul for reply i have different issue now,itook engine to have lower end put by proffessional.no water coming out of telltale peehole,early before putting lower end on i knew this already.i replaced thermastat,impellor,waterpump top cover,before i put lower end on first time i hooked up garden hose to bottom of powerhead with adaptor,water came out of every oraphice like a firehose,telltale,exhaust,and water pump tube i replaced waterpump cover because i noticed hairline cracks from over tightening so i got new one put backtogether then had problem putting lower end in .i did twice before by myself no problem. this time i did not have magic, took it to shop they test ran it said no water at peehole itold about all passages being wide open .they said maybe crack in exhaust passage in head causing water to bypass and not going through engine. or idid not replace water pump correctly,is there any thing in bottom half of waterpump that i did not replace that can cause this

If the water tube is not engaged with the upper wp housing, that could happen. One must be certain that the water tube engages the grommet on top of the wp housing. But most common is a bit of debris in the pee port. You can check that by inserting a stiff wire or monofilament fishing line in the telltale port while the motor is running. The telltale pee port is only an indicator that the water system is pressurized; has nothing to do with the thermostat, and the motor can still be cooling OK. Is the motor overheating?

water was shooting out of telltale like a firehose when i hooked up hose to power head why is there reason to believe its plugged when water is coming out so freely just before installing lower end .while lower end was connected i did stick wire up telltale before hose was applied which was advised to me did not make muuch difference it would just squirt a little.so then i decicided to hook hose up then all passages seem to be wide open.i paid mechanic to install lower end u think he may have installed wrong it cost me $100 bucks.when i installed lower end water tube was going into water pump quite easy .icould see it going in with no problem.is there anything that could be broken in lower haif of waterpump,yes motor was over heating prior thats why i started all this mess

i forgot in reply to ask about what marine mech.said aboutcrack in head causing water to defert not going to telltale

Is it overheating now? Was the whole wp kit replaced? It would have to be a whopper of a head crack to not allow water out the telltale. A piece of debris could rattle around in the telltale port chamber, occasionally blocking it.

i replaced top cover because it was cracked plus impellor,what about bottom half i did not replace,back to peehole i s tuck wire up prior to new water pump and after install no difference,butttttttt when i hooked up hose to power head adaptor water was coming out of peehole like a firehose,if there was a crack in exhaust would nt it also bypass peehole

Is it overheating now? Did you replace the stainless cup inside the top wp housing? Did you replace the stainless wear plate below the impeller?

Also, is the compression good?

they said compression is fine ,i didnot replace steel gasket i did that last year ,it looked fine what can go wrong with it if it not cracked anywhere,yes i replaced top cover which has new stainless cup where impellor is seated

Is the motor overheating?

Yes i was told

Then you're probably not pumping to the powerhead. If the water tube is not engaged with the upper wp housing, or if the grommet that the tube seats into is missing/damaged, that could happen. Or... if a bit of impeller broke off and jammed in the water tube.