Mariner 2 hp outboard engine (1985) not pumping water

there is a pump for sale on e-bay --seller is western furniture (1918) used condition for $25.00 us 2 people watching it but it has a buy now tab
I found this by going google and typing in --fuel pump for mercury outboard motor 3.9 hp-- and the site is www.ebay.tv>sch>ebay-motors-
mariner is also a part of the mercury range so check for mariner 3.9 or 4 hp parts

renew spark plugs,mix up some fresh fuel,put choke on,throttle set at just above idle,pump up fuel bulb by hand till tight,put outboard in a water drum,try pulling or turning on starter till it fires,then push choke in and restart

have you checked the fuel pump diaphrams are ok and are the connections on the fuel tank and line ok ? primer bulb not sticking ? carbs clean ? fuel pump connection to crankcase ok ?

clean the lower unit intake holes and

PUT IN A NEW WATER PUMP IMPELLER!!

mcdevito75 Here, If I;m not mistaken the water pump is in the lower houseing, a big job, let the marina take care of it as the water pump should be Changed only if it doesn"t pump at all.

water pump-
crack in the housing from sitting over the winter with water in it

I would start with cleaning water intake and if you haven't re placed water pump impeller in last two years would do so now ,before you lose a weekend off the water,Hope this helped .

With what you said.get the water pump done.A little bit of rubber is cheaper than metal.If the motor has a few years on it,the pump does need to be replaced.If the motor overheated after a few minutes,the pump needs replacing now.Yours sounds like it's on it's way out.A bit of sand etc. can do a fair bit.Hope this helps

With your lower unit off have someone shift the engine into forward while watching the gear shift select shaft's rotation,let gearshift remain in forward,now place your lower unit in forward and reinstall. In the future just put engine in forward when installing a water pump as there won't be a need to move gearshift

the drive shaft goes down through the water pump impeller and I suspect that the problem will be in the pump
the impeller is rubber and if run dry will melt the rubber into the housing and bind up the shaft
Brute force is a last resort so get all the information you can from a service dealer mechanic