tohatsu 3.5 hp can't get a good flow of water

[chestercheese]

Hello people, just need some advise on how to get a good flow of water out of my wee hole, i've checked the impellar and that seems to be good, can blow though the wee hole quite easyley, on start up after about 30second or so i get a good flow, but after about 2mins it starts to spit then stop, if i leave it to cool down and then re-start it the same happens, do you think its the impellar or some sort of blockage?
many thanks and hope to hear back,
p.s my model number is m3.5a

 

[fishndirk]

Re: tohatsu 3.5 hp can't get a good flow of water

That motors cooling system is controlled by a thermostat,...which means water will constantly flow out the pee hole but is only flowing over the cylinders when the thermostat gets above a certain temperature. Your drop in water flow could be when the motor gets nice and warm and the thermostat valve opens then all of a sudden the impeller has a much larger area to fill and pressurize with water, thus a loss in output pressure. Never owned a motor that small so I dont know if that would make a difference but I do know that you can put your hand under the pee hole and tell if your thermostat is working cause you will feel a variation in water temperature every minute or so...any other signs or symptoms let us know

 

[chestercheese]

Re: tohatsu 3.5 hp can't get a good flow of water

hello, thanks for your reply, i sat down and had a think? then i thought i'll take the prop off, put it back in the tub and it did'nt miss a beat, it must have been causing a vacuum in the tub not allowing the water flow, as its a continuous drive,
many thanks again dan

 

[pvanv]

Re: tohatsu 3.5 hp can't get a good flow of water

That motors cooling system is controlled by a thermostat,

Incorrect, No stat.

Try a new impeller, as the side clearances on these is critical, and the prop shaft-driven impellers turn at approximately one-half the RPM of the B model (drive shaft-driven) pumps.

You may also have a leaky head gasket, allowing water to leak when hot. Though that would be rare. Check plug color to verify water intrusion into the cylinder.

 

[Sea Rider]

Re: tohatsu 3.5 hp can't get a good flow of water

If that model has same hose peeing port as the 3.5 B2 model, remove lateral cowl, remove black hose and insert a proper thickness wire upwards block several times, sometimes using compressed air doesn't remove complete obstruction, generally salt crusts if engine was not properly rinsed after use. Don't expect a huge peeing on that engine, just a no pressure constant dropping water flow.

Happy Boating