2020 Yamaha 115 vmax cooling issue

[Steve1216]

Need help I have a Yamaha 115 outboard 4 stroke when boat is first started no water out tell tale. If boat sits for more than 24 hrs I have to flush out motor (boat not running) wait 5 min then lower boat into water. Start boat turn off immediately then restart water will come out telltale. It’s like it needs primed. Boat stays on a lift at my dock. If I take boat to restaurant and boat sits for hour I have to start then turn off and restart for telltale to work or start then goose it water flows out telltale. Boat runs fine when water flows. If I start boat and no water out telltale she will over heat. Impeller has been replaced.

 

[boscoe99]

It is not abnormal for there to be a period of time before water starts coming out of the tell tale. A minute's time would not concern me.

Having said that, when was the last time the water pump was replaced?

 

[Steve1216]

It is not abnormal for there to be a period of time before water starts coming out of the tell tale. A minute's time would not concern me.

Having said that, when was the last time the water pump was replaced?

If I let motor run overheat alarm comes on pump was replaced 6 months ago
It acts like it is air locked

 

[99yam40]

check the pump.
something could have happened to the pump in those 6 months

 

[Steve1216]

check the pump.
something could have happened to the pump in those 6 months

There was a new pump installed in spring last year had issue all summer that's how I was able to come up with the start turn off re start and it works replaced pump late summer still had issues
Trying the thermostat just don't feel that could be it but who knows

 

[Steve1216]

Just pulled

 

[99yam40]

looks like you found the problem.
I would be looking at the pump housing also for signs of melting.
kits contain the cup and wear plat along with other good part not just the impeller, but do not have the housing included.
was that a Yamaha pump Kit or an aftermarket one you installed 6 months ago that never pumped properly?

 

[racerone]

How hot does lower unit get in direct sunlight?----Your issue seems unusual to say the least.

 

[Steve1216]

It's very unusual I have searched everywhere and have not come up with anything close to my problem 2 boat repair shops said its the thermostat but they were not yamaha dealers I have a 3 year warranty BUT warranty doesn't cover cooling systems

 

[Sea Rider]

Just pulled

Is it a fresh or salt water use motor, if salt water use, is it religiously flushed with fresh water soon after returning from boating ?

Just in case install a fresh OEM impeller and micropish with finger the liner housing with toothpaste in circular motion till shinny and smooth to your firngerprint Assuming all water passages are impeccable clean motor will pee much stronger. Will be good to remove the thermostat, brush it off with a hard bristtle toothbrush and vinegar if found in excellent condition or replace for a new one if excessively rusted, salted or a combo of both situations..

Happy Boating​

 

[99yam40]

It's very unusual I have searched everywhere and have not come up with anything close to my problem 2 boat repair shops said its the thermostat but they were not yamaha dealers I have a 3 year warranty BUT warranty doesn't cover cooling systems

buy the Yamaha water pump kit, it is just a few dollars more then the impellor by itself and you get the new wear plat and cup and all o rings and gaskets needed.
As I said before,
your impeller is toasted.
deformed and cracked it is not seating properly into the cup anymore.
the wear plate has groves in it.
the plastic housing may also need replacing

You never answered my question on who installed and what was installed 6 months ago

 

[Steve1216]

Is it a fresh or salt water use motor, if salt water use, is it religiously flushed with fresh water soon after returning from boating ?

Just in case install a fresh OEM impeller and micropish with finger the liner housing with toothpaste in circular motion till shinny and smooth to your firngerprint Assuming all water passages are impeccable clean motor will pee much stronger. Will be good to remove the thermostat, brush it off with a hard bristtle toothbrush and vinegar if found in excellent condition or replace for a new one if excessively rusted, salted or a combo of both situations..

Happy Boating​

Yes this is run in saltwater motor is flushed every time after use
I have a brand water pump kit to install and waiting on thermostat to arrive
When boat sits for 2 weeks I lower into bay start motor no peeing in 20 seconds I shutoff hook up hose flushing engine takes about a minute to get water out of pee hole then I can lower boat back down start it then turn off start again and then I have water out pee hole she will run all day long idle or full throttle motor runs great if I stop at a bar for an hour then I have to start motor turn off restart then water out pee hole if I start 1 time overheat alarm comes on
It's like it's vapor locked with back pressure

 

[racerone]

No such thing as vapor lock in your cooling system.

 

[flyingscott]

Is this motor under warranty? It's only 2 yrs old.

 

[Sea Rider]

Wondering if the 2 year old shot impeller is an OEM or aftermarket bad quality one which could account for such lousy state ? After close inspection enlarging the posted pic that impeller is really screwed, an impeller in still good working order should spring open all their vanes once removed from the liner (cup) and this one has all the vanes way hardened and stiff. Better install a complete water pump kit as the cup might also be highly damaged due to shot impeller.

Assume that motor has a rubber water hose for which pees out, is the other end connected to a nipple located on any part of the lower block ?

Happy Boating​

 

[racerone]

Rubber is vulcanized by heat when in a mold.-----The process still carries on ( slowly ) once part is out of the mold.-----Hence the question about how hot this motor gets in sunlight on the hoist !

 

[Sea Rider]

Rubber is vulcanized by heat when in a mold.-----The process still carries on ( slowly ) once part is out of the mold.-----Hence the question about how hot this motor gets in sunlight on the hoist !

If an impeller gets highly screwed while a motor's lower leg sits out of water sitting on a transom, hoist, swim platform on warm days should not be deformed as seen in pic. In this particular case any other non hidden rubber piece would go the same route. Now imagine the extremely high daylight heat found in Arabia, Africa for Yam impellers going that way, no way!! Rubber made impellers will last much less long than elastomers made ones..

Happy Boating​

 

[QBhoy]

Just pulled

That’s your issue. That impeller is finished. All cracked, perished and really poor shape. Get a genuine Yamaha one and do the whole assembly too. All will be well.