Tell-tail on yamaha 300

[Fishtank]

Went out in the new boat yesterday, has a 2013 yamaha 300. Noticed that the tell-tail was extremely weak at first, just a drissle. Engine temp never went over the 3rd bar on the yamaha guage. Stuck a wire up there to see if anything was blocking it, maybe increased a little. Even on the hose at home not much coming out compared to previous engines. Didn't run it with the muffs on. Anybody else experienced this on these engines. Previous owner was meticulous about bringing it in and getting it serviced but didn't know when they changed the impeller just that he always brought it in for service. Was going to change impeller anyways for piece of mind before this problem.

 

[FisherTim]

Went out in the new boat yesterday, has a 2013 yamaha 300. Noticed that the tell-tail was extremely weak at first, just a drissle. Engine temp never went over the 3rd bar on the yamaha guage. Stuck a wire up there to see if anything was blocking it, maybe increased a little. Even on the hose at home not much coming out compared to previous engines. Didn't run it with the muffs on. Anybody else experienced this on these engines. Previous owner was meticulous about bringing it in and getting it serviced but didn't know when they changed the impeller just that he always brought it in for service. Was going to change impeller anyways for piece of mind before this problem.

The Tell Tale is exactly that. It doesn't actually cool the engine, it just serves as a visual indicator that water is getting to the powerhead.

If its really extremely weak, I would take a look at the Fuel cooler in the VST(Vapor Seperator Tank). It's the last thing on the coolant water's path before the tell tale and can get clogged up with salt.

EDIT: upon a little more research, that was true for the 3.3L 200-250 engines, the 4.2L 225-300 have the Rectifier cooler as the last thing before the tell tale.

 

[Fishtank]

Maybe I'll replace the impeller for piece of mind and if the stream is extremely weak still ill dig further. Is the fuel cooler hard to get at?

 

[noluck]

once you drop the leg, clamp a hose onto the water tube going into the powerhead and give it some water from a garden hose, see if it has a stronger flow

 

[Old Fisher]

Maybe I'll replace the impeller for piece of mind and if the stream is extremely weak still ill dig further. Is the fuel cooler hard to get at?

Those motors have minimal telltale when run on hose or muffs. It’s normal. I’m not sure that it’s a good idea to run the motor with garden hose connected but no muffs. I always use the garden hose flush connection and muffs simultaneously when running the motor on the driveway. Then I know for sure that the impellor is getting enough water as well as the powerhead.

 

[ship happens]

Those motors have minimal telltale when run on hose or muffs. It’s normal. I’m not sure that it’s a good idea to run the motor with garden hose connected but no muffs. I always use the garden hose flush connection and muffs simultaneously when running the motor on the driveway. Then I know for sure that the impellor is getting enough water as well as the powerhead.

I think no luck was referring to using straight water pressure from the hose bibb to fill the powerhead to see how the water pressure comes out. Or that's what I understood when I read his post. Think water pressure at your house tap is around 60 psi, which would be more than enough, seeing how water pressure from the impeller would be around 5 psi at idle. Either way would be fine

Compressed air while it's running works really well also. Back flow through the telltale hose

 

[Fishtank]

I think no luck was referring to using straight water pressure from the hose bibb to fill the powerhead to see how the water pressure comes out. Or that's what I understood when I read his post. Think water pressure at your house tap is around 60 psi, which would be more than enough, seeing how water pressure from the impeller would be around 5 psi at idle. Either way would be fine

Compressed air while it's running works really well also. Back flow through the telltale hose

So if the flow is still weak after the impeller change, blast the tell tale hole with compressed air while running?

 

[ship happens]

So if the flow is still weak after the impeller change, blast the tell tale hole with compressed air while running?

If it's a piece of somthing stuck in the passage somewhere the air will blast it out. Yes do it while running .

If it's salt in the vst passage the that would have to get pushed out with a pick

This is why I think water pressure guages are super important thing on a boat

 

[pescador]

When I replaced my old 2003 F225 with a new F250 in 2019 I freaked out the first day. The tell tale on the F225 would cut through a log it was so strong. The new F250 has a weak pee stream like a man with a bad prostate . 300 is the same motor so I suspect its the same.

 

[RiverBoy]

When I replaced my old 2003 F225 with a new F250 in 2019 I freaked out the first day. The tell tale on the F225 would cut through a log it was so strong. The new F250 has a weak pee stream like a man with a bad prostrate . 300 is the same motor so I suspect its the same.

that’s a prostrate thing? great….now i’m freaking out

 

[ship happens]

that’s a prostrate thing? great….now i’m freaking out

Pretty sure the compressed air won't work on that one

 

[brutus]

Pretty sure the compressed air won't work on that one

Lmao, let him try and see

 

[ryanb]

When I replaced my old 2003 F225 with a new F250 in 2019 I freaked out the first day. The tell tale on the F225 would cut through a log it was so strong. The new F250 has a weak pee stream like a man with a bad prostrate . 300 is the same motor so I suspect its the same.

Yes my f250XCA was the same way (same 4.2L power head as f300). Tell tale was never strong from brand new. When on extended trips it would often salt up and get plugged, easily cleared with some 150 pound mono.

 

[DuroBoat]

Yes my f250XCA was the same way (same 4.2L power head as f300). Tell tale was never strong from brand new. When on extended trips it would often salt up and get plugged, easily cleared with some 150 pound mono.

I have a 2021 yammy 300 and was surprised how weak the tell tale was from day one

 

[Fishtank]

I have a 2021 yammy 300 and was surprised how weak the tell tale was from day one

How weak we talking at idle?

 

[DuroBoat]

How weak we talking at idle?

I’ll film it tomorrow and post it.