See full version: Yamaha 4 stroke f150 not peeing
Also, check the thermostat. It could be stuck or salt buildup on the thermostat housing. Some people have done a vinegar flush by filling a trash can and removed a lot of corrosion/blockage using that method. You can also use Salt-Away or Simple Green instead of vinegar for same process to unclog the holes. Make sure you do a fresh water flush afterwards.
Did you change anything in your hose setup like the hose itself? I've seen it where if you use a different hose (ie one of the expandable hoses) or a longer hose, you will not get as much pressure and volume into the inlet. Water did not flow out in that case. Just make sure you are not running the engine with just the hose connection. here
That was one of the first things I did. more
Did you change anything in your hose setup like the hose itself? I've seen it where if you use a different hose (ie one of the expandable hoses) or a longer hose, you will not get as much pressure and volume into the inlet. Water did not flow out in that case. Just make sure you are not running the engine with just the hose connection. [links]
If its peeing fine in water at ramp, most likely low water pressure when back flushing on trailer (motor tilted down not running).
Also, check the thermostat. It could be stuck or salt buildup on the thermostat housing. Some people have done a vinegar flush by filling a trash can and removed a lot of corrosion/blockage using that method. You can also use Salt-Away or Simple Green instead of vinegar for same process to unclog the holes. Make sure you do a fresh water flush afterwards. [links]
So, I may have taken a bit of a diagnostic leap. but, I figured that I had a pump issue.
Hi: I seem to have a similar problem. I have my boat is a 2007 Wellcraft 180 with 115 Yamaha. It was sitting for about two months since last launch in October. I just winterized it yesterday in 35F degree weather. I started up after the oil change with the lower unit submerged in a big rubbermaid container. No peeing. I connected the garden hose to it and got a steady stream. I read somewhere that there could be a thermostat which could prevent water from peeing if it's not warmed up. Is this true that yamaha outboards have thermostats? [links]
Removed the lower-unit and checked the impeller but it looks brand new (no visible defects, at least).
I moor my boat, so flush after every use with Salt Away through the flushing port. Ear muffs are not an option for me, although I doubt I would use them. more
IMO best to run the motor on the muffs because you need to get it hot enough (manual says 5 minutes) to open the thermostats. yeah, theres a t-stat bypass but they're tiny and thats not what they're designed for. they're to let the water drain out of the head after the motor shuts off. more
you can either flush the motor while running it on the muffs OR flush the motor while NOT RUNNING through the port fitting. if you run the motor while on the port, you'll burn up the impeller from running it dry.
Simply use the flushing port that was designed and engineered for that purpose and quit over thinking it.Really not all that scientific.
Have you tried the hose flush port or just running on muffs or in the water itself?
Finally got a call back from my dealer in Coos Bay. He thinks an internal failure.
Will get it looked at next Friday (5th of June) & I will post the results so we all know.
Thanks again for the thoughts. [links]
Thanks guys, I have tried a pc of 80 lb mono, with no results.
These engine ONLY get used in salt water, but I am anal about flushing with Saltaway.
I do live where all kinds of bugs hide in holes, haven't found one. [links]
Here is my report as promised. I hope it helps.
The dealer took the lower unit off & the water pump housing had a blockage where it tappers out to the .50 dia. (approx.) passage hole (looking down on the impeller housing). The housing material appeared to be melted, but the melted material was very thin & only over the hole. The stainless insert had no discoloration, nor did the plastic housing. Dang, I should have taken a photo.
We then dropped the right engine L/U and found it to be OK. Interestingly the wear patterns of the impellers onto the bottom of the stainless inserts were different. In the good pump housing the pattern was consistent, in the housing that would not pee, the pattern was very wide near the intake port. The dealer agreed to warranty the housing & impeller, due to no discoloration on the stainless insert nor the plastic housing.