I have a 2018 SHO 250 with 10 hours. It is now awaiting a new powerhead. Since my issue, ive been doing a little research, and it seems like a lot of these motors are having issues around that 200 hour mark. Is anyone getting a large amount of hours without any issues? I certainly don't want to end up having to do this again at another 200 hours.
275 hrs on my 2017 200 SHO.. No problems so far.. But, every time I get on this forum, I have a panic attack...I’m afraid the next time I start it will be last time it runs on the original power head.
Sorry about your misfortune. Hopefully it gets resolved quickly.
Dude it is scary for real! I am anal about maintenance, warm ups, cool downs and have never had a warning horn of any kind. I however have had cracked heads on my 2014 250 SHO with 200 hours that was replaced with a new powerhead. I am currently waiting on my Yamaha dealer to give me the news on my replacement powerhead (191 hours since replaced first time). It is leaking crankcase oil in the same place as last time so my guess its not good! To beat it all parts for these motors are very limited last couple years. I told Yamaha and my dealer if I cant get this engine fixed before April I am going to a competitor!Originally Posted by Beetlespinner
So I would say around 200 hours is about what to expect! When you pay $20,000 for an engine it shouldn't be this way. I have had multiple outboards of other brands and have never had a powerhead failure or heads cracking! Actually never a major component failure at all... Things to consider going forward.
I've seen several come through the shop with over 700 hours. I will tell you that I've only replaced SHO power heads on bass boats. Never personally seen one fail on pontoon or work boat.
I too am concerned that there is an inherent flaw in the SHO design / materials used. There are just too many of these engines going pop after a few hundred hours. Perhaps it is much more of a problem in the bass boat market than pontoons but a SHO is marketed and sold as the premier reliable bass boat engine by Yamaha. I have been onto a suspicion for some time. I have no proof of this but I'm going to lay it out. I may be totally off base but here is my take on it. The SHO has plasma hardened cylinder walls. As far as I know it was the first and maybe still the only outboard to have this technology. I wonder if the combination of the very hard cylinder walls compared to the piston rings being used along with perhaps extra tight tolerances are to blame. Another red flag for me and something I think impacts all outboards but maybe the SHO design even more. That factor is that our engines use water for cooling pulled from the body of water we are in and it is an open loop system. That is the key word --- OPEN loop. I understand that a SHO even run WOT for 20 minutes hits only 142 - 145 degree F. That is too low to allow oils to do their job in my opinion. Now combine that with the fact that the temperature can vary a lot and that may be why we are having so much trouble. I understand from my research that Mercury designed their new 4 strokes to run as high as 240 to even 250 degrees! I personally think this may be too much, after all the optimal oil temperature for an automotive engine is around 190 - 200 degrees. 190 - 200 is hot enough to allow the oil to do its job and hot enough to burn off moisture in the crankcase. Auto engines lasts thousands of hours due in large part to their CLOSED loop water cooling set up. Other outboards, even Yamaha non SHO engines just don't seem to have the engine blowing problems so I think with the SHO it is a combination of design, materials used, and manufacturing tolerances that all add up to the perfect storm of being damaged more by low operating temperatures caused by the open loop cooling. A radiator and thermostat system allows the engine to slowly get to the optimum operating temperature for the oil and metals used in the engine to deliver performance and long life. In my opinion and I've posted this before now. We need an outboard with a small closed loop cooling system. I don't know how you would do that and not have a big weight penalty but I believe such an outboard would live longer. I know some will ask, then explain why there isn't the problems with SHO's on non bass boat applications. How many SHO engines are really used on pontoons? Those that are are started and then cruising around so not as much temperature swings. I know the Yamaha F series is know as bulletproof but it is a different design which evidently is more forgiving of the wide operating temperatures that outboards see. I believe a closed loop cooling system would benefit all outboard designs and it would appear that Mercury is trying to get their 4 stroke engine hot enough to at least take care of the moisture condensation problem and once a Merc is up to 240 or so it won't cool off so quickly as an engine that at it's hottest is 100 degrees cooler (our SHOS!). Thanks for reading and remember, when someone comes out with an outboard with a super light weight closed loop cooling system --- you saw it here first:-)
Last edited by ChooChooSnakeMan; 02-19-2021 at 11:53 AM.
Mine is a 2018 and lasted 204 hours, new powerhead due to two pinholes in the block, I am very meticulous about maintenance as well.
I'm the original poster for this thread, and I forgot to mention, that I too have been very meticulous with my maintenance schedule, and always try to warm the engine and cool the engine before and after running it. Also, the shop that is doing the repair said that the engine looked like new inside, BUT.....here we are.
SHO block temps get well over 200°F during operation. What you see on digital data on graph or anything measured off of Tstat housing is not block temps. There are lots of pontoons out there with SHO and many more offshore boats with the same base engine long block as SHO. The offshore guys don't have near the problems with powerhead failures. This proves that the big problem is with the way these engines are being used on bass boats. In my opinion it is the lack of proper warm-up and lack of extended running at those higher temps. That is the main thing that I noticed on majority of the ones that I replaced. I am not including the ones with cracked heads or any other MFG flaw. Obviously those shouldn't be included in trying to find out what is causing the others to fail. All this is just my opinion.
My 2011 popped at 130 then replaced in 2014 and I can it till 290 with no issues. My 2019 has 70 hrs on so far and has been flawless.
My 2018 has over 300 hours. Only problem was right after getting the boat/motor the lift pump went out, replaced and still going. I rarely go WOT and my average speed is probably 40-45. I also believe the more hours you put on these any any outboard the longer they will last. My brother had a 2011 200 and it went down at around 122 hours and 9 years with water in the crank case. Yamaha replaced the power head out of warranty. He recently traded that boat in for a new ZXR20. I believe that the SHO is no better or worse than any other brand which at this point is pretty much Mercury. Check out that board and you will find many issues over there as well.
2021 Skeeter ZX225
2021 Yamaha SHO 225 VF225LA
MY 2011 SHO replaced powerhead at 187 hours, now has 850 hours and runs like a raped ape
Butch Derickson
2011 Z521 w/250 hp SHO
Traverse City, Michigan
I have a 2012 200 sho with 563 hours on it. About a month ago my son and took off from the landing after we let the motor warm up. I ran it on step for about 2 miles. We fished for 2 hours and when I started it up it missed real bad at idle. I turned around and it looked like we were fogging for mosquitoes. Lasted for 4-6 seconds. We idled back in. I changed oil and got about 2 tablespoons of milky oil. The rest of the oil looked ok. Also had milky oil on the filler cap and filler tube. I have it at the dealer. Just waiting for them to find time to look at it. This is the first problem I’ve had with it.
Milky oil on the filler cap is from condensation. This happens when the motor isn't brought up to operating temperature long enough to burn it off.
I assume everyone is talking about the V6 SHOs? How about the 4 cylinder? I'm just hitting 100 hours on my 175.
I think my problem and others with the 200, 225 and 250 SHO with cylinder heads cracking is due to a casting flaw. Or just a bad design not letting water completely drain.
This from what I can tell is happening when ambient outside temperatures fall below freezing. Both times I have had heads crack is when this happens. Regardless of precations and taking every measure to make sure water has drained from the engine. I always keep engine trimmed down level to help with draining when parked as well. I have noticed on this board many others seem to have head cracking problems everytime nights begin to dip below freezing! The facts point to water not being drained from the heads completely. Obviously this is just my take on cylinder heads cracking not powerhead failures. That is a different beast all together.
I've had my SHO for 9 years.....garage kept. I leave the motor down and hopefully drain completely. Just out of curiosity I broke open the flush port and watched it drain. Close to a 1/4 cup of water or more came out of the port....kinda shocked me since the engine had been left down overnight. Could this be part of the problem with heads cracking in colder/freezing weather. I do not know the answer, but just an observation on my part. Lots of entrained water came out of that flush port. Any thoughts are welcome.
Freezing water is definetly not an issue for me here in S. Central FL.
Reading all this about the sho starting to have some hpdi thoughts. The merc is having it’s share too. Scared to spend 20 grand on an upgrade
The SHO models and the Offshore models use essentially the same block. Offshore owners are getting multiple hundreds if not multiple thousands of hours.
One might believe that any difference in service life is due to operational usage.
Offshore owners start up and usually have to boat to a point where they can get on plane. Motor is fully warmed up. They typically come up on power relatively slowly. Using relatively low pitched propellers. Then cruise at generally 3500 ~ 4500 RPM.
Bass boat maniacs, I mean owners, fire up and are ready to rock and roll. They stomp down on the gas pedal and are going WOT in a nanosecond. Using a relatively high pitched propeller. They run balls to the walls every where.
Just a wild eyed guess on my part.
Firm believer they hold water and crack after a freeze. I’m getting mine repaired at this very moment and I’ll take every precaution possible to keep it protected in freezing weather from now on. Christmas lights, space heater, blankets....whatever it takes.
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