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Happens when you rinse with the muffs also. First hand experience... Running great now, not that hard to resolve. Dealer told be the engine was done!

Great video boys!!

Great Video, and good that you teaching your kids, so they will be saving some money and doing their own repairs Great video THANK YOU !!!

Asid flush with foot off i would of done pop out thermostats out put caps back on

Great music. I’m pretty sure what you’re saying is what I needed to hear though

Asking for real trouble taking off the heads unless you are a professional

Involved Your Kids in Mechanic's, Good Video

@08:50, use a media blaster, w/pecan or walnut husks ,depending on severity of the head, corrosion, etc.

****PUT THE BOLTS BACK IN PLACE BEFORE CLEANING @ 08:20 time in the video (to prevent thread issues later !

***FYI*** preferred gasket removal tool/s, HARBOR FREIGHT TRIM TOOL KIT, not a aa METAL FLATHEAD screwdriver (@ 05:10 , which tends to severely scar the head or H20 jacket, etc. DUDE, FO REAL .)

$180 is expensive? Have you priced out a new Yamaha 200?

You aren’t supposed to start the engine while hooked to the flush port.

FYI: That isn’t a trim-tab, it’s a zinc that should corrode and be replaced every few years. That additional 7th bolt is what holds the zinc on!

2 words- MURATIC ACID. tape all mating surfaces before applying. Dip in soapy water to neutralize.

You engine vro is running lean on oil which can cause overheating or faulty thermostats

Thanks for the vid!!! I just did both thermostats... and my poppit (PRV) valve. My motor, 2001 250hp ox66 SX250TURZ, also has a "thermosensor". Only ONE, on the STARBOARD side, directly next to the thermostat, I have a thermosensor sticking straight up w/ an electrical connection. Online, yamaha OEM parts lists this as a "thermosensor"... but my manual calls this an "engine cooling water temperature sensor". First off, do you do maintenance on these, cleaning or replacing? And second, what's the purpose? If the thermostats are both measuring the temperature of the water, then what is the thermosensor doing? Any insight is appreciated... thanks.

Just remember, flush the engine for at least 15 minutes with salt away. The thermostats must open to flush best you can. I favour a drum to run the motor, either way is OK.

Hello good day. I did not hear you say if you solved the problem, greetings.

Hola , por favor me puede poner por aquí que torke le diste en la primera vuelta y en la segunda para la tapa de arriba y la del cilindro ? Muchas gracias 🙏

Just did this with my 1998 Yamaha 150 two stroke. Only broke 5 bolts taking off the water jacket. No real biggie. Just put them on a drill press with cobalt bits and retapped to 5/16 standard. Order the poppet valve yesterday, its on the way. Hopefully this fixes my overheating problem as I've already done the usual of replacing the impeller, thermostats etc.

Do you have a picture of the impeller? I’m curious to see what it looked like. I got an overheating alarm the other day on the same motor. I’m thinking about your other video and cleaning out the water jacket. Pretty sure that super dirty. I’m getting a weak stream coming out so it’s either the impeller for the salt buildup in the engine.

did you have to remove the halfmoon lock to remove the water pump plate?

I just went out yesterday and my HPDI 250 over heated when I opened it up but not while at low idle. I thought I saw a bit of smoke coming out the exhaust but thinking back on it, I'm wondering if it was steam. I'm hoping it's the thermostat or the gasket. The entire top end was rebuilt 5 years ago but do to covid it sat for 2 to 3 years. Anyway I am hoping its a simple fix. I appreciate your video, thanks.

Hello. I have same problem with my ox66. I took al 14 bolt out. But now i cant take head out. Its not coming loose. Any idea how should i take head out.

Poppet valve definitely was the overheating issue on my 99 200hp OX66. Was stuck in the open position and would overheat when idling. There was a design issue and Yamaha changed the design to prevent the sticking open.

dude you kick ass! this is awesome very informational. fixed my over heating issues

What up with the music trying to listen but is so distracting.

they charged you 800 fucking dollars?

You work on ox66 a lot or just yours

The main part should have been shown, going back with the water propeller

Hi does your ox66 run rough around 5 to 6 mph ? If so why? Any other speed or idle is perfect

Ese reel daiwa de los antiguos,son buenísimos

I have same boat, same color only motor year is 2003.nice video.thank you

Just love how you said video on how to do water pump and you didn’t show putting the hard part together great video

I just did mine last weekend on the exact same engine. Thank you for this video. It was a great help.

Your video fucken sucks why do you idiots play fucken music when your working and showing people whats wrong fucken stupid thinks for the worst song on earth also

rydlyme marine descaler would have saved you a lot of time and you got lucky you didn't brake some head bolts Yamaha suggest dipping the bolts in two cycle oil before reinstalling

Would all this be the same on a 2004 200hp salt water series II

Just an FYI ( my $.02) The "heads" that you referred to while explaining to your son, are the CYLINDERS. You had already removed the HEAD. This operation is VERY critical and LOTS can go wrong, ESPECIALLY broken bolts. It doesn't matter, really, what you say to US when doing an instructional vid but it DOES matter when instructing your child or a friend who looks to you for knowledge or advice. Those engines are now PUSHING $20,000 AND UP NEW, so ANYTHING we can do to avoid going to the stealership is good for us but being meticulous about how we do it is the key. I don't fault anyone for trying to repair their own stuff and when/if they have to bring it to me to fix a flub, I tell or show them how to do it correctly. where some mechanics seem to revel in teaching them a lesson for DARING to try to fix their own stuff. Some of the other details are listed in the comments below so please don't take it personally. Some of us learn by doing and then others are lucky enough to learn from doers, so it's good that you take the time to show people what to expect. ....

They're not studs they're bolts!

Please spare us the Katy Perry

I would change the poppet valve

so I just rebuilt my 2.6L OX66 , same block as yours and it runs hot and will overheat over 4000 rpm , I have 80 hours on it so Its mechanicaly correct , I did paint the water jackets on the heads , im wondering if I put too many layer of paint on it . new water pump , thermostats and the updated pressure relief valve

Love this set up...by far the best. Did you run the wire from one post all the way around to the other end?

Throw the heads in a dishwasher

Can’t hear a thing other than music

Have you ran the boat since doing this? I was told the shaft should go in all the way without tightening bolts

Where do I order these gaskets

Looks pretty cool. 👍⚾️⚾️⚾️

2 stroke motors have water passages around the combustion chamber, cylinder head, exhaust covers and lower crankcase areas which sould be cleaned as well to factory delivered conditions. I know huge work removing the entire crankcase to access such parts. Once cleaned will need to install new gaskets on those mentioned parts right after all the mating surfaces has been cleaned to an immaculate state. Rydlyme, Salt Away only works well removing salt layers, but not heavy solidified stone rock crusts clogging the water passages in which these products won't recirculate through to do their homework right.