Flushing engine on 242 limited s

[cmiller]

Quick question on flushing the motors with water. Dose it hurt to rev the motor up to 3-4K and leave it there when flushing the motor out? I was reading in the book and it says to run it to a high idle. Not exactly sure what that means. I just bought my first jet boat 3 weeks ago and am still trying to figure everything out. Went to winterize it last night and when running water/antifreeze through, I bumped it up around 3k rpm to warm it up. Might be overthinking it, but was that ok or at all nesassary?

 

[Scottintexas]

glad to have you on board,

You didn't do any damage to your engine. Some members will say you shouldn't use high rpm on the hose, I don't know what exact RPM "high idle" is but I would guess what ever your normal idle is.

Did you run anti-freeze to prevent water from freezing or for corrosion protection ?

Also, If you haven't already go visit our FAQ section for lots of great info and update your profile with your location so we know where you're at!

 

[cmiller]

Thanks for the feedback! Much appreciated! I ran antifreeze through because of freezing. I know a lot of people say no need, but I’d rather be safe than sorry I guess. So when running water through, is it best to just simply leave the boat in neutral and let it be at normal idle?

 

[Scottintexas]

In the future i would tell you to install some flush valves or use clamps to force all the water to the engine instead of loosing alot out of the inlet at the pump

This is a video i made testing how much water back fed to the inlet

 

[cmiller]

? sounds good. One last thing, when I was flushing with water, it was coming out the pissers as it should. However when I started the process with antifreeze, I couldn’t get it to come out the pissers. I was using a small pump And a 5. Gal bucket to do this. Dose there need to be a certain amount of pressure before it will come out the pissers?

 

[Scottintexas]

Dose there need to be a certain amount of pressure before it will come out the pissers?

yes, what the exact amount of pressure is nobody knows but plenty of people who flush at home don't have enough water pressure to activate the indicator lines,

I wouldn't even worry about it until you at least clamped the cooling water inlet hose,

It would be an interesting test to put a bucket underneath the cooling screen at the nozzle and then pour water from a bucket or however you feed antifreeze and see how much comes out there vs. makes it's way into the cooling system, I would guess with just gravity pressure most all the fluid is NOT going into the engine.


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[Scottintexas]

if you haven't see it yet, in our FAQ section there is a video a member made of "how the cooling water flows", it's for mr1 engines but the layout is the same for all our engines and it is definitely worth watching for any Yamaha owner,

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