Engine Damage due to Cold Water

[fishfordollars]

With all the colder water temps down south due to the recent cold spell I though everyone needs to think how they operate an engine.

Buddy brought his 2008 Basscat/225 Optimax by the house yesterday with a hole through the side of the block.

Never had a problem with it and the only thing we can figure is that it cold seized on him. He failed to warm it up before he punched it up to WOT, ran a 1/2 mile and it came apart.

The Optimax/DFI engines with close piston to cylinder wall clearances need to be warmed up (3-4 minutes) and then ease the rpms up to allow the piston and the cylinder wall to build internal temperature equally. Cylinder wall clearance on the 200/225 Optimax runs about .0055. When you fail to warm correctly the cylinder wall will not warm and expand the same as the piston due to the amount of cold water circulating through the block. The piston will expand faster causing it to seize against the cylinder wall. If this happens it will just rip the wrist pin out of the piston and then tear a hole in the side of the block.

So make sure your thermostats are working properly and give those engines plenty of warm up time.

Jack

[Catt]

Operator error will do em in every time

[Jig Man]

That was the first and most important thing the tech told me.  "No matter what the temp is, let that Opti warm up to at least 120° before you leave the no wake zone."  It has worked going on 8 years now.

[fishfordollars]

That was the first and most important thing the tech told me. "No matter what the temp is, let that Opti warm up to at least 120° before you leave the no wake zone." It has worked going on 8 years now.

Thanks jig man. I meant to put the opertating temperature in my post. Very important. Going in the garage now to remove the powerhead. Glad it was not mine.

[I Love BassResource]

My tech told me 115 before WOT.  Is 120 the norm or 115?

Just 5 degrees I know, but that would be a d**n expensive 5 degrees should it fail..

[fishfordollars]

My tech told me 115 before WOT. Is 120 the norm or 115?

Just 5 degrees I know, but that would be a d**n expensive 5 degrees should it fail..

115* is fine. you just don't want to run them before the thermostants open and allow the block to heat equally with the internal parts(Pistons).

[Catt]

My tech told me 115 before WOT. Is 120 the norm or 115?

Just 5 degrees I know, but that would be a d**n expensive 5 degrees should it fail..

115* is fine. you just don't want to run them before the thermostants open and allow the block to heat equally with the internal parts(Pistons).

Take it from a guy who holds a few NHRA titles

[fishfordollars]

My tech told me 115 before WOT. Is 120 the norm or 115?

Just 5 degrees I know, but that would be a d**n expensive 5 degrees should it fail..

115* is fine. you just don't want to run them before the thermostants open and allow the block to heat equally with the internal parts(Pistons).

Take it from a guy who holds a few NHRA titles

Thanks Catt, but that was a car not a boat.

[Catt]

Are they not both internal combustion engines?

[fishfordollars]

Yep, as usual you are spot on. LOL.

[senile1]

Thanks for the heads up, Jack. What a bummer for your buddy.

[Glenn]

Yamaha has been advocating warming up the engine 3-4 mins before bolting down the lake ever since the HPDI's came onto the market.  It's so easy to make this a part of your routine, that I don't even realize I do this now.

[Mr Jenkins]

Who buys a Yamaha though Glenn?

[SoFlaBassAddict]

Operator error will do em in every time

Winner winner chicken dinner..

I let my engine warm up every time I launch no matter what. I always figured it was a common sense kind of thing. Mind you, I have an older engine on my boat and I'm not sure how the newer motors work. I would assume the same holds true though, warm it up before jumping all over the throttle.

[5bass]

If you're waiting for the thermostats to open, you should find out what degree thermostats you have. My 250 Merc EFI has 125 deg.

[Way2slow]

Actually, you're up against two elements that gets the engine, not just the tight clearances a very cold engine has.  How many times have you headed off down the lake on a cool crisp morning and think, D*** this thing is running good?  Kinda like it's making all kinds of extra HP, that's because it is.

Two stroke engines, when properly tunned run very high egt's, meaning the pistons are running close to to the melting point of the aluminum.  Cold dense air actually leans the motor out more, and even if it has an intake air temp sensor, it may not fully compensate for a cold motor.  A leaner mixture means even higher egt's, which means even more piston expansion.  Blasting off from the ramp at WOT on a cold engine, the piston can very easily weld itself to the cylinder.  When this happens, a whole lot of internal parts can suddenly become external parts.  Even on carburated motors, a slightly dirty main jet can ruin your day on cold crisp mornings.

 

[Catt]

Kind of reminds me of two stroke dirt bikes; I could tell when an engine was about to blow because it would get a burst of power especially on top end.

[fishfordollars]

Kinda like the calm before the storm. Our old drag car engines would really pick up right before they came apart.

Two things to do to keep everything together:

Keep it serviced and tuned

Warm those puppies up before you hammer down

[fishfordollars]

A common practice in this area is to remove the center of the thermostats during the warmer months. Although it will make the engines pee like a race horse, I don't do it or recommend it. Checking or replacing the thermostats should become a standard procedure when servicing the motor. They can go bad just like the ones on an auto engine.

Engine temperature can/will control the fuel mixture. It can and will cause it to lean, so keep those thermostats clean and up to date.