how long to warm up

[blythebound]

first off, hello to everyone. i've been a lurker for a while but decided to jump in and introduce myself. i recently bought a 2001 ultra stealth with a 496 and berkley pump. i've let it idle for about 5 minutes before heading out but when i do ease into the throtle it almost seems to miss a little. after running it for a while i can jump on it without any hesitation but the first few times i get on it a bit it seems to miss. any suggestions, should i let it warm up longer, should i take it in to get looked at. thanks again. i'm realatively new at jet boats and have learned a ton from reading what you guys write. see you on the river. incase it helps, it's a fuel injected 496

[Yellowboat]

Does it have a t-stat?

[H20MOFO]

Keep in mind, 5 minutes of run time is not likely enough to warm up your oil, accelerating hard with cold oil can spell $$$$$$$$$$.

[RiverDave]

I've always been told let it run until water temp comes up to normal operating temps..

RD

[BadBlown572]

I always try to fire the boat off and let it run for about 5 minutes. I also do not run it hard (3k+ RPM's) until the oil comes up to temp. An easy way to tell this is to watch your oil pressure gauge. When you first fire it off, it will go up to its highest pressure. Oil is extremely thick because it is cold. Once it warms up a little bit, the pressure will start falling off. I just check it at idle. If it falls off, you can tell that the oil has started coming up to temp.



Just a tip. :hmm

[blythebound]

thanks guys. i assume it has a tsat but to be honest i'm not sure. i will let it idle for a while longer and watch the oil pressure. the problem only seems to occur the first few times i give it some gas even though i'm not jumping on it at all. taking it out again saturday so i'll pay more attention

[Flat Broke]

Is it a Mercruiser 496? If so, you could always have the codes read and see if it's really missing. If it's a 496 with closed cooling, it should have a thermostat and as such, the next bit of info would be somewhat useless.

Jet drives can push a lot of water. Because of the constant supply of cold water (in open non-thermostatically controlled systems) it can be hard to gauge when the engine is up to temp because your water temp will read low. With "old school" setups with open cooling and without thermostats, many folks will have to regulate the pressure and flow of incoming water to accomodate the needs of the engine.

The advice given by Danny is a good way to judge oil temp if you don't have a gauge, but depending upon the oil weight you use the fluctuation can be less noticable. It sounds like you just need to give a bit more time to warm up, but if you're sure it's missing (and maybe not just loading up from the idling) you might want to have the codes read next time you have the boat in for service.

Chris