Jetski dry start

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insanity

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While I was pulling the hub off my car hauler today to check the damage done to the spindle and hub. I hear the tell tail noise of a jetski start up. I stand up to see the owner reving his new jetski with out water hooked up to it. As I start across the parking lot to warn him of the mistake, he kills it jumps in his jeep and tears out of the parking lot.
 

64osby

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Re: Jetski dry start

I see guys starting their jet skis on the trailer all the time when there fresh out of the water. I thought there was something about cleaning the water out of them and that it wouldn't hurt the cooling system.

I've never bothered to ask why they do it.
 

shaneb0422

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Re: Jetski dry start

I see guys starting their jet skis on the trailer all the time when there fresh out of the water. I thought there was something about cleaning the water out of them and that it wouldn't hurt the cooling system.

I've never bothered to ask why they do it.

It is common to flush them after retrieving them. Just a very quick start and rev. It pumps all the excess water from the lake out of them. So they don't drip slowly in say, your garage.
 

insanity

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Re: Jetski dry start

I cant say the last time it was ran, but he did this before going to his favorite spot.
 

arks

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Re: Jetski dry start

I usually 'pre-start' my '97 SeaDoo for 10-15 seconds before launching just to make sure everything's A-OK. Doing so doesn't damage anything, and she'll start instantly when dunked. If it were to run for more than a minute or two out of the water then there's a chance of engine overheat because there'd be no raw water circulating thru the engine.
 

Jeepster04

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Re: Jetski dry start

Its ok to start a jet ski out of the water, at least I know it is a sea-doo. My jet ski(06) has a closed cooling system with a heat exchanger on the bottom of the jet ski. The heat exchanger is called the 'ride plate' and it always in contact with the lake water to cool it. The exhaust sucks up its own water to cool the exhaust and spits it back out. You can hook a hose up to the exhaust when out of the water to cool it but you still wont have anything to cool the engine so you can only run it a short amount of time. Something called the carbon seal will also burn up(it seals the shaft going to the impeller). After we take ours out for the last time of the year I always start it and burp it on the ramp to get all the water out that I can.
 

rajjneef

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Re: Jetski dry start

Good thing you didnt make it to "warn" him of his "mistake". There is nothing wrong with starting a ski out of water for a brief period unlike an I/O.
 

seaboo

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Re: Jetski dry start

Good thing you didnt make it to "warn" him of his "mistake". There is nothing wrong with starting a ski out of water for a brief period unlike an I/O.

Correct, the manuals for both my skis state you can crank and run them (for NO LONGER than 30 seconds without water hooked up).

Just for info the impeller (same purpose as a propeller on a boat) is what intakes and circulates water on a jet ski--this part is stainless steel so no damage results from dry starting.
 

H20Rat

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Re: Jetski dry start

i have yet to see a jet ski that will be damaged by running out of water for a short time. (30 seconds, max of minute if idling)

As others mentioned, no impeller, no water pump. The damage will come from overheating the exhaust, engine, or shaft seals. None of those are issues if done for a short time only.

In fact, it is specifically recommended in the manual to blow out water with a couple short bursts of throttle after loading.

it isn't just jet skis, most jet boats are going to be the same. My current boat has a 2.5l v6 mercury engine, identical to the outboard version, EXCEPT there is no waterpump. There are some holes in the wear ring around the drive impeller that creates a nice high pressure area. Running without water for a short time is not a problem.
 

waterinthefuel

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Re: Jetski dry start

We have a jet ski. This is common practice. A jet ski uses pressurized water from a pickup in the jet output nozzle to inject water into the water jackets for cooling. It does not have a water pump. This is recommended by the manufacturer to rid the ski of excess water. Ours recommends 15 seconds of revving to clear it.

This is not a SHT. This thread should be moved to dockside chat or technical topics. Just because the OP wasn't aware of the correct procedures regarding jet skis doesn't make it stupid.
 

insanity

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Re: Jetski dry start

Thanks for the info I was thinking it was like any other motor and needed water to run safely.
 

seaboo

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Re: Jetski dry start

Thanks for the info I was thinking it was like any other motor and needed water to run safely.

Just fyi, I think It's great you were going to look out for someone and offer advice. Folks here are just explaining the way it works and how it works for information purposes. Until I owned/was around jet skis I thought the same way. I've seen folks do the same with i/o's or outboards at the ramp and no one correct them.

Personally I commend you for being willing to take the time and help someone out.
 

jollymon

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Re: Jetski dry start

Good thing you didnt make it to "warn" him of his "mistake". There is nothing wrong with starting a ski out of water for a brief period unlike an I/O.

Not only is there nothing wrong with it, but I my ski I was told if you are running it on the hose, to dry start it, and not to turn the water on until it was running, and to shut the water off be fore shutting it down.
 

hubbard53

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Re: Jetski dry start

yeah peeps used to give me wry looks all the time when i pulled the jet boat from the water and blew out the intakes and exhaust... :eek:
 

PGFISHER

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Re: Jetski dry start

Not only is there nothing wrong with it, but I my ski I was told if you are running it on the hose, to dry start it, and not to turn the water on until it was running, and to shut the water off be fore shutting it down.

Yours was most likely a 2 stroke and this procedure is to keep from filling the engine with water through the exhaust ports.

Jet skis, wave runners, sea doos and all personal watercraft are o.k. to run for short times without water. We short run them to tune them up, and check for exhaust leaks.
 

Thajeffski

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Re: Jetski dry start

I live on the ocean, so it really does make me laugh when I see people doing this....... only to go home and hook it up to a hose to flush it.

Hello dummy - no need to "blow out" the salt water, if you're just taking it home to flush it anyway.

IMO you really don't need to do this at all. I've owned skis for quite a long time and "blowing it out" at the ramp is a waste of time and gas.
 

thefox1051

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Re: Jetski dry start

I was at the lake this weekend watching an older man show two newbees how to use his newer 2 stroke sea doos i watched him dry start them up and rev them at high rpms. I just thought om my.
 

coolguy147

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Re: Jetski dry start

now dry starting and over revving is totally different. i dont believe you should rev your jetski to very high rpms because of the no load condition?
 

waterinthefuel

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Re: Jetski dry start

now dry starting and over revving is totally different. i dont believe you should rev your jetski to very high rpms because of the no load condition?

That is correct. Most engines, I assume, have rev limiters but no, by revving we don't mean squeeze the throttle to wide open and leave it there. I mean gently squeezing the lever and letting it off rapidly.

And it isn't a waste of gas to do that. Residual water in the exhaust and other systems can cause problems, especially if it is stored like that in cold weather. Lines can freeze and things can crack.
 
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