• Welcome to Jetboaters.net!

    We are delighted you have found your way to the best Jet Boaters Forum on the internet! Please consider Signing Up so that you can enjoy all the features and offers on the forum. We have members with boats from all the major manufacturers including Yamaha, Seadoo, Scarab and Chaparral. We don't email you SPAM, and the site is totally non-commercial. So what's to lose? IT IS FREE!

    Membership allows you to ask questions (no matter how mundane), meet up with other jet boaters, see full images (not just thumbnails), browse the member map and qualifies you for members only discounts offered by vendors who run specials for our members only! (It also gets rid of this banner!)

    free hit counter

Coolant water steaming hot

Buckeye Boater

Jet Boat Addict
Messages
111
Reaction score
81
Points
102
Boat Make
Yamaha
Year
2017
Boat Model
X
Boat Length
21
so I finally got around to putting a SVHO intercooler in my AR192. After double checking everything I took her out for a spin. I was out. Maybe 15 minutes with lots of WOT in that time. I brought it in and the engine cooling line was pissing out water so hot I could see the steam coming off of it.

I don't normally check the temp of the outlet water so I don't know if this is abnormal or even new. I don't have any warning lights or anything indicating it's running hot.

Any suggestions on what to check? Just normal?

Thanks
 

Seadeals

Jetboaters Admiral
Messages
1,273
Reaction score
1,498
Points
262
Location
Greenville, South Carolina
Boat Make
Yamaha
Year
2006
Boat Model
SX
Boat Length
21
The water's job is to extract all that heat you built up in the engine running WOT, so I guess it could be fairly warm (steam in the right weather conditions-dew point). Now that you mention it, I also have never felt the "pee" water streams for temp. That sounds like a level of intimacy with my boat that may cross a line.

I wonder how long it takes a molecule of H2O to make it through the cooling system. If it does heat up that much, it sounds like Yamaha actually might have missed a golden opportunity for another warning sticker!

BTW on Father's Day my 8 year-old finally noticed and read the swim platform sticker and started asking questions. I left it there for adult guests to enjoy. Man, they are growing up fast. Needless to say, my wife deferred all of the questioning to me.
 

Murf'n'surf

Jetboaters Fleet Admiral
Staff member
Administrator
Messages
7,086
Reaction score
6,037
Points
527
Location
Naples Florida
Boat Make
Yamaha
Year
2005
Boat Model
SX
Boat Length
23
Seems or steams normal to me. Ive been nearly burned by some water exiting the exhaust port above the nozzles.
 

swatski

Jetboaters Fleet Admiral 1*
Messages
12,806
Reaction score
18,567
Points
822
Location
North Caldwell, NJ
Boat Make
Yamaha
Year
2016
Boat Model
AR
Boat Length
24
If you do not have a separate intake for the new IC, one potential issue with those setups is starving the engine cooling at the expense of water flow to the new IC. I would re-read the 192 mods and other threads if you worry about it, this has come up before. I remember there was some discussion of that, I'll try to look it up later.
But as long as you have water flowing and no codes thrown - I wouldn't worry too much.

--
 

haknslash

Jetboaters Fleet Admiral
Messages
7,557
Reaction score
8,950
Points
557
Location
Lake Martin, AL
Boat Make
Moomba
Year
2019
Boat Model
Other
Boat Length
23
Like I mentioned on the FB post I'd say normal especially after some WOT runs. I've seen steam come out of mine even when flushing. As long as you're not throwing any over temps alarms you're good to go and enjoy the boat.
 

d_coyne1984

Jetboaters Admiral
Messages
1,015
Reaction score
965
Points
252
Location
Chanhassen, MN
Boat Make
Other
Year
2020
Boat Model
Other
Boat Length
21
I'll try tobchrck the temperature of mine tomorrow after some wakeboarding runs. I have no idea what it was before the IC change as a baseline though.
 

d_coyne1984

Jetboaters Admiral
Messages
1,015
Reaction score
965
Points
252
Location
Chanhassen, MN
Boat Make
Other
Year
2020
Boat Model
Other
Boat Length
21
I didn't get a thermometer on mine today, but it was quite hot against my hand. I also noticed at one point there was no water coming from the engine pissed. I never got any alarms, but I think @swatski is right. I am thinking I might combine the two IC exhaust lines to add some pressure back into the system, at least until I feel up to drilling more holes in the boat.
 

d_coyne1984

Jetboaters Admiral
Messages
1,015
Reaction score
965
Points
252
Location
Chanhassen, MN
Boat Make
Other
Year
2020
Boat Model
Other
Boat Length
21
I didn't get a thermometer on the engine exhaust water today, but it was pretty hot. Almost to hot to keep my hand on it for long. At one point I noticed there was no water exiting the engine pisser. There were no alarms, but I think @swatski is right. I may try to combine the two IC exhaust outputs to one line to add some pressure back into the system, at least until I get the courage to drill more holes in the boat.
 

haknslash

Jetboaters Fleet Admiral
Messages
7,557
Reaction score
8,950
Points
557
Location
Lake Martin, AL
Boat Make
Moomba
Year
2019
Boat Model
Other
Boat Length
23
You don't have to have a dedicated IC water inlet line with the intercooler upgrade. The SVHO doesn't come with one stock but you can add it if you wish. Just be careful adding too many cooling flow mods because you can get gas in oil according to the greenhulk forum threads.
 
Last edited:

Midnight2V

Jet Boat Junkie
Messages
140
Reaction score
88
Points
127
Location
Houston Area
Boat Make
Yamaha
Year
2022
Boat Model
AR
Boat Length
25
For those that are interested, here are just a couple of reasons why too much cooling, especially in a supercharged engine that is tuned for running in a specific temperature range, can be a very bad thing -

Having built a supercharged engine or two from scratch, I imagine that Yamaha built a little more gap into the rings on these engines than a naturally aspirated engine would see. They definitely used a significantly lower static cylinder compression. That means that under the right conditions - prior to reaching normal running temperature - more cylinder gasses (not just fuel, water vapor also) will leak past the rings, and into the crank case, eventually ending up in the oil pan. That's OK....once the system does reach normal operating conditions, the engine oil should be plenty hot enough to vaporize off any fuel or water that does make it into the oil. Also once the engine gets to normal operating temperature, the cylinder leaking should be reduced to an absolute minimum. If the engine does not get hot enough to vaporize contaminants out of the system, cylinder leaking will continue, they will mix with the oil and a whole host of problems can occur.

Installing extra cooling ports on an otherwise stock engine that bypass the thermostat housing (or removing the thermostat altogether) will create a temperature stratification across the engine. That means that there will be some points that are significantly hotter than others. That means you get uneven heat expansion across sealing surfaces, unbalanced internal stresses on lots of parts like the block, the cylinder head, and who knows what else. Sealing surface problems can cause a blown head gasket, significantly different temperatures cylinder to cylinder can cause either a lean or a rich condition. Lean condition can cause pre-detonation (uncontrolled auto-ignition of your gasoline/air mixture) and catastrophic engine failure. Rich conditions will cause more gas in the oil and magnify the problems with contaminants in the oil system.

Something else to consider is that if the cylinder doesn't seal properly you can get oil in the combustion chamber. The common thing is that you foul a plug, especially if the cylinder was already rich to begin with. IF, however, the cylinder was lean to begin with and you now have 40 octane motor oil in the cylinder with 87-93 gasoline, you increase your chances of pre-detonation significantly.
 
Top