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  1. #41
    Hurricane1000's Avatar
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    Dean at Dean's Team
    DOES NOT RECCOMEND
    the Thermostat delete!


  2. #42

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    Quote Originally Posted by Hurricane1000 View Post
    Dean at Dean's Team
    DOES NOT RECCOMEND
    the Thermostat delete!
    Quote Originally Posted by mwhc View Post
    Unless you have a standalone and can dial in (run your ski) perfect AFR as lean as possible you will get GIO. You could possibly restrict water flow to the oil cooler but been there done that. Works decent but I'm full standalone.

    Engine just runs too cool with that restrictor only.

    I read both of your replies and I am one for taking good advice, so my idea went out the door. Well then.... out comes the thermostat delete kit that I thought would work. Thanks to you both.
    Will work on it again in the am.

    Take Care Harricane and mwch
    C J
    Last edited by cjk6119; 02-28-2020 at 11:57 PM.

  3. #43

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    With some here restricting the water flow to the oil cooler and some capping off the water flow to the intercooler to run a dedicated line to the intercooler. All this added pressure and volume, could this all be creating a high pressure blockage at the thermostat.? When the engine is backed off of wot and the pressure drops from the jet pump, the stat is able to open up off it`s seat and then an inrush of cold water then shocks the head that is been just heat soaked? Is that why we see so many heads cracking on the exhaust side of the heads? Thermal shock of the metal would explain why skis are having problems mainly in cold water areas.

    The thermostat is in a condition called hunting while under wot and not staying open.

    From SuperStreet Online Magazine

    Written by David Pratte

    Where the performance of a thermostat is less obvious is with respect to its flow characteristics and how this impacts overall engine cooling. Hunting, meaning dramatic changes in temperature, is a common problem with lower-quality thermostats because they allow too much flow when wide open. In a worst-case scenario, hunting can result in a cracked cylinder head from being exposed to such dramatic changes in temperatures, and at the very least it causes a significant reduction in the efficiency of the cooling of the engine.



    Take Care
    CJ


    Last edited by cjk6119; 02-29-2020 at 10:34 AM.

  4. #44
    speeder's Avatar
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    Quote Originally Posted by speeder View Post
    Our riding group in canada has 4 2014 to 2016 fx svho skis. 3 of them had head cracks. the 4th one is in the dealer now for a diagnosis of water in oil which could be the 4th head cracked. we ride a lot in the fraser river around the vancouver area.
    looks like Yamaha is replacing short block and head for the 4th ski (completely stock and was the only ski with warranty). And a new friend with a 2014 fx svho now also has water in oil and we are pressure testing the head in the next few days. what the hell is going on?

    one odd thing is that we don't think the dealer actually pressure tested the head, and did not say that it was a cracked head. could they be trying to hide something by not actually testing the head and just replacing it? what if it is really a widespread problem, and by not saying to the customer, "we tested the head and it is cracked", they've saved themselves a big headache.

  5. #45
    speeder's Avatar
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    ok. so some like data, so I put a couple of temperature sensors on the engine and watched the temps. i put one on the front of the head, and one on the thermostat housing. My ski is stage 1 modded 8500 rpm running 123 km/h (but I have keel guard which slows it down about 5 or so km/h). all stock cooling.

    before start : engine is at 22C (71F), water temp is 7C (45F) (DAMN THAT"S COLD)

    cold start/warm up/ no wake mode:
    thermostat housing gets up to around 44 (111F) then steadies there , front of engine warms up very slowly. after 10 minutes of no wake mode only at 37 (98.6)

    2000 rpm : thermostat housing steadies around 40 (104F), front of engine keeps climbing very slowly, after another 10 minutes is at 44 (111 F) and rising

    4000 rpm : takes another 5 minutes for engine to get to 55 (131)

    GIVE IT : thermostat housing remains steady around 39 (102F), front of engine rises more quickly then steadies around 78 (172F)

    warm down/idle : thermostat housing rises up to steady around 49 (120F), front of engine takes about 17 minutes to decrease to the same 49 (120F).

    ski off/restart : after about 2 hours of sitting around, front of engine has cooled to about 37 (98.6) then climbs slowly.

    going out today to get more data. probably do a hot run then shut down without warm down to see if and how much the engine temp rises...one time shouldn't hurt ( I hope). and also a quick stop and restart.
    Last edited by speeder; 05-01-2020 at 12:14 PM.

  6. #46
    Click avatar for tech links/info K447's Avatar
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    Quote Originally Posted by speeder View Post
    ... the thermostat housing. My ski is stage 1 modded 8500 rpm ...

    ...
    2000 rpm : thermostat housing steadies around 40 (104F) ...
    Is the thermostat stock?
    Cooling system stock or modified?

  7. #47
    speeder's Avatar
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    Quote Originally Posted by speeder View Post
    My ski is stage 1 modded 8500 rpm running 123 km/h (but I have keel guard which slows it down about 5 or so km/h). all stock cooling.
    as above.

  8. #48

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    I have a temperature probe about mounted in the water exit line 3" down that goes out the engine right past the thermostat . on a normal day with 80* lake water the exit water temps usually range from 121 F to 126 F if I run it hard 7000 to 8500 rpms the exit water temps go up to about 135*f to 140 f * I have never see over 140*f ever.

  9. #49
    305coco's Avatar
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    I may be part of this pandemic as I just got water in my oil, I changed the oil 6 times till it was clean then cruised around the lake under 5500 rpms and no water in oil, did a couple wot pulls and got water in the oil instantly, so if the head IS cracked it's letting water in the oil under high load, pressure/heat.. ski runs perfect.

    just pressure tested intercooler to 40 psi and no leaks, so gunna start tearing down to pressure test the head..

    09 fzr, 330 hours, 18 psi wheel.

    the water line that fed the intercooler from factory is routed into where the anode was, feeding the engine more water and the intercooler has it's own dedicated line.

    can the engine have to much water pressure??

  10. #50
    Quote Originally Posted by 305coco View Post
    I may be part of this pandemic as I just got water in my oil, I changed the oil 6 times till it was clean then cruised around the lake under 5500 rpms and no water in oil, did a couple wot pulls and got water in the oil instantly, so if the head IS cracked it's letting water in the oil under high load, pressure/heat.. ski runs perfect.

    just pressure tested intercooler to 40 psi and no leaks, so gunna start tearing down to pressure test the head..

    09 fzr, 330 hours, 18 psi wheel.

    the water line that fed the intercooler from factory is routed into where the anode was, feeding the engine more water and the intercooler has it's own dedicated line.

    can the engine have to much water pressure??
    Your head is cracked it's not water pressure. They crack on stock skis. My first head went about the same hours as yours and still ran flawlessly with 13qrts of water/oil mix hahahaha

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