Yamaha waverunner FX140 WR1000AC runs hot

I took out my ski yesterday in kbay on the way out high temp light and beeper came on waited went slow same thing but took longer

I thought maybe thermostat but tested it opened ok now I'm thinking some trash in inlet line to engine, since no water from pee hole on left

Did this once a year ago then cleared up

I'm thinking the hole or hose from impeller to engine stopped up

Last night flushed a few if the hoses and no blockage but the supply line super hard to get to I think either hole is blocked or hose down there

On the water hose running no water from weep hole on left and

I did run it a while last week no overheat on water hose in yard about 15 minutes

Putting thermostat back clean the housing was corroded a little but don't think it was problem

South seas didn't stock it anyway

Well last night I put the thermostat back in and hooked it up to the hoses and ran it on the water hose

After about 15 minutes it ran hot again, otherwise the ski runs fine maybe a little rough idle otherwise is smooth running

Temperature comes up slowly so it could be circulation

I checked it with an infra red thermometer and the head came up from 120 to 175 degrees while on the hose

I did check the inlet hose it's clear and the other return hoses I back flushed

Looking on the forums they say could be:

 

bad water temperature sensor (exhaust or engine block)

blocked jet pump intake (not on hose)

blocked passages inside of engine

blocked hoses

sand inside around cylinder coolant jackets

blocked exhaust

or something worse- mechanical

Cracked jet pump housing or cone spun 

head gasket /crack head or other

I would think if I had a head gasket bad it would be running hot quickly,and maybe missing steam coming out exhaust so I doubt that

 I have not taken out the plugs but it is possible that compression is going into the exhaust but I don't think so

I'm debating getting a newer ski anyway, although will still have to fix this one, and I don't really use it allot either

My friend has a 2006 Kawasaki 200 LX but I like Yamaha s better

I can take off the pressure regulator on side of block

 make sure that there is good water flow coming to all of the parts maybe take off the muffler first

see if it's blocked

I did "search the forums" some for some answers and did learn a few things but still have not found the problem.(yet)

We took out the ski the other day about 5 minutes from the ramp the high temperature alarm came on and the beeper

went into limp mode. Let it cool and tried a few more times same thing, then idled back to the boat ramp.

The ski did this one other time last year and then "it went away".

Thanks John for the suggestion to back flush it good idea. I pushed water back into the block side of thermostat hose other night.

I did take the thermostat off when we got home and it tested ok, cleaned the housing and put it back on after 15 minutes running on the hose it ran hot again. I then got my infrared thermometer out and checked the head temp while running on hose slowly came up from 140 to 175 about where the alarm would come on so I shut it down.

There may be some restriction in the cooling system somewhere. I did take off hoses and pushed water through them seemed clear

From what I read on the forums running hot some possible causes are:

Blocked pump jet pump engine inlet strainer or supply hose          *(maybe not on water hose)

blocked hoses

bad temperature sensors

blocked water passages

blocked exhaust

sand around cylinders

impeller clearance        **(not on water hose)