fixersteve26

Hi Guys, Im hoping someone can help me with this as i am tearing my hairout!

I have a Yamaha XL700 Waverunner, A few months ago it developed a problem of overheating. This was caused by it sucking a huge amount of sand into the cooling system while doing safety cover for a surfing event. Causing it to go into Limp mode.

I have taken all the cooling hoses out from the pump to the block and all pipes between the block and exhaust, and all the pipes returning back to the exhaust out let. these are all now clear. So i put it all back together and had it runing for 20mins on a hose outside my workshop and i have plenty of water coming out the tell tail.

So i put it in the water and took it for a trial run and had no problems until the baffel box of the exhaust started to overheat. So out the water it came and i set to work stripping the exhaused manifold to find it full of sand and not alowing water to cirulate around the cooling part of the manifold.

I have cleaned all the dried salt and sand out of the exhaust and put it all back together and put it in the water this afternoon. only to get 50 meters from shore and the ski to go into limp mode because of no water going throught the engine. I have plenty of pressure coming out of the jet and the impeller isnt worn.

SO! Can anyone help me!!!??

Many thanks Steve

tiagobaracho

Hello steve, how are you doing ? When you say you have plenty of pressure coming out of the hose you mean that you took out the hose that goes to the engine and saw the flow ?
The best thing to do and solve this problem for all would be you get the head off and see the water ways if are clear and clean everything... buy a new head gasket and assemble it back.. But i am assuming you are not willing to disassemble right ?

So, what you could do in this case is ... find a really strong water hose and plug it on the inverse direction.. turn on the engine first, then plug it on the head outlet and plug another hose on the exhaust and see if sand is coming out....
try to use this idea of pluging the hose on the opposite direction then on the righ direction to move the sand inside out of the engine... But sincerely you should buy a gasget kit and disassemble it, clean it all and assemble back. I don´t know how long ago this engine was clean, but if it was a long time ago, it may have a lot of debris inside... and if you do not use the hose just after each use, it may have a lot of salts complex inside..

how long it does since the last cleaning inside the engine ??
Did you try to blow air, while clogging the exhaust to see if there is a lot of resistance just with air ?