adam_k 19 Report post Posted February 18, 2017 Hey every one I have been having problems with my skidoo and I was wondering if anyone knew what was wrong and how I can fix it I have a 97 Yamaha venture 600 and as of last week my coolest cap started to blow off and keeps blowing off The tank everytime I drive it. I wired it on to see if it was a loose cap and it just literally exploded out the vent and emptying the tank in seconds when it happened last week we took the head apart and brought the head to the shop and they said it was off so they shaved it to the right specks and put it back together. Tonight was the first night I had I back so I took it for a gentle ride and about a kilometre away from the house it blew again coolant everywhere so this is my delema any advice would be amazing Cheers Quote Share this post Link to post Share on other sites
Some Old Guy 968 Report post Posted February 18, 2017 I ain't no pro mechanic or anything but if you have a bad head gasket that would pressurize your cooling system causing the failure....... Roger 1 Quote R.T.R. Respect the resource! Share this post Link to post Share on other sites
Bear 77 Report post Posted February 18, 2017 Thermostat stuck?? Overheating? Quote Share this post Link to post Share on other sites
Some Old Guy 968 Report post Posted February 18, 2017 Good one Bruce! I have even seen them in backwards! Roger Quote R.T.R. Respect the resource! Share this post Link to post Share on other sites
Bear 77 Report post Posted February 18, 2017 I would flush the system too, add new anti freeze. Being an older machine it probably could use some love. BB Quote Share this post Link to post Share on other sites
seppi 19 Report post Posted February 18, 2017 To build up pressure that fast ,I'm with Roger , sounds like a head gasket problem !! Seppi Quote Share this post Link to post Share on other sites
adam_k 19 Report post Posted February 18, 2017 The head gasket was just replaced this week when the head was brought in and fixed. Adam_k Quote Share this post Link to post Share on other sites
Some Old Guy 968 Report post Posted February 18, 2017 Everything I'm looking at for blowing a coolant cap off always goes back to the head gasket. Gasses blow by the gasket and get into the water jacket thus pressurizing your cooling system and your cap blows off. I understand it was just changed but sometimes new parts are broken parts. My record is buying three bad spark plugs right out of the package before I got a good one! Roger Quote R.T.R. Respect the resource! Share this post Link to post Share on other sites
Adrian 132 Report post Posted February 18, 2017 If you are blowing the coolant cap off, there is for sure a problem with either the cap or the tank. If you are getting excessive pressure in the cooling system, the cap will vent the excess pressure, but stay in place. I would look at the locking ears on the cap, and at the tapered collar on the tank to see if there is any wear, bent or broken areas. Quote Share this post Link to post Share on other sites
Fishbum 35 Report post Posted February 22, 2017 I would say try and flush the system.. it sounds like ( its not a cap issue not venting the pressure) than I would suggest that somewhere in you cooling lines the is a kink, or plugged ( partially even) this would allow you coolant to not properly circulate then it would overheat and can blow out the vent cap if it gets hot enough. Could be the wrong head gasket maybe.. plugging the coolant ports in either the head or the cylinders itself... try a flush and see if you can get fluid flowing through the entire system. Quote Share this post Link to post Share on other sites
Pro fisherman-Stud Muffin 420 Report post Posted February 22, 2017 Sorry but I believe U have a crack in head or bad head gasket or cracked cylinder or blown base gasket or cracked crankcase. Have coolant system pressure checked. .basically U Pressurize it .. once pressure falls u know u have an issue. Partsource may rent the tool to pressure test. U can pull carbs and y pipe u should see leak with coolant system pressurized. Do not run sled anymore till this is resolved. Pm me if u need further help Quote 2016 Dog Lake Open Champion. Thunder Bay BASSmasters Vice-President Share this post Link to post Share on other sites
Adrian 132 Report post Posted February 23, 2017 If you have a cracked head, blown head gasket, cracked block etc., you should see signs of coolant on the spark plug when you take it out after running it a little while. Run it for a little while till there is pressure build-up and than shut it down. Remove the plugs and see what you get. Even pull it over with the plugs out and see if coolant mist comes out of the cylinder. Quote Share this post Link to post Share on other sites
Pro fisherman-Stud Muffin 420 Report post Posted February 23, 2017 I wouldn't run it for diagnosis. if crankcase is flooded u could score the bearings. either pressure test it , or pull the block and tear it down. coolant systems run a bit of prerssure 10 psi ish (varries from applications). cap will relieve pressure if it is exceeded into overflow reservoir. the pressure is a result of temperature build up and expansion,, what u are experiencing is way more pressure, a water pump wont build much more than a few psi of pressure, and when a thermostat is closed the water pressure doesn't blow cap off ,so it wouldn't do that with a coolant blockage either. Quote 2016 Dog Lake Open Champion. Thunder Bay BASSmasters Vice-President Share this post Link to post Share on other sites
Resource Pimp 60 Report post Posted February 23, 2017 43 minutes ago, Pro fisherman-Stud Muffin said: and when a thermostat is closed the water pressure doesn't blow cap off ,so it wouldn't do that with a coolant blockage either. If your thermostat isn't opening or you have a coolant blockage you will defiantly overheat in the engine block and create excessive pressure that has to release somewhere. Quote "If people concentrated on the really important things in life, there'd be a shortage of fishing poles." Click on banner to visit Bedas Lodge. Share this post Link to post Share on other sites
Pro fisherman-Stud Muffin 420 Report post Posted February 23, 2017 23 minutes ago, Resource Pimp said: If your thermostat isn't opening or you have a coolant blockage you will defiantly overheat in the engine block and create excessive pressure that has to release somewhere. im just going by what he said ...."a 1km gentle ride". . so even with stuck stat it shouldn't reach boiling in a few mins. you are correct and sleds can have the same issue with a blocked coolant system but you wouldnt have it happen immediately. It would take a few mins to overheat/boil over and it wouldnt normally blow cap off, it would expand into overflow, engine would lose power, idle would change. etc. most sleds also have a temp light. overheating is rather obvious in sleds, they usually run under 150 deg, mine sits at 125 most days with snow on the ground.. when it gets to boiling you know it. not to mention the cap would be like grabbing an iron. Quote 2016 Dog Lake Open Champion. Thunder Bay BASSmasters Vice-President Share this post Link to post Share on other sites
adam_k 19 Report post Posted February 25, 2017 I will be working on the sled tommorow so hopefully all this info will help cheers Quote Share this post Link to post Share on other sites
