I am a new memeber and new to ATV'S...This forum looks great alot of knowledge here, it already has helped me with my '99 MOJAVE 250..But, now I have a problem with it overheating..and it happens in less than 10 min..no leaks, hoses are good, waterpump is circulating, no oil in water no water in oil, the thermostat was damaged so I removed it and left it without one for now, still overheats.. I do not have an overflow tank but the spout on the radiator near cap that would hook up to the reservoir is where the coolant dumps from when it overheats. I mean steam and coolant hot enough to scald..Has anyone seen this, what is it?

 

I don't have a water cooled bike, but just knowing what I know about autos, I would definitely run with a thermostat. It helps give the water a chance to cool off- it slows the circulation when it is cooler, allowing the water in the radiator to cool off more. Without a thermostat once your system gets hot, it will stay hot because the water flows too fast to get a chance to cool off. Also I would have a reservoir, even if it is a can with a hose in it and a lid on it to keep dirt from getting in and coolant from just pouring/splashing out. The last thing I would do is buy a new radiator cap to ensure the spring on it releases at the right pressure- the springs can wear out or stick. An extra thing you can do is buy a enhanced cooling product such as engine ice or water wetter (it is just an additive for your cooling system that helps it run cooler). A question for you- does your electric fan for the radiator kick on? I hope this helps.

 

Thank you. I really appreciate the time. I ordered a thermostat and radiator cap. I put a reservoir tank on today. The electric fan never kicked on for me and I wasn't sure if if it was due to the fact that I never had the ATV running for more than 10 mins, so I tested it w/a battery and the fan works...I'm just not sure about the temp. gauge. I spoke to a mechanice today, described to him what was happening and he thought it was either the thermostat or head gasket. My local shop only had the head gasket in stock, the other parts I had to order so I tore it down and replaced the head gasket. Maybe you can help me w/something else...I didn't move the chain on the crank and I think I know how to position the camshafts...but how do I know where top dead center is? Or can I put the camshafts in and leave everything the way it was before I tore it down? Thanks again.

 

also...its manual and kick start.....thanks again..

 

before you start, take off your cam chain tensioner and get that bar pushed in all the way into the tensioner, tighten the set screw in the tensioner so that it keeps the bar recessed, then reinstall the tensioner. http://fiche.ronayers.com/Inde.../Camshaft(s)/Tensioner On the left side of your engine at the top of your case cover there is a cap that goes in at kind of an angle (part 11012A). http://fiche.ronayers.com/Inde.../Group/Engine_Cover(s) Remove that and also remove your spark plug. Slowly crank your engine until you see a line or a "T" (if there are both types of markings, go with the "T", if it has an "F" and a "T", go with the "T") through the hole of the cap that you removed. When you see that line at the exact center of that hole look inside your spark plug hole and make sure the top of your piston is close to the top - it shouldn't be more than about 3/8 of an inch from the inner part of the spark plug hole. That is top dead center. Your cams gears should be keyed so they only go on one way. There should be marks on the cam gears and somewhere on the head that they align with. after all these are lined up and you chain is on, then you can loosen the bolt on your tensioner to put tension on your cam chain. That should be all there is to it. SLOWLY crank everything for a couple of revolutions to ensure that all the marks line up at the right times, and that there is not any kind of mechanical impact (piston hitting your valves). Hope that helps. Also, I dont know where the temperature switch is for the fan on the mojave but that could be why your fan isnt kicking on, but if you want to bypass it you could direct wire your fan with a switch so you know for sure that it is running, just be sure to shut off the switch when you are not using it or you can hook it up to a wire thats only got power when the ignition is on.

 

Thank you so much...I guess I am a little confused on the whole tensioner thing??? I took off the bolt tensioner, actually all three bolts I believe and removed it entirely.(12048). As I put the head on today, I held the top part of the chain up while installing the head since I never moved the bottom of the chain around the crank. As I lowered the head down I made sure chain guide on left(12053a) was left and chain guide on right (12053) was to the right. I guess I am confused as how the tensioner actually works when installing it back in? Do I first put the cams in then chain then tensioner? This part of your reply is basically my confusion "take off your cam chain tensioner and get that bar pushed in all the way into the tensioner, tighten the set screw in the tensioner so that it keeps the bar recessed, then reinstall the tensioner"...Also I removed the cap (11012a)and it looks like there is a letter "v" starring at me...will be wiring my fan to a switch..I hope to have this thing running by the weekend, it takes forever to get parts for Mojaves.waiting on radiator cap and thermostat...I really appreciate your knowledge on this...

 

if you can get everything lined up without pulling the sprockets off of the cam, go for it. If you cannot, then pull a sprocket and put the chain around it and slip it back on the cam. Pulling only one sprocket should give you enough slack in the chain to do this. The tensioner should have a spring that pushes out on a metal bar. My tensioner is set up a bit different- mine I can get the metal bar recessed into the tensioner (I have to slide off a locking ring first though), then tighten a screw to keep it recessed. When I need to let the bar out, I just loosen the screw, bar slides out, then I re-tighten the screw to hold it in place. If yours cannot do that then maybe on yours you get that bar recessed without putting in the 3rd screw, install it with the 2 mount screws, then put in the 3rd screw to put pressure on the spring that pushes out the bar. Play around with it off the machine to see how it works. Basically you dont want to bolt it to the machine as it is putting tension on the chain, you want the chain to get the tension AFTER the tensioner is bolted to the machine, hopefully that makes sense. if the only mark that you can find under the cap is a "v" then use that. There may be other marks under the cap that you may find as you crank it- watch for them. Since you havent moved anything, I would go ahead and put it together as it is and then see what happens. just make sure that after you get the pieces together to slowly crank it and ensure that all the marks line up and that there your valves dont touch your piston. If you get the opportunity to buy a service manual for your atv, it is a good investment so you know for sure that you are getting things together exactly the way they should be.

 

Thanks again...I think I figured it out...My tensioner does not hold compressed with set screw so I had to hold it with screw driver compressed as I reinstalled it then tighten down side screws then release tension. It seemed to work, other than that I followed your steps and what was in manual; cranked it over slowly a few times..Nothing hit or made a wierd noise, it seemed to move smoothly/freeley except at one position which I think is probably when piston is moving up, and each time around everything lined up at TDC. I did find the "T" I lined it up, set cams in position as described in manual set chain on cams put tensioner in released tensioner, tightened everything down cranked it a few times and all seems to be good.(cross my fingers) I also wired the fan to the light switch, and put a reservoir tank on. Now I am just waiting on some parts I ordered to complete the job( radiator cap, thermostat) I will probably have them by next week, slap it together fill radiator crank it over and pray for the best! I will keep you posted, I'm sure I will have more questions in future. Again thanks for your help.

 

I am glad you got everything together so smoothly. That is awesome. Wiring it to the light switch was a great idea. I am excited to hear how it all turns out for you, but probably not as excited as you are [img]i/expressions/face-icon-small-smile.gif[/img] Let me know how it all goes.

 

Will do!! Thanks again, talk to you next week.