Minkia38 Posted December 6, 2007 Report Share Posted December 6, 2007 can anyone hook me up. I have bone stock yfz450 that is giving me some potential trouble. The bike runs perfect. BUT, when the bike is cold, the oil level is perfect. After some good hard riding, the entire oil reservoir fills all the way up to the top!!!! I know its not radiator fluid, so it must be gas. any idea what might be causing this? Compression is GREAT, because i checked, becuase I thought it was my rings...... please help Ray :.s. FREE shipping on any (no frames, heavy items etc) ebay item of mine to the person who correctly answes this question. Quote Link to comment Share on other sites More sharing options...
blowit Posted December 6, 2007 Report Share Posted December 6, 2007 can anyone hook me up. I have bone stock yfz450 that is giving me some potential trouble. The bike runs perfect.BUT, when the bike is cold, the oil level is perfect. After some good hard riding, the entire oil reservoir fills all the way up to the top!!!! I know its not radiator fluid, so it must be gas. any idea what might be causing this? Compression is GREAT, because i checked, becuase I thought it was my rings...... please help Ray :.s. FREE shipping on any (no frames, heavy items etc) ebay item of mine to the person who correctly answes this question. Carb issues if you are sure it is not coolant. You should easily be able to smell what is going on. Gas ain't good and will toast your motor quickly. You may look at your float level, needle and seat, and pumper adjustments. Brandon Quote Link to comment Share on other sites More sharing options...
Skithis Posted December 6, 2007 Report Share Posted December 6, 2007 Carb issues if you are sure it is not coolant. You should easily be able to smell what is going on. Gas ain't good and will toast your motor quickly. You may look at your float level, needle and seat, and pumper adjustments. Brandon Its a 4 stroke dude. Carb has nothing to do with it. IF IT IS GAS...then its most likely coming from either bad rings but idk if ive ever heard of that happening, usually its the oil that goes up top and gets burned, not the gas coming down. Or you have bad valve seals, but also ive never heard of gas running down into the case, only oil coming up and getting burnt. IDK anything about 450's really. Id just walk into a dealership and ask somebody about it. Maybe its normal for a 450. Can you stick your finger in the oil and smell the gas on your finger? Quote Link to comment Share on other sites More sharing options...
Bansh-eman Posted December 6, 2007 Report Share Posted December 6, 2007 are you sure its filling up and not just heating up making it look like theres more fluid in there? Quote Link to comment Share on other sites More sharing options...
blowit Posted December 6, 2007 Report Share Posted December 6, 2007 (edited) Its a 4 stroke dude. Carb has nothing to do with it. IF IT IS GAS...then its most likely coming from either bad rings but idk if ive ever heard of that happening, usually its the oil that goes up top and gets burned, not the gas coming down. Or you have bad valve seals, but also ive never heard of gas running down into the case, only oil coming up and getting burnt. IDK anything about 450's really. Id just walk into a dealership and ask somebody about it. Maybe its normal for a 450. Can you stick your finger in the oil and smell the gas on your finger? I would say someone needs to go back to school if they are saying rings or valves would cause this. I am aware it is a thumper and yet again, the carb WILL cause this. There is a pumper or accelerator pump in the carb and can fail and way over pump fuel to the engine. This should cause it to run like crap though. IS it possible you have it way over full on oil? They are tricky to fill. DId you read the manual when filling? We have seen it toooo many times where a guy will over fill and it is easy to do. Brandon PS, just to clarify, I am more worried about the fuel seeping in when not running. Really would not make it by the rings while running unless motor is shot. Edited December 6, 2007 by blowit Quote Link to comment Share on other sites More sharing options...
jbooker82 Posted December 7, 2007 Report Share Posted December 7, 2007 are you sure its filling up and not just heating up making it look like theres more fluid in there? That is exactly what my raptor 660 does. If you dont check the oil when it is hot, and you fill it up to make it at the full line. Next time you check it after riding when it is hot it will puke out the dip stick hole. It is real picky. Quote Link to comment Share on other sites More sharing options...
Minkia38 Posted December 7, 2007 Author Report Share Posted December 7, 2007 thanks for the responses. Yes, I first thought it was the float as well, took it apart, set it a little higher, and it still did the same thing. The oil is perfectly level when its cold, when its hot, it spews out the overflow tube on the case breather and into the airbox as well. I dont think the oil would expand THAT much....... I cant kinda smell gas in it, but im not really sure. If left alone a few hours to cool down, the oil settles back down to the correct level..... Quote Link to comment Share on other sites More sharing options...
YFZ350kid Posted December 7, 2007 Report Share Posted December 7, 2007 when i had my 450, if you filled the oil level to the max mark while cold, it would spew out when it got hot. only fill the oil tank to about 1/4 the way up the safe marks on the dipstick. the oil does expand that much. Quote Link to comment Share on other sites More sharing options...
tedd1 Posted December 9, 2007 Report Share Posted December 9, 2007 These scooters use a dry sump oiling system. While the motor is running, most of the oil is in the tank. When you shut the motor off, most of the oil in the tank will want to drain back into the crankcase. If you fill the tank at that point, yes it will overflow. To accurately check the oil, you have to run the motor a few minutes, shut it down, then immediately check the oil with the dipstick. Quote Link to comment Share on other sites More sharing options...
Minkia38 Posted December 9, 2007 Author Report Share Posted December 9, 2007 These scooters use a dry sump oiling system. While the motor is running, most of the oil is in the tank. When you shut the motor off, most of the oil in the tank will want to drain back into the crankcase. If you fill the tank at that point, yes it will overflow.To accurately check the oil, you have to run the motor a few minutes, shut it down, then immediately check the oil with the dipstick. thanks for all the help guys who needs free shipping? Quote Link to comment Share on other sites More sharing options...
FireHead Posted December 9, 2007 Report Share Posted December 9, 2007 I would say someone needs to go back to school if they are saying rings or valves would cause this. I am aware it is a thumper and yet again, the carb WILL cause this. There is a pumper or accelerator pump in the carb and can fail and way over pump fuel to the engine. This should cause it to run like crap though. IS it possible you have it way over full on oil? They are tricky to fill. Did you read the manual when filling? We have seen it toooo many times where a guy will over fill and it is easy to do. Brandon PS, just to clarify, I am more worried about the fuel seeping in when not running. Really would not make it by the rings while running unless motor is shot. My $.02: 1.) A carb that has a needle valve stuck open can flood the cylinder, however the bike you probably run poorly and if enough fuel found it's way into the combustion chamber you could potentially loick up the engine and bend the con-rod. 2.) Due to the dry sump on the engine you may see a great difference in oil level between checking the engine when it is cold vs. hot and running vs. not. ...............and because I am a retard, I have now read to the bottom of this thread and found that the problems has been solved? Quote Link to comment Share on other sites More sharing options...
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