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About mcdx

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  1. I hear you. Too little too late, But for me since I bought a left over 2017 FE 450 this year it worked out (I hope). Oberon sounds like a solid way to go. Still waiting for Magura to provide me details on what I should use and what assembly problem they had. I suspect you are right that someone used the wrong lube at the factory.
  2. Magura is standing behind their product and sending out free replacement piston kits to those that contact them directly. They told me it was an assembly issue in the factory no details. The directions my replacement came with say to used the supplied grease(not supplied) to lube the seals before assembly. I assume it is silicone based.
  3. mcdx

    Nikasil plating

    send the piston in with the cylinder. They will match them to fit. Millennium does good work.
  4. mcdx

    2007 YZ450 Overheating

    BTW where is that hill climb? Looks awesome!
  5. mcdx

    2007 YZ450 Overheating

    Would you want to run your coolant temperature to 387F? If you operated this way cylinder head temperatures would easily be over 500F roasting the engine,yet no boil over. Simply raising the boiling point doesn't make your engine run cooler,it simply raises the point at which it doesn't puke coolant out. Having better heat transfer qualities such as pure water is good but it boils at 212F while not under pressure. Under pressure the point at which it boils is even higher. Adding antifreeze raises the boiling point even higher. At some point the heat transfer quality and boiling point ratio reach a point where a higher boil point versus heat transfer quality begin to have diminished returns. I assure you an engine will actually operate at a lower temperature with less than 100% antifreeze to water ratios. How much cooler I can't say,simply pointing out that if it doesn't puke coolant out doesn't mean your engine isn't getting hotter than designed.
  6. mcdx

    2007 YZ450 Overheating

    Not trying to get into a mine is bigger than yours debate. Simply stating facts about how antifreeze(coolant) works. Doesn't discount that you could run straight antifreeze and not have problems, it simply doesn't transfer heat as well as pure water, that is a fact. We are not talking about enormous differences in heat transfer but measurable. 70/30 is a good ratio , any higher is a waste of coolant. Higher pressure cap will do more for boil over protection than 70/30 or 100% coolant.
  7. mcdx

    2007 YZ450 Overheating

    I live in So.Cal too. I've never needed more than 50/50. If you really want to raise the boiling point use a higher pressure cap or go to Evans coolant. As you increase the ratio the actual heat transfer goes down yet the boil point goes up. Sort of like it doesn't boil over now but runs a bit hotter.
  8. mcdx

    2007 YZ450 Overheating

    As many will tell you these are race bike and don't like to put around however check the obvious things like proper coolant level, 50/50 mix is fine. Water is actually better for heat transfer than antifreeze but antifreeze raises the boiling point and reduces corrosion. Proper jetting and a clean idle circuit are a must as well. from your description it doesn't sound like it is actually overheating. going to a 1.6 bar cap will help too.
  9. so the Brembo piston kit and seals fit the Magura? Sounds good. You have a P/N?
  10. Good to know. Magura just sent me a rebuild kit free of charge. Made it a point to ensure I fully lubricate the seal and rotale it CCW and Cw a few time before installing it. Seems if you reach out to them directly they support you.
  11. I'm at 27 hours and 780 miles on my 2017 FE 450. Called Magura waiting on a call back. Mine has not failed yet. Have a call into my dealer as mine is still under the 6mos warranty hoping for a proactive fix. I want options on the ready for the time it fails. I hope the replacmnet parts you received last and the problem is resolved.
  12. mcdx

    YZ 450 piston/crank seize

    should mention I meant magnetic metal pieces!
  13. mcdx

    YZ 450 piston/crank seize

    looks like my rod bearing radial play was way too much and was shedding metal despite the axial play being in spec. going to replace the crank and both crank case crank bearings. and the oil pump rotors becauser they ate some metal.
  14. picked up an 08 Yz 450 that was seized up. owner said that the air filter had came off while riding in the desert. Tore engine down completely found metallic pieces of metal in oil and mild seize marks on the piston skirt predominantly on the exhaust side. rings appeared ok as did the crown and ring lands. inspected the transmission gears all looked good. Crank big bearing axial side play was about .012-13 and rod spins freely on big end. Not much radial play "by feel". .002 is spec. Replaced the center intake valve and had the seat cut all of the remaining valves looked good for 142 hours on the meter. Was told the piston was replaced at 100 hours as a preventative measure. reassembled the bottom end installed a new cylinder and vertex piston from cylinder works. Bike ran great for .8 hours and I began to notice that upon letting off the throttle I could tell it was trying to seize again as I felt the rear tire lock up on a jump but fired right back under more throttle. Shut it off and drained oil and filter only to find the same metal in the filter and oil. Identical piston damage only this time the cylinder was not damaged. The oil pump gears measure good and all of the oil passages and jet are clear. The piston was matched for the bore size so I know that it is not a piston fit or ring gap issue. I know 142 hours is a fair amount on a crank but it good compared to ones I have replaced before . My KTM crank went bad once and shed metal like this and the piston was damaged in the same manner however the rod was so loose it was obviously bad. I did notice that the crank had a decent amount of axial play in the case but unlike the KTM there is no way to control the thrust. The case bearing roll just like new and don't make any noise in fact compared to a new set they seem about the same. Can too much radial big end bearing play cause the piston to seize? If so what is it causing the skirt to rock harder that it would under full throttle acceleration? I worked on a CRF 450 that had similar but upon tear down I could get the rod to lock up at times by pulling while I turned it so it was clearly bad. ideas. manual has no spec on crankcase to crank axial clearance. I have no problem replacing the crank, cranck case bearings and piston but I want to understand the piston seizure. yes it was full of oil and I checked to see that oil was flowing by checking the bolt on the back of the cylinder on the first start up.