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Two-Six

Coolantin oil again

10 posts in this topic

Hey guys I rebuilt my 06 YZ450F last november with a new crank, piston, rings, and new gaskets. I didn't follow the torque specs in the manual and of course the head gasket leaked. There was a ton of coolant in the oil. I replaced the head gasket and base gasket then followed the torque readings.

I rode it twice since the rebuild, after the first ride there was no coolant leaking and the oil looked good. After the second ride the crankcase got broken because of a chain. The bike has been sitting since November waiting on parts to fix it. I got the new cases in and when I drained the oil it had water in it, the water came out before the oil did on the drain bolt by the clutch cover. The drain on the other side of the bike had no coolant come out of the oil and the oil wasn't milky on that side.

I am taking the engine apart to replace the cases, so it will have fresh Athena gaskets and seals. Come someone let me know what else I should order to fix this problem. I am guessing it has something to do with an O-ring on the right side because the coolant came out the right side drain bolt and not the left.

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Did you change the base gasket when you changed the head gasket? There's a passage there, too.

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Did you change the base gasket when you changed the head gasket? There's a passage there, too.

Yes, I used cosmetic the first time. When I replaced them the 2nd time I used OEM gaskets.

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bump......

Grayracer I have searched and seen threads with guys having the same problem as me. Can you please take 2 seconds of your time and give me the part number or show me on Microfiche the seals I need to prevent this happening again?

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I don't know why you are replacing the cases, but if you are doing that, and using a complete gasket set, I don't see what the problem is.

What you need to do is to trace the path followed by the coolant in the engine and be sure everything is in good shape all along the way. Coolant flows directly to the water pump cover from the radiators. From there, it flows to through the right crankcase cover to the crankcase. Be sure the sleeve and O-ring at this point are in place (items 12 & 13 on the water pump page of the parts fiche ). From there, it travels through the crankcase to the cylinder base, up through the cylinder to the head, then out through the outlet pipe to the radiators.

Check that there are no cracks or porosity in the right crankcase cover, the right crankcase, the cylinder, or the head, and that all sealing surfaces are in good shape and flat within specs. There is an Allen socket plug in the center of the head between the cams. Be sure it's tight. Be certain that the water pump drain hole in the right crankcase cover is clear through to the impeller shaft, too.

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sounds like you are doing a half arse job here honestly. why would you not follow the torque specs especially on the head bolts?

then you have a chain break and take out a case?

seriously take some time and inspect the bike. If it looks suspect then replace it. Replace all the sealing Orings and gaskets and make sure the surface is prepped and clean. You might be better off in the long run to take the bike to someone to repair it for you. Might be cheaper for you instead of doing everything 2-3 times. Sorry to be honest here, but needs to be said.

If you do replace all gaskets, get the cases sealed properly with the Yamabond4 , then get the cylinder fluxed

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I don't know why you are replacing the cases, but if you are doing that, and using a complete gasket set, I don't see what the problem is.

What you need to do is to trace the path followed by the coolant in the engine and be sure everything is in good shape all along the way. Coolant flows directly to the water pump cover from the radiators. From there, it flows to through the right crankcase cover to the crankcase. Be sure the sleeve and O-ring at this point are in place (items 12 & 13 on the water pump page of the parts fiche ). From there, it travels through the crankcase to the cylinder base, up through the cylinder to the head, then out through the outlet pipe to the radiators.

Check that there are no cracks or porosity in the right crankcase cover, the right crankcase, the cylinder, or the head, and that all sealing surfaces are in good shape and flat within specs. There is an Allen socket plug in the center of the head between the cams. Be sure it's tight. Be certain that the water pump drain hole in the right crankcase cover is clear through to the impeller shaft, too.

Ok I am using a complete gasket kit and brand new cases. So I am guessing that everything will be fine this time. The only thing that is worrying me is that the first ride after the head and base gasket were replaced the coolant was fine. Then after I broke the case on the second ride the bike sat until I got parts for it and when I did drain the oil a couple of days ago there was cooant in the oil.

I am having a mechanic assemble the lower and and I am doing the top end. Will the o-ring which is number 13 be in the gasket kit? I would look but I just took the motor to him. If it's not then I will order it and get him to put it in unless it's a easy job.

Is it a easy job? and should I wait untill I get it back together to see if it still leaks to worry about it.

I know for sure the head and cylinder are fine because before I replaced the crank and top end the bike never used an ounce of coolant.

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sounds like you are doing a half arse job here honestly. why would you not follow the torque specs especially on the head bolts?

then you have a chain break and take out a case?

seriously take some time and inspect the bike. If it looks suspect then replace it. Replace all the sealing Orings and gaskets and make sure the surface is prepped and clean. You might be better off in the long run to take the bike to someone to repair it for you. Might be cheaper for you instead of doing everything 2-3 times. Sorry to be honest here, but needs to be said.

If you do replace all gaskets, get the cases sealed properly with the Yamabond4 , then get the cylinder fluxed

I did follow every thing in the manual except the part where it says to use moly grease on the head bolts and I got a false torque readings.

The chain was in perfect tension before I went out and I quess I had some bad luck because it broke. It was an O-ring chain and nothing was wrong with it.

I do inspect my bike and take great pride in my work. I have just had some crappy luck with it these past couple of months. I am a race mechanic myself and know my way around a bike, all I wanted was some assistance from grayracer because he knows way more about a YZF than anyone I know.

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