top end questions

[Yzrider1023]

so i bought a 2006 yz 450f a few months ago now and now it burnt a half quart of oil in 6 hours of riding so i think its top end time i have a few questions on it though 1 is it worth doing it yourself? 2 are there any special tools i need ? 3 how easy is it to do?

[billygildark5007]

Is the exhaust smoking when running? If yes and it's a more bluefish color than white or black it's burning oil. The piston rings or valve seals being the most likely culprits.

For the top end you need

Service Manuel (most valuable tool)

Metric socket set and Allen set

Normal hand tools

A good torque wrench

Piston ring compressor

Valve spring compressor (if replacing valves)

Feeler gauges

If it's your first top end you'll have fun if your not mechanically inclined. just take your time and follow the service Manuel, they'll be a few mistakes on the way but consider them a learning experience. Once you get threw your first they are easy

[billygildark5007]

Also post in the make/model specific. All your future questions or problems in the build can be answered there.

[Yzrider1023]

Is the exhaust smoking when running? If yes and it's a more bluefish color than white or black it's burning oil. The piston rings or valve seals being the most likely culprits.

For the top end you need

Service Manuel (most valuable tool)

Metric socket set and Allen set

Normal hand tools

A good torque wrench

Piston ring compressor

Valve spring compressor (if replacing valves)

Feeler gauges

If it's your first top end you'll have fun if your not mechanically inclined. just take your time and follow the service Manuel, they'll be a few mistakes on the way but consider them a learning experience. Once you get threw your first they are easy

It smokes when I start it up then once its running it doesn't smoke but the exhaust smells weird

[billygildark5007]

Sounds like you might need valve seals. Hopefully not the guides or the seats. But you will only know if you tear into it.

[Yzrider1023]

Sounds like you might need valve seals. Hopefully not the guides or the seats. But you will only know if you tear into it.

Would it burn through that much oil from just valve seals?

[billygildark5007]

Possible. Oil should only enter the combustion chamber threw the bottom ( bad piston rings) or threw the top (threw the valves). Since the smoking goes away at rpm it's more likely the valves. Maybe the seals went bad over time or the valve stem is bending causing the seal to leak. Either way it's gotta be fixed.

Have your valve clearances changed in the last few rides?

[grayracer513]

"Through"

 

The "weird" smell could be coolant, probably from a head gasket.  All the same, time for a top end.

[Yzrider1023]

"Through"

The "weird" smell could be coolant, probably from a head gasket. All the same, time for a top end.

I'm not burning coolant though it smells more like oil burning than coolant

[Slow and Jerky]

All things considered the top end is not bad, normal tools, good torque wrench and feeler gauges. You won't need to pull the engine. You don't need a ring compressor. Download the manual if you don't have one. I recommend getting OEM parts, particularly the gaskets. Chances are it is the the rings but while you have it apart it wouldn't hurt to change the valve seals (which  requires a valve spring compressor) and replace the timing chain. Keep in mind that you can't "lap" the valves on these, so if they are leaking you will need to have the seats ground, etc. Take your time and take pictures!

[billygildark5007]

[quote name="Slow and Jerky" post="12201166" timestamp="1423533170". You don't need a ring compressor.

I am curious how do you do rings without one?

[Yzrider1023]

[quote name="Slow and Jerky" post="12201166" timestamp="1423533170". You don't need a ring compressor.

I am curious how do you do rings without one?

You can roll them on which I wouldn't recommend it can weaken the rings there's a video on YouTube on how to install them without a ring compresser

[billygildark5007]

I'm sorry I'll rephrase my ? How do you get the piston in the cylinder without one?

[grayracer513]

You compress the rings by hand, using the slots at the base for and assist.  Be VERY careful not to snag the exposed ends of the oil ring scraper rails as you go, or you may roll one out of the groove and fold it over.  That, BTW, can happen with or without a compressor.

[Slow and Jerky]

The bottom of the cylinder has a slight bevel, but like gray said you have to be careful not to let the oil rings catch. 

[billygildark5007]

Interesting. I've never seen or done it that way before.