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Discussion Starter #1
Hi all,

So it looks as though I need to replace the valve stem oil seals on my bike, its burning oil on start up, ive not done a job like this before on a bike so ive been reading up on it and have some questions.

1. order in which I do things and if theres anything I am missing?

-remove anything attached to the head like exhaust, carb etc...
-remove cam chain cover
-remove cam chain tensioner
-remove cam chain sprocket.
-remove head
-remove valves, replace seals and build back up.

2. can the head be removed whilst the engine is still in the bike?

there is probably lots I have missed so any info/help would be much appreciated.

thanks in advance
darren
 

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Hi all,

So it looks as though I need to replace the valve stem oil seals on my bike, its burning oil on start up, ive not done a job like this before on a bike so ive been reading up on it and have some questions.

1. order in which I do things and if theres anything I am missing?

-remove anything attached to the head like exhaust, carb etc...
-remove cam chain cover
-remove cam chain tensioner
-remove cam chain sprocket.
-remove head
-remove valves, replace seals and build back up.

2. can the head be removed whilst the engine is still in the bike?

there is probably lots I have missed so any info/help would be much appreciated.

thanks in advance
darren

I don't know if you can view my picture link but we'll give it a shot. https://photos.google.com/album/AF1QipPwlLuOTvd5Z9AORfR9qF_5GJxf_611txEv60-n

Yep, you can pull to head off without removing the entire engine out of the frame as TW-Brian mentions. Good luck in your repair.
 

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I also bought the valve stem seat's as they didn't cost that much more.


Also, consider lapping your valves since you have it opened up. May not be necessary but it's pretty easy. I think forum member elime has a thread or pictures on here somewhere. Lots of info on the www as well.
 

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Here is the original post by elime on the 29th of April 2013 -

I was replacing the base gasket on my parts bike and figured as long as the head was off to lap the valves. For those that don't know what valve lapping is it is sticking a small rubber suction cup on the valve, putting some valve lapping compound between the valve and valve seat and spinning it back and forth. What this does is grinds the surface of the valve and valve seat so they have the same shape and makes for a good seal -- hopefully



.




This is my starting picture. The valves have already been removed, lots of carbon, and it looks like the valve stem oil seals weren't doing their job either. Arrows point to the valve seat.







A little later in the process. Most of the carbon in the combustion chamber is gone and the seats look a lot better.







A close up of the valve seats.







Before and after of the valves:



















The bike ran well but felt down in power. Along with the valve lapping I also installed new rings and valve stem oil seals. Reports to follow as to the results.

I forgot to include the really exciting picture of the head with the valves installed! Also I have discovered a "parts bike" is a bike you buy parts for. I used to think it was a bike one cannibalized then sold the remains to help offset the cost, but I was wrong.

 

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Discussion Starter #9
well I tackled this job yesterday.

Had a bit of a nightmare as I couldn't figure out how to remove the tappets(not sure if that's what they are called), because I couldn't remove these I couldn't get the springs out so I had to replace the valve seals with the springs in place which was a right pain!!
 
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