is valve job necessary?

Me and my dad drove around for a while today and we discovered that my dads bike leaks oil like the gulf spill.. All of this oil seems to be coming from the upper head gasket. If we put in new head gaskets, is it manditory to do a valve job as well? The bike still runs good but it seems to leak quite a bit of oil.

also, the bike is a 1981 KZ1000LTD with a CSR motor.

A leak down test will let you know if the valves are sealing properly or not. Although, if the head gasket is leaking that bad it might be difficult to tell.

no reason to do a valve job for a leaking head gasket, but depending on mileage etc when the time comes to replace head gasket if you suspect a problem with valves,seals,or guides that would be the time to do it since head is off for the gasket replacement.

Kitten Tooth wrote:

Me and my dad drove around for a while today and we discovered that my dads bike leaks oil like the gulf spill.. All of this oil seems to be coming from the upper head gasket. If we put in new head gaskets, is it manditory to do a valve job as well? The bike still runs good but it seems to leak quite a bit of oil.

Seems unusual for so much oil to spring from a head gasket leak.

Perhaps it's not from the head gasket.

Could inject air pressure through a spark plug hole, each individually while other plugs remain installed, to see whether pressure escapes in area of oil leakage.

Would clean engine, allow to dry, spray all around with foot powder deodorant spray (head gasket, valve cover gasket, tach drive, exhaust clamps) to have a clean white covering.

Then crank and run engine to positively determine source of oil leak.

There is only one head gasket (maybe a two-piece head gasket) between the head and cylinders.

If by the "upper head gasket" you mean the valve cover gasket, which is the gasket between the valve cover and the head, which is of course above the head gasket.

The valve cover gasket is a common source of oil leakage.
It isn't exposed to compression from the combustion chamber.

A blown head gasket is more likely to spit and cause loss of compression from the combustion chamber. And is likely to impair engine performance.

A bad valve cover gasket is more likely to leak oil.

Would first suspect leak source being at valve cover gasket, tach drive, or exhaust gasket.

Good Fortune!

you had the head off for some reason,guessing maybe it was leaking before?
I would at a min replace the valve seals, and clean and relap the vlaves, but if it was mine I would get the head done, then you know the guides seats and valves are in perfect condition also have someone check to make sure the head if flat.
when you had it off before, what was the condtion of the clys and rings, again, for a few more dollars, if they are still within specs, I would repalce them.

We haven't had the motor apart before except for the valve cover. A tiny bit of oil comes from there due to us getting the wrong torque wrench and just cranking things down by feel.
Since this CSR motor went ito the LTD frame, all of his gauges are electronic and there is no cable in place for the tach drive. Also i think it has a bad seal for the tach drive so that spits a tiny bit of oil as well. But, there is no way that there could be that much wet, fresh looking oil on the front of the motor just because of those two little spots. From what i have heard so far though, unless i have suspissions about the condition of the head, just leave them be. My dad wants to put the gasket in himself which is fine and i bet its really not tremendously tough or anything but.. not to sure really how to go about servicing the head. I think we would let a mechanic mess with it while we watched so we would know what to do next time.. OR just refer to the manual:D

If there is no tach cable attached, it would likely leak oil there.

bountyhunter wrote:

If there is no tach cable attached, it would likely leak oil there.

x2

You need a tach blockoff if there is no cable installed there. Heck alot of them leak at the tach drive even when there is a cable in place.

My mistake, I missed the "if" word.
how many miles are on the motor?

just my comfort level when I pull a motor down I like to put it back right I dont like having to do things twice.

as was stated before, clean it off and make sure to pin point the leak source then make a decision on what needs to be done from there.

The head is not hard to remove and replace, but you do need a book on it and follow the steps.

one other thing to look at while inside, look at the timing chain and idlers and the tensioner components.

If u put a CSR motor in an LTD frame,CSRs had cable driven tach and speedo,LTDs and J bikes had electronic instruments.Maybe u put the LTD motor in the CSR frame?Frames were identical.bj

The tach cable connection and a valve cover leak can piss out a half litre of oil in a 1 hour ride! TRUST ME.

Just pull things apart and seal them up correctly.

If you have a bad head gasket leak with oil, you're going to have performance issues.

Oh yeah, valve question... no. If valves are sealing correctly via leakdown/compression test, then leave them alone.

GL.