I have thought about having some work done to the head while it is off. But it will be something I have to think about since it is not leaking. I was at least going to do new valve guides and a valve job. Probably not going to do any porting other than maybe cleaning up the stock casting. How much would you need to deck the head to get that kind of compression? I have not been able to find aftermarket headers or a full exhaust. I would like to have some headers, that would work better with my exhaust plans. I heard hindle is making them so maybe I will give them a call. I am not really worried about being in line with newer liter bikes. I want to enjoy my bike and am not much of a racer. I do my style of riding and don't really worry about anyone else. I abused the **** out of my ninja 250 but learned its a little sketchier on my 600rr.

 

Here is what the cylinder walls look like in all 4, this is #4.

 

Calculating the chamber volumes to see what the compression ratio is goes beyond my skills. That kind of job i would leave to professional. You could measure the oem head gasket and call Wiseco or Cometic to see how thick head gaskets do they have. I think they are the only ones that make head gaskets to 954. If they have a thinner one i would go whit that whitout any decking. If they have a thinner gasket they will probably know how much it will raise compression ratio. Not much.

Actually whit the valve job i ment getting the seats done by a machine that is
ment for valve seats. You should ask some reputable head shop how much they will charge you for valve seats and a porting if you send them just the bare head and disamble it yourself.

 

I decided that the head is not going to work for me in it's current condition. I cannot rebuild the engine and it be completely fresh and put a dirty head on it. The intake ports are very clean and have no build-up but the exhaust side has so much carbon build up that it is not going to cut it for my pickiness. So I am going to disassemble the head have it and the rest of the parts cleaned by a local machine shop. After it is cleaned I am going to take back possession of the head so I can smooth out the stock casting marks and eliminate the roughness (I did this on my Camaro heads along with gasket matching, no gasket matching needed here.) And after I am done with that I will take the head back to the machine shop for a full valve job and valve guide replacements if needed. Do you still have to lap the valves in if you do a valve job? This should allow the head to flow better and be more efficient with just the smoothening out and polishing of the ports. To be honest I don't know how much you can port these safely with the ports not having a lot of excess metal as is. Plus I may need a new radiator if mine cannot be repaired.

 

Do NOT polish your intake ports. Make sure you don't go finer than 60-80 grit or so. If a machine shop is going to do the valve job - they'll probably lap in the valves, if not, it's not a had process to do, you can do it.

 

Wow... That is ****ty..... but mine looked similar. As Mika discovered, that alusil stuff did not do the 954 any favors... And I'm surprised to not see more carbon build up on the piston dome... that looks pretty morose!

 

Here are few photos of my head which is professinally ported. You can use it as a guideline when you start to grind your ports.

Major 929 Rebuild - Page 8 - Honda Motorcycles - FireBlades.org

I would lap the valves my self. Just get the valve seats done by serdi or something similar and valve guides machined whit right size reamer if you don't have one your self and change everything that is out of spec. Check the valve springs very thoroughly. If they are still in spec but the free lenght is much shorter then on new springs i would change them anyway. I would do the ports before i would send it to machine shop so it comes fully clean back from there. Like Conrice said don't polish the ports. Check out how rough my ports are. The air should flow better and the fuel mix to the air when they aren't polished.

 

I only intend to remove some of the casting marks in the ports. Not necessarily a port or polish. The machine shop is going to do a valve job and lap in the valves for around $250 or so, this includes 3 separate cleanings as well.

 

Yeah the cylinder wall coating did nothing for the bike. But, the pistons will now be coated also and will have a tighter piston to wall clearance so I should not have anymore problems. The pistons look pretty darn clean on the top as well as the combustion chamber but the bike does only have 10,000 miles on it. It is a shame the previous owner could not keep oil in it and abused it.

 

Well I am hoping the valve guides are still within spec as well as the springs. I am not building a race engine here so I don't want to replace anything that does not need replaced. I am only doing work to the head because of how dirty the exhaust ports are. Hell I may just have everything cleaned, do some minor porting, lap in the valves, and have it all put back together. This has got to be a budget build, but I also want to do things right so I do not have problems later. I will fix and replace anything that needs done, but if it is not broke or in need of replacement and still within spec than that is good enough for me.