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Discussion Starter · #1 · (Edited)
Hey all, fairly new guy here. To keep things brief, my CL360 seems to have minor crimping/dishing on top of the left side exhaust and intake valves. (Likely due to timing neglect on previous owners part.) All the same, that gives me a fairly large first project with the bike. I'll be documenting my process in disassembling the head, inspecting the valves, replacing the valves, lapping said valves, reassembling, and likely doing valve timing. Dreading that last part. A previous thread was made when the valves caused clicking noises on the left side of the engine. You can read that here if you want some back story.

I'm a complete greenhorn mechanically, so I appreciate any and all patience you have to offer. I know it's frustrating dealing with guys like myself in your experience position. I'm a bit intimidated with such a large teardown, however, I'm equally excited to get into things and hands on. (And to hopefully save some money on mechanic costs of course.) At the moment I'm gathering the tools I'll need for the valve work. Once I'm in there and can get opinions on the damage extent, then I'll pick up the parts I'll need. Carbs and timing mechanism still need removed before I can start on the head disassembly. The lower will stay in the bike frame.

Photos to follow soon.
 

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dont be afraid of a little head work, especially if you got the right tools for the job.
before you start, get yourself a manual and a proper torque wrench, these are the most important tools that you will need.
then, go over the manual and try to understand what is needed for the head to come off... main things are oil passages, cam saddles and cam chain (tensioner and all).
in order to remove and reinstall the valves you will need a spring compressing arc, a device that will enable you to compress the spring valves and have access to the spring retainers.
mark everything and make sure everything is going back to its place.

for lapping, you will need some medium grade carborundum powder mixed with some engine oil to make a thick paste... if you have the sticks with the suction cups, it is much easier to lap the valves with it.
clean the combustion chamber up to a mirror finish, make sure you dont hurt the valve seats.
if you are at it, look into the intake passages, if there are any major casting imperfections or steps, go over them with a dremel tool (or any other grinding tool that will fit) and smooth it out.
it is a time consuming job, but not to hard nor complex.
have fun.
 

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I wouldn't try to lap valves that damaged, in fact, you're probably going to have to cut them off at the retainer groove and file them to make sure they don't tear up the guides on the way out.
He's right about that.

What you will have to do when the head is off is to remove teh valve springs and caps and before you try to remove the valves, see how much play there is at the stem. You probably won't need to measure it. Either there will be so little play that you can barely feel it or they will be loose. If they are really loose and move around, the guides also need to be changed but that is not very common.

Next thing to do it to take a file or dremmel with sanding disk and grind the top "corner" of the valves to remove the metal that's been hammered over like a mini mushroom. You will be replacing the valves, so it doesn't matter if you take off too much metal. The alternate is to cut through the valve in the middle of the keeper groove with the Dremmel and cut off wheel. The valves should then be a light finger pressure to push them out.

If the guides are OK, get a set of those Sirius valves and take the head and valve to an auto machine shop with a Serdi machine. They will cut the seats at a perfect angle and will test the seal between head and valve. You do NOT lap valves after they are Serdi cut. You just assemble the head.

I forgot one other step. With the valves out - before machining, wire brush all teh old carbon out and take pictures of things as you go.
 

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If you get the valve spring retainers off, wear some safety glasses. That way you don't get valve collets injuring your eyes when they fly off.

Get plenty of zip lock bags, and a marker pen. Organise everything like that. Make a piece of cardboard with holes in it, so you know which valve, came out of which valve guide. You can do the same with engine bolts and screws, if you like.

Don't even think of starting work without a good workshop manual for your exact model. A Clymer, maybe.

Leave the points and the timing plate in the points housing. That will make it far easier to time the ignition when it goes back together.

Lapping in worn out old valves, is basically a complete waste of time, most of the time. You need to get the guides checked, the valves cleaned and measured for wear, and the valve seats redone by a pro shop. The specs for the valve head measurements should be in a workshop manual.

I've worked in plenty of M/C cylinder head shops, so I know of what I speak.

Cover the open motor up with clean rags, like all the time. Dust junks engines fast.

Rav, I've worked on M/C cylinder heads for years. All nOOBs do is mess things up, and grind valve seats away so the installed height is all wrong, and too wide for good flow.

Danger, is my business.
 

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Discussion Starter · #6 ·
Thanks for the advice all! I've been marking all the bags and keeping parts organized already, so I'm off to a good start. Plugging up wholes as well (already have the exhaust ports plugged after removing the pipes.) I'll be sure to throw on the safety glasses.

As for valve lapping, I'd only be lapping new replacement valves. I'm not too confident that the left side damaged valves will be usable. Planning on replacing all 4 since I can't find any valve sets with both an exhaust and intake valve. Sorry for the confusion in that respect.
 

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lapping in brand new valves is also not a great idea, the seats really should be recut, it's not that expensive to have done, maybe $100 for the 360 head, definitely worth it as the seal will stay perfect for a very long time, lapping new valves to old seats might be okay for a few thousand miles but you're going to create a very subpar sealing and heat transfer surface, and shorten the life of your valves
 

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Discussion Starter · #8 · (Edited)
lapping in brand new valves is also not a great idea, the seats really should be recut, it's not that expensive to have done, maybe $100 for the 360 head, definitely worth it as the seal will stay perfect for a very long time, lapping new valves to old seats might be okay for a few thousand miles but you're going to create a very subpar sealing and heat transfer surface, and shorten the life of your valves
Lots of good points there... might have to go that route. What all would you hand over to the shop in that instance? Just the empty head and the new valves? And is recutting the seats necessary if the valve areas don't have any significant gouging/ scraping damage?
 

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ideally they wouldn't need the valves, assuming everything was cut at 45 degrees, they may want to have the valves so they can cut them as well to guarantee a match, but visual inspection isn't sufficient to assess a valve seat, can you detect .002" out of round with your eyes? let the people who do it for a living do it for you this time, you'll thank yourself when you have a reliable motorcycle you can enjoy
 

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New valves should not be cut or ground or lapped. The seat is coated and grinding removes that coating. All valve seats have some degree of pitting and cupping from normal use that needs to be removed. Seats have to be cut to a series of 3 or 5 angles to work properly. 3 are enough for a street motor. The best way is a shop with a Serdi machine. I hate places with Neway cutters and grinding stones. That's all so 1932 technology.

I have tried all of the above and have used up tubes/tubs of grinding paste over the years and Serdi is the only way to go - as long as I can get to one. We are lucky that there's an auto machine shop 10 minutes from here and their prices are fair. I still hate paying other people but have learned that a man has to know his limitations...... There are things I can do, some I should learn to do and others that I don't have the equipment to do (let alone the experience).

Any shop that does Imports can do your head. They need the new valves and the bare head - that's all. They can tell you if the guides are worn and can replace them if that's necessary.
 

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Discussion Starter · #11 · (Edited)
Guess I'll be looking for local machine shops then. Hopefully it's nothing too expensive. Should I assume that the springs should be swapped for new ones as well? Not sure if the guides are damaged yet either.

Edited- As luck would have it, a family member of mine can do the seat cutting for me.
 

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That's not necessarily good news - it all depends on what tools he has access to. If he has a Serdi machine, yes. If he is using stones or Neway type cutters, not so good IMHO. I should remember that we're talking a CB360 here and not a race bike, so maybe it will be OK. :)
 

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New valves should not be cut or ground or lapped. The seat is coated and grinding removes that coating.
I agree that the new OEM Honda valves should not be cut or ground, in fact it's not a good idea to regrind used Honda valves, but why no lapping on new valves? Use some Prussion blue to check the fit, and then fine paste. With a new valve and a freshly ground seat, it shouldn't be a problem as long as you don't over do it. Yes/no?
 

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I've used Serdis, Neways and old style stones. It's operator, not the tool. They all work fine.

Lapping in valves after Serdi or Neway jobs should not be necessary.

Find out the seat and valve seat width specs, from the right workshop manual, and grind the seats and valves to suit. Ask your family guy about those specs, if he gives you a dumb look, go get a pro to do it. ( even if he is a pro! ).

Danger, is my business.
 

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Discussion Starter · #15 ·
Great advice all around. Seems like there's a lot of scattered opinions about valve work. I'll check with my family member and my shop manual in regards to the seat cutting.

I'll attempt to get down to the valves this weekend and post up pictures. I know that's what's most important here. What's the life on valve springs though? I've read it's usually a necessary evil to swap them out when putting in new valves, but the bike only has a little over 7000 miles on her. Is there a standard mileage limit anyone goes by for swapping them out?
 

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Great advice all around. Seems like there's a lot of scattered opinions about valve work. I'll check with my family member and my shop manual in regards to the seat cutting.

I'll attempt to get down to the valves this weekend and post up pictures. I know that's what's most important here. What's the life on valve springs though? I've read it's usually a necessary evil to swap them out when putting in new valves, but the bike only has a little over 7000 miles on her. Is there a standard mileage limit anyone goes by for swapping them out?
You'll get lots of different opinions even from the guys who do it for a living. Most dealerships sublet cylinder head work, because it takes a high level of skill and expensive equipment to do it correctly. Find someone who does motorcycle heads if you can. Sometimes taking a motorcycle head to an automotive machine shop isn't the best course of action.
 

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I can't see there is any need to fit new springs at those miles. I don't know about the valve seal number or type, but they definitely need new ones.

Don't let the springs get rusty, and also valve springs have an "up" position. Mark the top of the springs when you remove them, with a white marker pen.

Danger, is my business.
 

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I've used Serdis, Neways and old style stones. It's operator, not the tool. They all work fine.

Lapping in valves after Serdi or Neway jobs should not be necessary.

Find out the seat and valve seat width specs, from the right workshop manual, and grind the seats and valves to suit. Ask your family guy about those specs, if he gives you a dumb look, go get a pro to do it. ( even if he is a pro! ).

Danger, is my business.
I'd be surprised if there are many decent shops using Neway cutters these days and there is probably a reason for that. Correct that valves "shouldn't" need lapping, but getting a perfect finish every time with hand held cutters is tedious work.
 

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I'd be surprised if there are many decent shops using Neway cutters these days and there is probably a reason for that. Correct that valves "shouldn't" need lapping, but getting a perfect finish every time with hand held cutters is tedious work.
Sharp Neways work just fine. Good Neways leave a minute surface finish that makes lapping-in redundant. Stones work better than Serdis for removing big amounts of seat material when installing new seats. All methods have their place in a head shop.

Nothing wrong with checking the actual valve sealing seat width using blue. I don't lap valves in, I usually give them a good hit with a small hammer and brass drift, in the middle of the valve head.

Danger, is my business.
 

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Great advice all around. Seems like there's a lot of scattered opinions about valve work. I'll check with my family member and my shop manual in regards to the seat cutting.

I'll attempt to get down to the valves this weekend and post up pictures. I know that's what's most important here. What's the life on valve springs though? I've read it's usually a necessary evil to swap them out when putting in new valves, but the bike only has a little over 7000 miles on her. Is there a standard mileage limit anyone goes by for swapping them out?
valve springs have a spec height. you can measure yours and see.
 
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