Topic: Time to pull my head and fit the replacement, first time. Seeking advice.

[strangedaze39]

   So my head was cracked near port 4 and isn't sturdy enough for my to feel safe riding the bike long distances. I ended up purchasing a head from ebay thats in very nice condition and from the same year/model as my bike (72 CB350F).

I plan on pulling my head and replacing it with the one I just bought and some new gaskets, the one I bought has all the valves and springs in it and beside the valves look carbon filled they look and seem to function fine. A couple options I can think of.

A) Just use the head casing and switch all of my valves/springs etc. over.

B) Use the new head with the valves/springs it has in there right now.

Couple of basic questions:

1. What is involved in swapping a head? Do I need to pull the entire engine?

2. Besides the obvious what needs to be done, I suspect I cant just bolt it on there and everything' is hunky dory. Cam? Timing chain?

Any resources or help is wanted. Thanks for taking to time to read this.

[Gordon]

As long as there's not signs of excessive wear on any of the parts of the new head, I'd leave the valves/etc where they are and use it as a whole piece.  

You don't need to pull the engine to remove the head on any of the sohc4's except for the 750.  As far as specifics of what needs to be done to remove and reinstall the head, that will all be detailed in your manual.  If you don't have one, get one before you start.  

I highly suggest replacing the cylinder base gasket, too.  The process of removing the head will often break the seal of the base gasket and can cause a leak if you don't replace it, and who wants to go through the whole procedure again just because of something like that?  This will also give you a chance to inspect your pistons and rings to make sure they're in good shape and still within spec.

And no, you don't have to replace the rings just because you removed the cylinders.  Measure the end gap, and as long as they're still in spec it's fine to continue using them.

[strangedaze39]

Thanks Gordon, that advice will be extremely helpful.

I think I'll order the gaskets now (top and bottom) to be safe.

I'll let you know.
-Cody

[Gordon]

Get the whole top end gasket set, not just the head and base gaskets. 

[75750SS]

I like de-carbon the heads, valves and pistons when I have the opportunity.  I also lapped the valves the last time and did see an improvement in compression.
It gives me an excuse to buy more tools, but that's just me.

[Gordon]

It gives me an excuse to buy more tools, but that's just me.

I love a good excuse to buy new tools!!

[manjisann]

Is lapping valves hard? If I understand the basics right, you use a lapping compound between the valve and head and a lapping tool (suction cup on a stick ?) to spin them around till both pieces are uniformly shiney?

Thanks,

Brandon

[75750SS]

Lapping is easy.  I found sitting down with the heads in my lap over thick towel, I could watch TV at the same time.

[manjisann]

Insert Quote
Lapping is easy.  I found sitting down with the heads in my lap over thick towel, I could watch TV at the same time

Hehe, quality time with the motorcycle 

Brandon

[strangedaze39]

Can anybody recommend a good place to pick up a gasket set? Maybe from a place you've bought one before?

@75750SS: I'd love to hear a more elaborate description on how you decarbon and lap your valves. I should definitely give that a go.

Thanks for the responses 

[fmctm1sw]

Can anybody recommend a good place to pick up a gasket set? Maybe from a place you've bought one before?
Thanks for the responses 

I bought a set off a guy listed as "Cycle Parts of Lubbock" (CPOL something) on eBay.  I picked up a base gasket for like $1.00 a while back.  And check out the great deal on side covers.  Ratty covers for only $100 buy it now!   

Lapping is easy.  I found sitting down with the heads in my lap over thick towel, I could watch TV at the same time.

I use my drill and a piece of small diameter hose.  Forward and reverse.  Just make sure you don't pull too aggressively.  I bought my lapping compound at Autozone...

[strangedaze39]

Thanks fmctm1sw, I just borrowed a lapping stick (or w/e they're called), and a very very basic valve remover which isn't going to work at all.


FYI if anyone is looking for full gasket kits for their bike call Cycle Recycle! They are awesome, the site stated out of stock but I called and I got a complete athena gasket set for $30.00 and shipping was something like $6 for my entire order (including handle bars and misc other items).  I'm sure they carry other full gasket kits for just about every other 70's CB as well. Mine was for a CB350F.

Anyone know how I should go about pulling the valves, the tool I have now doesn't look like it's going to work.

Edit: NVM on the tool. Ended up making my own tool to remove it, couldn't have turned out any nicer and it was extremely easy to make. I will post some pics up soon and a little how to.

[fmctm1sw]

FYI if anyone is looking for full gasket kits for their bike call Cycle Recycle! They are awesome, the site stated out of stock but I called and I got a complete athena gasket set for $30.00 and shipping was something like $6 for my entire order (including handle bars and misc other items).  I'm sure they carry other full gasket kits for just about every other 70's CB as well. Mine was for a CB350F.

Anyone know how I should go about pulling the valves, the tool I have now doesn't look like it's going to work.

Edit: NVM on the tool. Ended up making my own tool to remove it, couldn't have turned out any nicer and it was extremely easy to make. I will post some pics up soon and a little how to.

Wow.  I may look them up.  Let me see your valve tool.  I fashioned one myself as well but it slips off every now and again.  I have a overhead valve removal tool I bought at Sears.  It works on the intake (or is it exhaust?) but won't fit on the other side.

[moham]

I don't know about the 350s but for my 550 the Sears valve spring compressor was no go. I recommend highly the Sporting for Less tool with varied size adaptors and extra wide/tall jaws. Was night and day from the other tools I used.

Good luck, read the manual and take your time...

[Glenn Stauffer]

Anyone know how I should go about pulling the valves, the tool I have now doesn't look like it's going to work.

Edit: NVM on the tool. Ended up making my own tool to remove it, couldn't have turned out any nicer and it was extremely easy to make. I will post some pics up soon and a little how to.

When I did this on my CB550, I was given a home made tool by a mechanic friend.  It is a sparkplug socket with a window cut into the side big enough to get at the valve keepers.  I'm interesting in seeing the tool you made.