Topic: What do you think? Revise, rewrite, or supplement?

[HondaMan]

Since I wrote 'My CB750 Book' (2009) there have been some developments in the gasket world that cause troubles when assembling these bikes, all of them, and especially the CB750. The problems centered first around the incorrect head seal pucks we all suffered from the sellers, and later (until the present) the head-gasket leaks, caused by too-thick head gaskets (caused by the outlawing of asbestos, another topic...) that prevent the oil passage O-rings from sealing unless you use thicker O-rings there (which don't come in ANY kits). So, I am considering either/or:

1. Revising the original manuscript to show use of thicker O-rings at the oil passages, and where to find them
or
2. adding a section (which will throw off ALL the page-number references after that!) to show how this has come into being, because it affects all of these bikes, even the Twins and Singles
or
3. making a Supplement book (probably 10-12 pages, almost a pamphlet) to tell everyone how to prevent their vintage bikes from leaking, and how to check them against the gasket kits we get today.

Any feedback or ideas are welcome: I can't keep up anymore with the almost 100 e-mails per month I am getting about these leaking heads, and they ALL have the very same cause - the modern head gasket (100% of EVERY TYPE MADE) are too thick, with the MLS being the worst of the bunch. They are all 1.00 to 1.2mm thick, where the engines were designed to take 0.80-0.82mm thick head gaskets, so the oil passages through the heads are not sealed by the standard-thickness O-rings found in ALL gasket kits today. they must be changed out for thicker O-rings or rubber seals to make up the head-gasket thickness difference, or the head WILL leak oil pressure. That's the crux of the issue.

[Marks78]

Just some thoughts -- A supplement book/pamphlet would be nice for those of us that already have your book but a revision would be nice for future printings of your book. A pamphlet could be included in future copies while offering it for sale as a stand alone purchase for those who wanted just the pamphlet.
Thanks for caring enough to want to keep the information current and available! I use your book almost every time I work on my 750K8.

[01Thomas]

Hi
I also think a suplement is the way to go.

regards
Thomas

[jamesw]

I'll third the supplement idea, as well as the suggestion of where to buy the appropriate o rings, gaskets etc.

I know one of my two bikes has an MLS head gasket that I got from cycle x. Faaaack.

[IVPeters]

Rats, my build has the MLS from CycleX - I didn't have any leaks during the break-in last year but I imagine it may only be a matter of time.
I remember buying Hi-temp silicone o-rings specifically for the cylinder/head mating (orange ones in the pic), but I'd have to check where I got them and what size they were spec'ed.
I like the idea of the Supplement book.

*Edit - I used 11 x 2.5mm from here: http://www.oringsandmore.com/silicone-o-rings-11-x-2-5mm-price-for-10-pcs/

[HondaMan]

I've been trying to think of a way to 'reword' the section in the existing book to update it, but it has to happen without changing page numbers or adding pages. The 268-page edition that it is was just 2 pages from being $5 more(!), and it is already expensive IMHO. (I'm a cheapskate...).

The MLS gasket delays the onset of the leaking, but won't stop it, because it seals to the faces of the head/cylinder better than the others. But, it is also thicker in the ones I have seen, leading to a worse leak after the pressure delaminates the gasket. Sometimes it even lets it wick into the cylinders, so some poor owners have thought they had broken rings, or the like. It makes me so sad...all that work!

When you install these O-rings, use at least the Parker 2.62 x 10.77mm (aka 7/64 x 27/64 inch) size, or a 3x11 or so if you are not using the HD studs. IF the head gasket is more than 1.15mm thick (un-squished) then you MUST use the 3.00 mm thick version, and it also won't overly restrict the passages when tightened.

[Stev-o]

 A supplement book/pamphlet would be nice for those of us that already have your book

+1.  Seems like all my bikes leak oil, hate that!

[MoMo]

small supplement seems the best way to go Mark...Larry

[IVPeters]

I've been trying to think of a way to 'reword' the section in the existing book to update it, but it has to happen without changing page numbers or adding pages. The 268-page edition that it is was just 2 pages from being $5 more(!), and it is already expensive IMHO. (I'm a cheapskate...).

You've got some decent white space on Page IC-26 - It's the correct chapter too. *shrug*

[Frank Rodgers]

The supplement is a great idea. For future editions the supplement notes might only affect chapters 1 and 2. Great reference book and thanks for all your work.

About being a cheapskate you should live in Canada and buy stuff for your bike from the US.
$1 US costs $1.35 CDN plus import duties and sales taxes. Adds at least 50% to the cost.

[PeWe]

Good idea with information about head gaskets and o-rings.
I add some  I have experienced with my K6 that I had rebuilt some times the last years

Maybe some info about MLS (Multi Layer Steel) for head gasket and RCS (Rubber Coated Steel) for base gasket as well?
I currently use both in my K6 with 71.25mm pistons. Bone dry after 6500 km.
It is very important that the surfaces are flat and scratch free.

I sanded head and 836 cylinder on a thick flat board with glued sanding paper on. 3-4 rounds of grit 240 to remove all scratches and old machining marks. When OK, 2-3 rounds of grit 400.
That did not leak. I used the 2 o-rings on oil support despite the MLS has sealing ridges for them.

Later with Billet block that had perfect surface.
I sanded the upper case in the same way, I saw Honda machining marks revealed after a little sanding. Some rounds with grit 240 followed by grit 400

One more detail about MLS. It has rivets that can interfere with mating surfaces. It did on my K6 head with K6 cylinder. I hammered the rivets flat and upon that drilled small dents in both surfaces where the rivets are, head and cylinder. 8-9mm drill that drilled just a little making a dent, not a hole.

The later CB750 gaskets for earlier heads and cylinders need + 8 o-rings where the oil returns hole are, right?
These o-rings need to be revised then?
I have ordered most of the o-rings in Viton which feels harder and more plastic than Honda's and aftermarket gasket kits that must be Nitrile and do not withstand the high temp the head can get. I have read about max 110-120C. My oil in tank has that temp.

I had before I installed MLS severe head leaks when I coated a Comet fiber gasket with copper spray. Bad idea! I heard from my local tuner that that a graphite gasket must be mounted dry. Additional sealer on any gasket is not needed in my engine (except under rubber coins under the cam holders. I reused them in the 80's that worked fine with add sealer). It cause more problems as I have seen. If any of the covers has deep scratches, sand it flat on a thick board with glued sanding paper on, grit 240 followed by 400 as final.
Honda light green fiber gaskets much better than any of the gasket kits I have tried, except Yamiya that has good blue gaskets in its kit. Some kits have gasket with poor fitment, holes do not match, valve cover gasket has wrong shape on exhaust side between 2-3 and the bolt tighten valve cover can hit gasket which will be teared off when tighten it. Gasket need to be cut to stay free from cam tower for 2 ex side or maybe 3 too. Honda  gasket fits like a glove.

[AwesomeCB]

Looking at this as a former editor (30-plus years in magazines, newspapers, corp comm), I would suggest adding the new material and restructuring the book's layout and flow to accommodate it. It would also be a good opportunity to enhance the book for layout, readability, ease of finding materials, logic, structure and other content like better graphics.

Add the new material, tout up the "new, better, revised version" and use that as an opportunity to boost sales. Marketing 101.

[Sapphireminer]

Hi Mark I think option 3 the supplement  would be good as current book owners would be able to purchase it and new buyers could have it included with thier book order no messing with the book thanks for all your good work.
Dave

[PeWe]

Breathers sucks! Not enough by Honda.
One more thing that affect oil weep/leak between cases. Over pressure due to weak breathers.
My engine wept oil between the cases after some high speed touring in the 80s, 836cc. I blamed the blue Hylomar.
I got some drastically more weeping cases (mostly thru Oil filter cover o-ring) after going bigger with 1000cc.
Got the good how to do after have seen a mod (Video of MRieck's bike start this year) installed an extra breather hose connected to the clutch cover. It helps!
I'm sure this should have avoided the old weeping cases back in the 80's.

[Erny]

Mark,
I suggest for supplement & if possible, I'd like to have description of differences that K7 & K8 has against pre K7 models.
Especially details about carbs tuning and other improvements specific to K7

And many thanks for your book, very helpful!

[piefairy]

You could add a notice on the affected sections and reference an index or update at the end of the book covering the issues. I'm not sure how many pages you would need to cover it. Otherwise, you could note a web link to cover the addendum for the current time, because as I'm sure you are well aware, more will arise in the future.

I'm not against the supplement, but I am not sure on the cost/return value. On the website, you could always require the proof of purchase, or PO#, from LULU to access it.

[The Lone Builder]

Whilst I think the cost of the 1st edition was high - we're all cheapskates at heart, I also think, as an amateur and inexperienced renovator, it was definitely worth it. The quantity and quailty of information was excellent.

That said, I would definitely hesitate about paying the same, or slightly higher amount, for a 2nd edition with only a small amount of additional material. This would hold even if all the "improvements" suggested below were included.

Looking at this as a former editor (30-plus years in magazines, newspapers, corp comm), I would suggest adding the new material and restructuring the book's layout and flow to accommodate it. It would also be a good opportunity to enhance the book for layout, readability, ease of finding materials, logic, structure and other content like better graphics.

Add the new material, tout up the "new, better, revised version" and use that as an opportunity to boost sales. Marketing 101.

I'd vote for the supplement, at a fee if you think this is appropriate; and why not?

Sean

[kixbox]

+1 for supplement.


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[HondaMan]

These are all great hints and helps.

I get many questions about the differences between the early and late bikes: certainly the "F" bikes need almost a book of their own if all the differences were to be covered in the brakes, suspension, wiring, clutch, carbs, wheels, pipes, cosmetic issues, and the like. But, the changes inside the engines, where most of the issues arise, were not that great and can be covered in about 3 pages of text and pix, so I am not sure that a whole book or 50-page supplement is actually required for them?

But, as pointed out by PeWe and [many, many] others, the oil leakage issues, and lately the 'new' gasoline issues here in the USA, HAVE become a biggie in the last 6-7 years. Since there is no direct "go buy Brand X" solution to it, but rather a handful of 'measure this and do that accordingly' solutions to it, this is what has me thinking about this add-on version. I'd like to outline the 'how to' methods of discovering/resolving the problem areas while the engines are being assembled, in a step-by-step approach for the uninitiated who wander into the fun-land of these bikes.

I am just now embarking on the 500/550 book, which will likely take until Spring to get it all together, but this supplement (or whatever) will be the next one behind it. Any other ideas, please chime in! Each copy returns at least $1 to this forum for its support, and I get a few $ on each one, too, although that wasn't (and still isn't) the big idea behind writing it: these bikes have just been part of my life for almost all of it, and lately it seems to have become bigger than it ever was(!). I get to meet the nicest people [while working] on these Hondas.

[Don R]

 I'd buy an pamphlet or supplement. On my K4 motor 836 with an mls gasket I tried auto AC o rings which seemed too thick so I used a steel shim and a double edged razor blade to cut down some of the tall seals. I don't know if it's OK because I haven't put many miles on it. Too many other bikes and this one was always on the lift.

[HondaMan]

I've been trying to think of a way to 'reword' the section in the existing book to update it, but it has to happen without changing page numbers or adding pages. The 268-page edition that it is was just 2 pages from being $5 more(!), and it is already expensive IMHO. (I'm a cheapskate...).

You've got some decent white space on Page IC-26 - It's the correct chapter too. *shrug*

That might be a good idea for a 'revised edition' version: squeeze in the Critical Updates on that page?

[HondaMan]

I'd buy an pamphlet or supplement. On my K4 motor 836 with an mls gasket I tried auto AC o rings which seemed too thick so I used a steel shim and a double edged razor blade to cut down some of the tall seals. I don't know if it's OK because I haven't put many miles on it. Too many other bikes and this one was always on the lift.

Many times, the owners think the leak is coming from those long rubber dowel seals at the front: it is not. It is leaking out the front because of gravity: the oil is actually coming from the oil passages at the back,washing under the bottom side of the head gasket, dribbling to the front. This is part of why it is so hard to explain... 

[IVPeters]

That might be a good idea for a 'revised edition' version: squeeze in the Critical Updates on that page?

Yeah, like an addendum at the end of the chapter.

[MauiK3]

First, I feel the book (I got hard cover) is like all tools, good ones cost more and your time and dedication is priceless. The book is the most important tool I had while restoring my K3. Thank you again for your efforts.
The supplement seems to be the most efficient way to get this vital information out. I have not seen any leaks yet but if I do I’ll know what to do if I have the right information.
Thank you

[Patrick]

Hi Mark, I suggest you do an addendum to add to the back of the book. Unless and until you are ready to revise the entire manuscript for a reprint, then just add a section with updates.

Patrick