Cylinder Head Puzzled

grubsie · #1 08-14-2012, 06:07 PM

I am right smack dab in the middle of tearing down the "Early" 1963 CA95 that I acquired last summer and just got around to now. The one piece that I am curious about is the cylinder head. Especially the right side. Instead of just the cap, it has a tach attachment with the extended cam with worm gear. It also has NGK C7HSA spark plugs that are a narrower thread diameter (10mm) than typicalD8ha (12MM) Plugs. A saerch at NGK shows the 10mm for earlies and 12mm foe lates. Even though the tach is on there, there is only a slight notch in the fin to allow for clearance. There isn't enough clearance of the fin to allow a cable to fit it. Is this the correct head for this "Early" Ca95. Should I use it or change to a different head? Funny thing is...it ran very good with this head. I know that there were 2 versions in '63. An early and late. Most recognizable buy the upper rear shock supports and early flat sided mufflers vs late round mufflers.

I have attached a pictures of the head.

I found this site that shows the tach on an early 1963 here. http://www.cyclechaos.com/wiki/File:Honda_Ca95early.jpg

On another note..Does anyone know a good source to get assorted Phillips case screws used on these old bikes? Several of the screws on this motor are pretty buttered up (Stripped heads) and won't exactly look good on the restore. I have been searching the web everywhere with no luck.

Spokes · #2 08-14-2012, 07:10 PM

The cylinder head is an early model. If the engine ran fine with this head, I would use it. Finding an original tachometer for your bike is tough and expensive. I have only seen one for sale that sold for better than $500.00. My point is not to worry about clearance for a cable unless you have the tach. I would think the fin could be machined to allow for clearance. I hope that member "Sam" chimes in as he is expert regarding this early part.

PM me with what you may need regarding original screws. I have many sizes from past rebuilds. I use new chrome or stainless screws, but keep all good original screws. They will all need to be zinc plated if you want that original look.

Sam Green · #3 08-15-2012, 02:55 PM

It's a bodge up.
The head is an early 125cc C92 with out the cut away for the cable.
The end of the rev counter drive has been cut off as has the bearing that is on the back side of the rev counter drive that is not shown.
This cam and rev counter drive should not be used on this head as the oiling system is all wrong for it.
Take a picture of the combustion chambers, there will be no squish band for the bigger 150 pistons causing them to hit the head, that is unless it is a complete 125 top end.

Sam.

grubsie · #4 08-16-2012, 04:45 PM

Sam,
You are absolutely correct. I checked the combustion side of the head there is no squish band. I compared it to an existing CA95 head and noticed the difference. I bow my CA95 front end to you.
Question now is how rare is the c92 head I have with the tach cap?
I have attached a picture of the combustion side.

Spokes,
I inquired about the phillips head screws because of the stripped phillips ends I have and there is a bunch of them (all sizes) that I need for this bike and a CA160 I picked up last week. (My next project). I looked at stainless screws but the heads are larger in diameter and flatter looking than the the stock screws and they also won't fit correctly due to the larger diameter head. I would welcome any screws that you have available. I was hoping to find a source for the stock type screws somewhere so I could buy bunches of them. I appreciate your help.

Spokes · #5 08-16-2012, 05:03 PM

PM me with an address and I will send most of what I have. Some of them will be off color as I was cleaning them up. They are just taking room in my shop anyway.

Larzfromarz · #6 08-21-2012, 12:11 PM

I basically decided to change out everything to allen head screws either socket or button head. Ultimately it relieves the probability buggering up Phillips type screws. I believe you get better torque control as well. I have purchased several "kits" off of eBay and i pilfer screws from these kits when I need a "factory" looking fastener. Admittedly the kits were for single cylinder Hondas but found that most screws can be used somewhere on the twins. Be careful of JIS screws as most suppliers don't have that clue. I use a local bolt supplier with good results. I'd steer you to the aircraft industry but they use SAE threads.

Sam Green · #7 08-24-2012, 12:41 PM

Well I posted a reply a few days ago but it seems to have vanished, perhaps I only thought I posted.

The head is defo early C92, RARE? they are 10 a penny world wide but not in the States.
From the pic of the combustion chambers, it looks to have had a squish band machined into it.
The rev counter drive is toast as it has had the threaded top cut off where the cap screws on, I'm guessing it must be plugged with something. It would have made sense to cut the head away instead, doing it that way would let you use the rev counter.
Before anyone tries to do this mod on a late model head, a return hole has to be drilled to let surplus oil from the bearing back into the head, otherwise it gets pumped up the tach cable and into the tach.

Sam.