Restoration of Sandcast #97

[Steve Swan]

KP, i will edit those differences on "88 Distinctions" per your measurements.

[kp]

Mark, i just noted what appears to be "the dot" (appearing faded red) on the RH side of your upper crankcase, pretty much directly accross from the vin pad.  It's interesting, seems, in past, members have noted some cases have these dots and others do not have dots.  the 2903/E3032 bike on ebay has same dot, only blue.  as i recall someone saying, these dots are only 2 different colors.........  someone, sometime ago, suggested the dot was for the body color designation the engine as to be fitted to................

none of the cases i have ever owned have ever had this dot or even a trace of having had a dot.  but i have seen the dots on engines i have not owned

anybody have a red dot on a believed original b-g machine or a blue dot on a believed original red machine ?

Also, KP, referring to the spacer in caliper, what do you mean by spacer ?  i have never heard about a spacer, but that does not mean anything.  Specifically, are you referring to "holder,caliper" pn 45115-300-030 ?  Are you saying there is an early and a late version of this part ?  (69.4 parts book)  My 3 other parts books, 71.2, K2 (print date unknown) and 74.1 all call for the same pn for the same part for vin #1 through end of K2.  Or, are you talking about a shim of sorts in addition to the "holder, caliper" ?  (Of course, we know the parts book is not an exhaustive reference source for these small differences made on the assembly line.)


232, 2157 and 4363 all came with what appeared to be the original caliper setup, but i did not notice differences in the caliper holder.  And i will admit, i was not looking for a difference.

I think I may be dreaming Steve. Given I play with Kawasaki Z1's I think it was the early Kawasaki that had a shim. I'll go look. It's just that the caliper bracket looked different in close up. I'm dreaming yes that's what it is  KP

[markb]

The 69/4 parts book shows a the typical Phillips fillister head screw fixing the ends of the 2 gauge rings together.  I don't know how i could debate the "8" bolt fixing your clamps together is not correct, but it is extraordinary to the convention of experience and literature. 

Actually I stated that the bolt holding the clamps together was a plain chrome hex bolt, no 8, but still different than the parts book.  So in a "correct" restoration does one go by the book or how it was found?

[Steve Swan]

sorry, i missed that.  My experience, any depictions or photos in manufacturer's manuals are not reliable for drawing conclusions as to originality.  The owners manual's descriptions of procedures is one thing, but pictures used to depict these procedures is another.  If you were restoring 97 using pictures from the owner's manual, we'd all go nuts, it's loaded with pics of the early pp bike.  The Parts Manual's sketches show certain parts known to be from the pp bikes.  Remember, Honda had to have these manuals avaliable at the same time the bikes were to be made available.  The only parts Honda had for artists to HAND DRAW their sketches for the parts book were likely some ofthe very first parts produced.

As i see it, this is why we cannot soley rely on the literature.  We must rely on each other for the observations we share to make the best assumption possible what may be correct parts.

To answer your question, Mark, i guess it would be nice if we heard from other members with these lower vins, but in order to hear from these members may require emailing them, to learn more.

We know the parts book shows a Philips head screw, not a hex head screw.  We are not yet aware other machines having a plain face hex head screw fixing the rings together.  All the picutres i have seen in all the literature i have, does not show any bike having a hex head screw holding the rings together.  It's hard to imagine Honda would use a hex head screw to fix those rings, if for no other reason than it would not look very nice.  But the hex head screw is present on your bike.  i guess th hex head could be used until the time it could be more clearly 'proven' a Phillips head was used.

Myself, i would probably use a Phillips head, as the hex head would make me a little nuttier than i already am.

BTW, your 6mm BOLTS holding the starter cover on.......  Are they flat head or acorn head ?  Andy Dixon's 175 came with acorn head NUTS fixing the starter cover and acorn nuts fixing the 6mm blinker body bolts to blinker stems.  When Andy removed his starter cover at last year's meet, there were 2 pieces of thread's all in the 6mm holes which the acorn NUTS attatched to.  As far as everyone knows, looking at the parts manual, acorn head BOLTS are depicted to fix cover to case.  Yamiya sells acorn head BOLTS.  I have a pair on 232, because i like 'em, but not because i believe they are correct.  I also have acorn head NUTS on the 6mm blinker stem bolts, because Andy's 175 has them, but there has been much discussion by several people (who i consider more knoweldgeable than my self) who suspected the bolts were added on by some proud owner after the bike left Japan.  O well, these issues with bolts are small details and can easily be changed out at any time.

[markb]

I got some answers, maybe.
 
My parts book is the 69/4.
 
I checked the bolts that came off the fender stays and they were 20mm long.  Should be 12mm according to the book.  I'm guessing they're replacements.

The hex head that held the rings together is a 5mm.  Not many of those (if any) used elsewhere.  Still could be a replacement though.

One other bolt I forgot to mention was the special hex head, phillips drive screw for the oil line to the crankcase.  All four bolts on 97 were big 8 hex bolts - no special.

I'll get a pic of the dot on the upper crankcase but mine is definately white.

Haven't got to the sprocket bolts yet.

Starter cover has hex bolts.

I measured the upper fork clamp and it is just under 20mm.  Obviously an early one.  Here's a pic of the "date stamp" on the bottom.  A little hard to see but is 3A.   Does that tranlate to January 68?

[Steve Swan]

The 4 bolts on the lower lines should all be "8" heads, no Phillips as on later machines.

[markb]

The 69/4 parts book calls out a special.  Do you know the cutoff number?

[markb]

The engine is out.


I know this is a sandcast but I didn’t expect to see sand in the exhaust ports.  I think ants or some other insects were living in it.  I saw webs and dirt with tunnels in the intake rubbers.


The 3 screws on the breather cap wouldn’t come out (using an impact driver) without rounding them out.  They’ve be soaking for a week but it obviously can’t get to the threads.  I had to resort to drilling off the heads.  I use a ¼” drill and stop when the head pops off.


Then the cover came right off.


Fifteen of the valve cover screws came right out but I had to drill the last three.  With a little tapping with a soft hammer the cover came off.  Note the cross-hatch pattern on the inside of the cover.  I’ve never seen that before.


Now the bad news.  The valve train is quite rusted.  A good place to stop for the day (last night).  I soaked everything up real good and will let it sit overnight.  Hmmm.  I might have to look for a donor engine.

[Steve Swan]

Mark, this is so VERY VERY VERY exciting !

Cross hatching inside the cam cover !!!!  wow !

I LOVE THOSE EXHAUST SPIGOTS WITH RELIEF !!!!

Chris and i suppositioned only the very first engines had that type of exh.spigot fitted.  As i recall, Andy Dixon's 175 does not have these relief type spigots fitted.

Whew.  the engine is a rusty .  must have sat outside for a long long time.   i know you will go slow.  there will be guys who can offer parts to replace what is rusted beyond usefulness

i can't answer on the screw, the parts book calling for a special.  i am sure my memory serves me correct, there were no phillips screw holding lines on to case.  but, i may be remembering wrong.  i will look at 232, as the screws that are fixing lines are the screws which came with the bike.........

we need Chris Rushton on board.  i've emailed him to weigh in

[hondasan]

Hi Mark,

Very interesting stuff - making your project public via the BB has got some great discussion going. MORE OF IT PLEASE FROM MORE MEMBERS.

A number of comments to make...
A couple of misquotes have occurred re. my #302/E338....
Mirrors - it came with only one mirror, that being an 11mm stem one. I have no reason not to assume the other mirror would also of been an 11mm stem one.
Oil lines - BOTH are the early plain, no fabric covering type on E338. (I previously owned #1256 / E665, a correct factory pair, which had one plain line and one favbric covered line).

Also, all four lower oil line bolts were number 8 bolts - no "special" as per the parts list.

That valve cover is pretty neat, never seen one of those before.

Good to know the early relieved exhaust spigots went at least 100 into production  -only previously seen those on a pre-production bike and engine #5.

A comment was made regarding use of replacement fork tubes, ie, should they be used if they are repro's and fully chromed / carry a manufacturer's logo (where it can't be seen) DOES IT REALLY MATTER?! for an item like this which cannot be seen. Sure if NOS was available, that would be the way to go, but they can't be seen anyway. 
Many of us are glad to be able to fit Yamiya no number exhaust pipes, which are about as visible as it gets (and not actually 100% accurate detail wise...!) , so why not repro fork tubes of known to be great quality that you can't see anyway.

Restoration is all about compromise, and lets not kid ourselves - no restored bike is going to be 100% factory correct unless we can find every part NOS made at the same time as the factory made the original parts for production. Oh, we also need to fill the tubes with japanese air too!

Couple of other items...
You should find that the 6mm bolt at the rear of the cylinder head is a "special" (not a #8), same as the four under the sealing caps beneath the cam carriers.

Short ferrule cables - it is possible to shorten the  ferrule on the later cables to achieve the correct "look" - if I can figure out how to post apiture, I wll do so later.

Keep at it - brilliant so far - Chris R

[Steve Swan]

Thanks Chris, for clarification on the details of your 302 ! 

I use my lathe to shorten the ring nuts on the tach/speedo cables.  My procedure works perfectly.

[markb]

The cam, rockers arms and cam holders are off.  I cut the cam chain so I could rotate the cam.  It’s going to get replaced anyway.  Hardest part was getting the 1-2 holder off.  I tapped on it for an hour.  I think it was more hung up in the stud holes than the knock pins.  Believe it or not I had one of the cam holder bolts snap off.  After I got the holder off it turned out with my fingers.


There is one bit of bad news though.  I discovered a crack in the 3-4 holder.  I’m thinking it might have happened when I tapped the rocker pins out.  They moved but they moved slow.  It might have been there before too.  Who knows.


Other than that, things didn’t look as bad as I thought they would.  Here’s the cam.


Closup on the cam lobes.  


And the rocker arms.  No rust on the working parts.


Then came the head.  I took off the rubber pucks (just might have to replace them) and took out the four special screws below them first (for those who don’t know always do these first).  They came right out.  At first I thought my socket wasn’t engaged because there was no resistance, on all four.  My guess is the PO tightened them first and then the main nuts and that’s why they were loose.  By the way, only one of the four had a Phillips drive.  Then I did the nuts in reverse tightening order and the special bolt on the rear side.  The head pulled right off.  Note the interesting stud layout for the cam holders.

 
The head looks pretty good too.


Closer look


Even the cylinders didn’t look to bad.  I got her soaking now.  I’ll pull of the rotor cover next and see if I can turn it over in a couple of days.  Maybe I won’t need a donor engine.

[hondasan]

Shame about the crack in the holder, it being an early sandcast one. No doubt repairable though.

Looks like the head has been off previously judging by the later headgasket with hole at the front of the can chain tunnel, and orange sealing rings at the 8 studs which oil drains down, so maybe someone else is responsible for the crack?

Chris R.

[markb]

There is plenty of evidence that this engine has been open before.  I could blame the PO for the crack but I won't  I've got access to a machine shop so I'm thinking of trying to repair it.
Mark

[kp]

Mark, Wow! This is interesting stuff and probably one of the most interesting posted on the board for some time.
Can I make one wee suggestion. When undoing these very old nuts, bolts and parts, use a butane torch or better still, MAP gas to heat the area up first. Get the areas very hot and let it cool down. This generally breaks the bond between the two surfaces. If not then repeat the process. you will generally save the part breaking and save much time and effort. Aero Kroil as Steve suggested will actually work into the areas more efficiently with a little heat. My engineering mate told me this one and he makes some of his lliving from unsiezing seized part.
Keep the photos and story coming, as this is great
Thanks again Mark