Restoration of Sandcast #97

[Wayne]

Nice work Mark. We have been waiting to see this engine come together. 

[markb]

Thanks guys.

Here’s a follow up on the puller I made for the cam chain tensioner.  I was looking on the Yamiya site and stumbled across this.  They have one although it is different than mine.  It is another way to do it.  Unfortunately they can only sell it in Japan (why is that?).  I thought it was interesting that someone else had already done it. 

[4pots1969]

Mark,
A small detail which saddens me a little on such a restoration...  Why to have put the horrible green gaskets of recent manufacturing while we can easily find and buy any first gaskets of origin corresponding to Sandcast which were of black color?
Just an observation...
Gerard

[4pots1969]

I tried to order the tool on their site and the order is not blocked when I confirm the delivery for France??

[markb]

  Gerard, excellent point.  I wish you would have brought it up sooner.
Seriously it never dawned on me.  I can't believe I didn't think about.    I agree they should be black.  Believe it or not I'm almost considering changing them.

Interesting about the Yamiya order.  I just checked again and it's listed as Japan only but maybe they will ship anyway.  There was something I would have liked to order a while back but I didn't try because it was listed as Japan only.  Next time I will try.

[markb]

Below are pictures of spark advancers that I have taken out of my sandcast engines.  The left one is from E100.  The right one is like I have from three later sandcasts.  Note that the E100 one has slots and that the tabs are centered and the weights are heavier than the one on the right.  I had read that the early sandcast advancer was from a 450 and had slots.  I don’t think I’m going to be able to save the E100 one so I checked on ebay and found some early 450 ones with slots but the tabs are off center and the weights are lighter.  I also learned that K3-K4 advancers have the heavier weights with the centered tabs like E100.  It almost seems like E100 is some kind of hybrid assembly.  What I’m trying to find out is if what I have on E100 is correct.  Does anyone have pictures of the early advancers that they could share?

By the way I had a slight panic attack thinking that the timing marks might be different between the two advancers and that my cam sprocket timing might be wrong but I checked and they’re both the same.

[greggo325]

371's doesn't have the slotted advance plate. 

[markb]

Are the tabs centered like on the left or offset like on the right?

[Steve Swan]

371's doesn't have the slotted advance plate. 

is this slotted advance unique to low vins..... ?  appears to be......... ?

[markb]

Maybe, but the strange thing is the research I've done doesn't show the centered tabs and heavier weights until the K3's.  Anyone have a low (lower) engine number with pics of the advancer?

[4pots1969]

Markb,
I have a severe doubt that your Spark Advance is the one of origin for your E-100 and I think that it was changed because I have it a which looks like curiously has your among whom here is photos it is K3 1972 >> F2 1978...

http://www.cmsnl.com/honda-cb750f-750-super-sport-1978-usa_model7240/advancer-spark_30220300154/

[markb]

I'm pretty close to deciding the same thing.  I'm going to try to clean mine up so that I can read the markings.  If it has TEC on it (I read somewhere that they started making them for the K3's and later) I think for sure it is a later unit.  Also if there is not a 450 stamped on it then it would most likely be a later unit.  Some of the 450 ones that I saw had 450 stamped on them.  That would be fine then I wouldn't have to worry about saving it.

[kmb69]

Mark,

Sorry, I have not had time to check and post until now. But I think the E100 advancer IS ORIGINAL. Why you ask? Because it appears identical (except for the oxidation) to my V33 E69!!!

I will check some of my other low VINs and post as soon as I have time. Probably be after the Holidays.

Keith

[Erling]

Spark advancer. Got in the day a workshop manual together with my CB750.
On page 84 a picture to illustrate what is an advancer. Looks quite different to the two.
But next picture where it is in position on motor the advancer looks like the one to the right!
    Erling.

[markb]

I soaked the advancer in Safest Rust Remover and I was able to clean it up enough to read the markings.  Besides the timing marks there is a TEC logo on one side…


….and a 300 with an arrow on the other side.


So it’s definitely not a 450 advancer.  I looked in parts manuals and this shape with the slots shows up in the 1975 and later K and F models.  I also looked in early parts manuals and shop manuals and they have the same shape as my later sandcast ones.  Keith, I don’t doubt that yours has this same shape but I don’t think mine is original.  Can you take a picture of yours that shows the markings?