Topic: Question regarding cam tower cap markings 1 and 2 on CB750

[Wobbly]

I have a question regarding the marking on the cam tower/cam holder caps. They all have markings to match them up with the holder. However, I also see # 1 or #2 markings on top of them independent front the other markings which are combination of a letter and a number. Can someone enlighten me as to what these # 1 and # 2 markings mean, if anything, with regards to positioning the caps? The Honda Shop manual for the K7/F2 doesn't mention them at all. I am asking for a good reason, because--as you might have read in my other thread--I just toasted a new cam and new cam holder and four new rocker arms. If the aluminum got sheared off, it would explain how an oil passage got blocked, resulting in disaster. That is to say, perhaps the damage came before the oil starvation.
Your help is greatly appreciated.
Thanks,
Tom

[Wobbly]

I am still hoping to get an answer. Thus: bump.

[70CB750]

Picture?

[Wobbly]

I still have to take a pic of the caps, will do so, but it won't add anything. Basically, the four caps have, beside the side markings, either a #1 or a #2 marking on top.
I have seen several different cam towers, and there is no consistency in the way Honda has labeled them. My new replacements will be from the F2, "410" series. They replace all previous ones and have clear markings all over them--which is good. Some earlier ones have markings that are questionable. Others were more clear. All share the same part number.
I am just trying to figure out what went wrong with these ones, I bought new. But one of them is the culprit of my damage. That, I am sure off. I believe, I ended up with one wrong cap when I previously bought the holders new. I had three matches, which only left me with one that wasn't clear. Since there was no other place for it to go...All good and fine unless the wrong cap came with the new holder. The guy I bought it from on eBay, had a bunch of them. The newer ones now come from a NOS Honda parts dealer.

[70CB750]

Too bad my F3 engine (with 410 head) is all buttoned up now, I marked it all before taking the head apart and I could have matched factory markings to my marks - but as I said the engine is already in frame.

Could you verify caps/cam clearances and overall situation by some measurements?  Plastigauge maybe?  Just thinking aloud, there must be a way to peace of mind before final assembly.

[Wobbly]

Well, it's too late for me. I just toasted a new cam, new cam holder, and new rocker arms.
See:http://forums.sohc4.net/index.php?topic=135763.0
With the new 410 series cam holders, that won't happen. I probably replace, not just the toasted one, but both of the previous new cam holders (they cost a fortune).
I am just curious what these #1 and #2 markings meant, and if I was making a mistake there. The newer holders are labeled differently--no mistakes possible. And I had three matching side markings with only one cap left. So, unless the #1 and #2 markings dictate a position, I most likely ended up with a cap that didn't match the cam holder--not entirely my fault. The oil starvation I experienced resulted from the damage which must have caused the jet to be blocked. This, in turn, generated heat, which ruined the sealing puck, causing the massive oil spill. Sounds like a Sherlock Holmes type of story--but is the only explanation.

[Old Scrambler]

The little '1' on the tops may be a casting mark...........but it also could be an arrow pointing to the outside of each tower. The inscribed marks on the sides indicate placement with the marks to the outside (visible) to the end of each tower. They are usually marked with an X or Y and the letters 1,2,or 3. Each cap is machined at a slight angle at the exhaust-side to match the shape of the tower base.  Be sure to apply assembly lube and do not over-torque.   

[Wobbly]

Thanks Old Scrambler. I have actually seen all kinds of lettering and numbers. But I never had a set that was so vague and hard to make out--even with reading glasses. I have one unmarked side on one of the cam holders. Since all the other three checked out...and with only one left...
I bought this new on eBay. I have never heard of aftermarket sets, so I assume they are genuine--didn't waste a thought on that before disaster struck.
I cannot recall having seen the #1 and #2 markings before, but my memory might fail me and I am getting paranoid anyhow after this sobering experience. I was just wondering if the numbers dedicate the position as in #1 goes left, # 2 goes right--matching side markers provided. I was not digging deep yet, but did not find anything in the Honda manuals.
Unfortunately, I was too quick to get rid of my old parts to compare. And the newer 410 series is labelled differently--and better--than anything I have ever seen before.
Anyway, thanks everyone for your input.