Honda CB750 Sandcast

Oil filter cover

chrisnoel · 63 · 30434

Steve Swan

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Some of the finned covers do not have internal ribbing, so they are the best candidate for modificaton.  The fins can be easily removed, i have a modified cover waiting to go on the unstamped engine for 2157.


markb

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Oil filter cover with ribs inside and the fins inside turned off just sold for $150.00 on FleaBay.  Gee's, if people are willing to pay that much for incorrect forgeries I should use duct tape to make a recessed lip on an ignition and see what I get for it.  
Just curious, how do you know it's a forgery?  Didn't the later smoth oil covers have ribs inside?
Mark
Some of the finned covers do not have internal ribbing, so they are the best candidate for modificaton.  The fins can be easily removed, i have a modified cover waiting to go on the unstamped engine for 2157.
Ahh, some finned covers had no ribs but the smooth covers never had ribs.  Steve, I just read your post in the scammers section so I get it now.  Thanks for the education guys.
Mark
« Last Edit: April 21, 2010, 03:13:35 pm by mark1b »
Mark B
1969 CB750 sandcast #97 restored - Sold Restoration thread link
1969 CB750 sandcaxt #576 - Sold
1969 CB750 sandcast #1553 - Sold
1969 CB750 sandcast #1990 - Sold
1969 CB750 sandcast #5383 restored - Sold Restoration thread link
1970 CB750 K0 restored - Sold
2010 H-D Tri Glide Ultra Classic (Huh?)


vnz00

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Hi all, I thought I might add a little more to this thread.
I spoke to the previous owner of one of my late (7109) sandcasts. He was also the original owner purchasing it new, Jan 70.

He stated that the oil filter cover he purchased the bike with was not a round, but rather a finned version.  Looks like the dealership replaced the part when the service bulletin was issued, or possibly, they were replaced at the factory itself.

I have noted that Steve Swan stated the service bulletin recalling the round oil filter covers was issued Jan 1970. But it stated the 010 part number, finned, internally ribbed, number 2 cast on it.  So somewhere before that the finned, internally ribbed versions were being produced and supplied to either dealers or fitted in factory.

The same service bulletin also mentions 12mm bolts issued to replace the 14mm bolts to hold the filter covers on.

So it looks like Honda must have done a run of finned, no internal rib covers before issuing the service bulletin. These may have been used at the factory or in dealerships prior to the SB being issued.  I say this because 5528 came with a finned, unreinforced cover, with 14mm bolt. It also had #28 caps indicating it may not have been subject to factory recall. Or if it was, it was prior to the SB as it did not have the 12mm bolt.

1853 has the same cover, but a 12mm bolt. The carb caps were the later type, hence it went through factory recall of these items, but the dealership was supplied with finned, unreinforced covers.

I can't check 7109 as it is with a pal in the USA.  But I'm curious to know if it has a 12 or 14 bolt from when it came from the dealership new.

A few members have later sandcasts with finned, unreinforced covers. If they could fill us in with what size bolts, it might give an insight into when these finned unreinforced covers were used from and to.

Keith has also stated assembling early K0s in dealerships and noting the round cover, confirming the SB range to 9000 numbered K0s.

This then means a conflict- if the first 9000 bikes came with a round OF cover, 14mm bolt, then were some dealers replacing the cover without changing out the 14mm bolt? Or were they being fitted from factory, some with the finned unreinforced cover, some with round OF covers, using 14mm bolts? Or were dealers already changing the oil filter covers pre-SB, prior to 12mm bolts being circulated?

Confused as ever...  ;)
Steven




kmb69

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Back in the day, all listed parts were not always available. We frequently got backorder notices and had to wait for certain parts. Honda probably had the first batches of everything manufactured per their bill of materials quantities until they had historical sales data available to order otherwise. The Parts Department Managers did not always order parts on a one for one or whatever the quantity per assembly was basis. For example, when the SB came out with the new part numbers, some shop might order 20 bolts and 10 filter cups. So a 12mm bolt might not have been available at some dealerships for the recall and the old bolt was re-used. You had to get the Customer's bike back on the road and that's the way it was - probably still is.


vnz00

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Hi Keith,
Thanks for the input.
So were all the sandcasts/early k0s you were preparing for sale - they were coming from factory with round oil filter cases? Then if sold post Jan 1970 SB, these were swapped out prior to sale?

This would mean that anyone with a finned unreinforced cover, 14mm bolt, would have Originally had a round oil filter case on their bike, but swapped with replacement cover by the dealership prior to sale.  Same said for any sandcast bike with 12mm bolt, and later finned reinforced cover.

Thanks, Steven.


kmb69

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Steven, I don't really remember when I saw the first finned covers from the factory. I never saw any bikes updated per SB's prior to sale. The bikes were in big demand and selling as fast as we could get them. Parts for the SB's were not always available to all dealers when the SB's were issued. It was sometimes weeks or months before we could actually get the recall parts. It seemed like the bigger, older dealers in California always got them first. They were often allocated based on actual bike orders from the Dealer to Honda. The very first delivery of 750's was based on the Dealer's previous year's sales. The shop where I worked at the time was a new Honda Dealer and got 1 SC 750 where some other shops around Houston got 2-3 in their first shipments. After the first couple of shipments, you could order as many as you could afford to buy within some reason I guess. There were many models available and selling at the time so your ability to bankroll your showroom came into play. Kinda like a lot of businesses, turning your inventory is the goal. It was not until the K1's came out that we had any 750's sit on the showroom floor for more than a day or two. $1500 was serious money back then (still is) and as soon as a Buyer got his bank loan approved, he was riding. Keith
« Last Edit: August 22, 2012, 08:00:59 pm by kmb69 »


mb124

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Hello ,

interesting thread . I have VIN5120/E5306 , a German sandcast . It came with a finned cover with no internal ribs and a 14mm oil bolt .
So this lines up with Steven`s observation on VIN5528 .
Maybe the 14mm bolt was not superseeded with the finless cover ?
A curiosity : E5306 was supposed to be the last engine without a set ring for the main bearing on transmission input shaft . I checked this when rebuilding the engine , it for sure had the set ring . So Honda literature is not 100% accurate and it`s probably difficult to get a 100% accurate conclusion .A lot have happened in 43 years....

Greetings from Norway

Geir

 


vnz00

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Thanks for the input Keith and Geir.
The sandcast engine on ebay at the moment #4252 looks to have a 14mm bolt (pictured), with a finned cover.  I noted this also on another very original bike no. 5548.
Maybe Keith is right.  The SB was issued, without enough supply of the 12mm bolts.  Unfinned Oil filter covers were replaced but the 14mm bolts were not.  Or the techs got lazy ;) But it seems like it happened a fair bit to be a few random one-offs.

The recent seller of the oil filter covers has a K0 up for sale in the 12000 range which he claims is original.  It has a round oil filter cover, however #28 carb caps are not on there (factory recalled as the bike is pre-17000).  The rest of the bike looks original:
http://cgi.ebay.com/ebaymotors/?cmd=ViewItem&_trksid=p3984.m1423.l2649&item=251137545832&sspagename=STRK%3AMEWAX%3AIT

Would love to hear more from owners who bought the bikes new and which month as to which oil filter cover it came with.





Erling

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Wednesday August 20 1969. Got a Honda CB 750 1001676 5/19 E1638. Round oilfilter house 14m bolt. Sunday after in Sweden met 2 other Hondas. They had finned filtre houses! Engine 23xx. Do not remember when I got finned one, and it is black, have just looked to check for the 14mm bolt. But the round one reached an age, where it had at least 3 cracks from the center hole. Don't know where it has gone. Normally I have kept things. Even the massive rubber cusions from inside the rearwheel, and 28 . carbtops. Original engine has not been in use for the past 35 years eather' as a diecast second hand one was acquired for 8xx cc enlargment. And the original should be as was for my old age run about on the first CB 750 to be licensed in Denmark. Wife denies i'm so far jet. And like someone else in this forum says: I'm not qualifyed to do restauration work like described here in the forum. I'm the owner and was the user untill years ago, but it is more fun to ride the fireblade.  Diecast Engine 19216 has 12mm bolthead and grey finned house. If they are reinforced or not I've no idea.
Youers Erling.


vnz00

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Hi Erling, thanks for your comments.  Very interesting observation.  I emailed Vic World for his comments, and they are as follows.  Vics experience supports Erling's report and provides support to the finned unreinforced filter observations a few members have had where using a 14mm bolt, could have come that way from factory.  There are also three reported finishes on the exterior which I have seen in various photos, and Vic has confirmed.  So I hope this sheds light on this elusive part ;)

Hi Steve,
 
Yes, well first, and most importantly, it is a misnomer to think that all sandcast bikes had them.
In fact, they only came from the factory on bikes up to about #1860 and change (yes, I am sure that someone had frame # 3900 "from the start" for example, and he swears that it came on his bike from new!)...but that was simply an instance where a round cover fell onto his bike some 40 years ago somehow.
(Do you remember everything you did day to day 40 years ago?!...I sure don't)
 
But..still they argue it. Those are the number of bikes (from the Factory).
 
So, that said, yes, Chris's finish sounds accurate compared to most that I have seen.
I also have one or two that are painted (engine case grey paint) from the Factory..
Have also seen rough cast finishes on the outside as well, with no paint (don't know if those were cleared or not)
So there obviously were all 3.
 
Hope this helps, and nice to hear from you!
 
Thanks,
 
Vic


vnz00

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Here are some pics I have collected of the Round Oil Filter Covers showing their finishes, just to put them all in the one spot.  To give credit and thanks to their respective owners for the information and photos:

Vic World (Satin Polished fitted to engine)
Mark B (Satin Polished with porosity)
John (sandydogg) (Painted, not Satin polished Finish)
Chris R (Satin Polished, original condition, on bike)

The final one I dont know where I got but I believe it to be original.  It has the as cast appearance on the outside, with no polishing.

It should be noted that to the best of my knowledge, all filters have the same internal 'as cast' appearance.

Regards,
Steven.


kp

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Well Steven, I am compelled to respond. Firstly I agree that the claim that all round oil filter housings are as smooth as a baby's bum is questionable at best and  think the photographic evidence clearly shows that there are variants. I have a cast filter housing that is NOT smooth and shiny on the external surface and was claimed by the owner to be original. I have kept it all these years believing I was scammed but have convinced myself that it could be a genuine item.
However, and I am sorry to to say this, I totally disagree with Vic on this subjet. I have too many photos of later sandcast bikes and owners comments to accept that the smooth oil filter housing was discontinued at VIN under 2000. Let  me tell you that the smooth oil filter housing was still being fitted to sandcast bikes up to VIN 4500 and beyond. Fact and no if's or but's on this subject as far as I'm concerned. Further, all sandcasts fitted with finned covers were fitted with no rib oil filter housings and this ribless  cover was carried on into the dicast production but I cannot attest to this. Whilst I didn't buy a new sandcast to confirm my comments, there are several on here that had bikes from new so I welcome their comment or contribution on this debate.
Never say anything with a sandcast is absolute, just look at the things found on Marks bike. No hole rear hubs is a good example as is the inner casting of the cam cover.
Yabba Dabba KP


vnz00

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KP, you're entitled to disagree- my email wasn't stating anyone was correct or not.  We are all trying to add more info in to knuckle down a range.

I re-read Steve Swans comments on the service bulletin which our mutual friend Bob has.  The frame range given seems incorrect doesn't it? 1783-9954.  The later parts bulletin then refers to the VIN range starting from #1.

I'm not saying Honda documentation got it right, but let's look at it this way - Honda were referring to an oil filter 000 part number to be replaced with 010. This is the finned, ribbed cover.  

There is nothing in that service bulletin, I believe, referring to a round oil filter cover. It could be interpreted that their manufacture records show 000, the finned unribbed version, was in use from 1783, used to 9954.  This would coincide with the observation you have made regarding finned unreinforced covers used until K0s.  Then Honda might have corrected this realising their error, with the parts bulletin starting at #1.

As original as it is, 1853 could very well have come with a finned unreinforced oil filter cover for all I know.  It has wear on it from road blast suggesting it was there from the start.  I can't date a part purely by road blast wear though which is why I'm pushing this thread.

Steve S also confirmed his bike came with one from new, and I don't doubt that.  Nothing to say that the service bulletin VIN range isnt correct but they ran out of the finned versions in the production line and used some stock of unfinned covers to get them out.  Or workshops replaced them during servicing, or an owner replaced his cracked finned cover with a round one because that's what his wrecker had.

The best we can do is listen to first hand accounts and whittle it down from there.  I also seem to remember you swearing that engine cases were never painted at one point but the more input we got by raising the subject, we realized that they were.

Honda also doesn't help with the variances in production changes, with no change in part no's either.  I have a NOS early diecast chain sprocket cover with the same part no as Bobs NOS sandcast finish chain sprocket cover. Mark has a million more such instances documented too so we are aware there is nothing 'concrete' here.

Cheers,
Steven
« Last Edit: September 06, 2012, 08:58:55 am by vnz00 »


vnz00

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Steve Swans post on the Sevice Bulletin FYI:

Honda Service Bulletin CB750 #13, dated 1/26/70 discusses "a modified oil fliter case and center bolt have been developed to prevent oil filter case damage." The S.B. goes on to say, "the modified case has 8 ribs radiating from the center of the bolt boss inside the case......, being fixed with a 12mm width bolt instead of a 14mm bolt, to prevent over tightening." This 1/26/70 S.B. goes on to say the application is "for all CB750 units within the range Frame # 1783-9554." The case pn is 15411-300-010. The S.B. also notes this cover can be identified with the numeral "2" stamped on top portion between center.

Parts Bulletin:
The Honda Parts Bulletin, #CB750-13, dated April 24, 1970, notes this finned cover WITH reinforcement ribbing to fit all engine vins beginning at #1, pn 15411-300-010 -and- to replace pn 15411-300-000.
« Last Edit: September 06, 2012, 08:00:27 am by vnz00 »


vnz00

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We can at least assume that the finned ribbed version was being used by factory from 9954.  Anything prior was round, or finned, unreinforced ;)