Honda CB750 Sandcast
The Restoration Shop => Fenders (mudguards) and Seats => Topic started by: brianhoover on February 22, 2010, 11:30:32 pm
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I’m a newbie here but hope some of you might take the time to help.
It’s taken almost 10 years but I am almost done with my restoration of my non-sandcast KO. It was manufactured 12/69. Frame # 1015507
During a decade of securing rare parts (including brand new NOS Tach and Speedo!) I bought a used OEM non-duckbill KO seat and a nice duckbill seat cover thinking I would have the two mated when I was ready. Sent the both off to Sargent Cycle in FL to have it done only to find out that the older style seat cover did not fit the newer KO pan. They said the earlier pan was smaller and narrower and the older pan would not fit my bike.
If anybody is in the know I would love to have the answers and would be grateful:
1) Did my KO originally have the duckbill style seat?
2) Are the pans different?
3) If the earlier pan will fit my KO, are there any companies selling restored or remanufactured versions? Are any of them affordable to mere mortals?
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Brian try these people. In my opinion it is the best option ,not cheap but what is
"DUCKTAIL SEAL"
http://www.yamiya750e.com/index.php?main....products_id=291
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I just bought a seat foam from this company in the U.K. I'll give a review asap. I'm working with this vendor to buy 10 to 20 at a time. I will be selling these for cost (including shipping for the members. Spread the sandcast/K0 love. Let me know if you need one, I'll put you on the list or you can buy direct at a higher price.
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Thanks for the comments and info...I might be interested in buying some foam, but I'm still not sure If I have the right pan to put it on.
Can anyone answer the three questions that I asked earlier?
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I'll give it a shot................
1) Did my KO originally have the duckbill style seat? Yes
2) Are the pans different? I believe that the 69-71 should do for you....after that it has a plastic document holder, other than the differences in the early sandcast version(fewer holes)
3) If the earlier pan will fit my KO, are there any companies selling restored or remanufactured versions? Are any of them affordable to mere mortals? Never seen a new after maket pan offered without a seat....even Honda NOS of today have few holes but will fit dimensionally...I believe...$250 or more...even the Yamiya seat offered is not correct as it has fewer holes. It all depends on how "right" you want it.
Hope this helps.
The bottom line is to find a trashed seat on ebay if you want correct...methinks
Steve F
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Welcome to the world of restoration. Yamiya makes a great pan ducktail. I measured tonight same dimensions but fewer holes as early originals. I'm using their repo seat in a resto. project. Wouldn't if original. IMHO if u are restoring a bike it's the best you will find. Only flaw I saw was buckles for seat strap. Non sandcast pan should be easy to find. buy yamiyas foam and cover if you are looking to do a "correct" restoration.
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The '71s and up had a spring and associated hole for same next to the latch.
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From my understanding of the ducktail seat there is a few different versions of seat used on the production bikes that i have seen used on sandcast and diecast engine CB750's, there is the real early version where the pan is different and then there were two later 69-70 seats maybe from different suppliers one a puffey vynal top cover and the other a more smooth flat top, and then the K1 seat without ducktail which as mentioned earlier the pan has the extra threaded hole for the seat latch catch spring, otherwise the pan is the same as the two 69-70 ducktail seat bases. TC
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Regarding differences in the SEAT PANS, to my knowledge there are a minimum of three types which will fit the sandcast/K0's..
Early sandcast types (possibly only a few hundred bikes - my#302 has one of them) which have fewer holes through which the foam can be seen, and also a single M6 threaded hole which serves NO PURPOSE whatsoever (and is in a different position to the K1's M6 tapped hole).
Second sandcast (and K0) type which has more holes and now does not have the "redundant" M6 hole.
Then of course the K1 seat pan which can be used directly on the sandcast/K0, but does have the extra M6 hole for the release spring. The fact that the seat trim and strap / buckles on a K1 is the same as sandcast /K0 means that a used K1 seat is ideal to re-foam and re-cover to "create" a sandcast / K0 seat. The M6 hole for the release spring can be welded up, and most people will never know!
With Honda, there is always a "but", if you look closely enough at the detail. On my earliest seat pan (#302), a number of the metal tangs which hold the cover on at the rear edge are actually on seperate metal pieces which Honda then spot welded onto the pan. On the K1 seats that I have, these tangs are pressed direct into the pan. I BELIEVE that on the K1's, that Honda may of increased the number of aluminium fixings which hold the rear stainless trim on from four to six. Oh, and if you decide to buy a NOS K1 seat to covert to sandcast/ K0 type, you will find that the chrome buckles have now been changed to some kind of double arrangement which looks different. You could buy the buckles and seat screws from Yamiya, but whilst the screws are slightly different, the buckles that I got were simply WRONG - too narrow.
Does any of the above matter - that's for you to decide.
Later K2 to K6 seats of course fit, but only if you also using the lock assembly, and in detail the pan is completely different and not suited to conversion to early type.
For my money, particularly if the cost of a used sandcast/K0 seat is too painful, with a little effort a solid K1 seat makes a sound basis for creating that correct looking early seat.
If any one can add to the above, I'm always interested to learn more.
Cheers guys - Chris R.
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What I think I've discovered in the last couple weeks is that the ducktail pan is smaller and norrower than a later KO pan. My assumption that I could use a ducktail cover and foam on this pan prooved to be wrong.
My pan is from a KO ( I had a 1973 K3 so I know the difference....spring latch and plastic compartment) and the ducktail cover I bought would not fit.
I just ordered a reproduction seat with plastic pan but I will continue looking for and original seat in ANY condition. Any leads would be greatly appreciated.
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Brian,
Please drop me an email so I can reply to perhaps be of help.
Steve
sandcast232@yahoo.com
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Hi here are some pics to clear things up.
On the CB750 sandcast and diecast K0's there were Three different seats used.
The low vin bikes had a seat base like this also a bigger 19 litre fuel tank,
(http://inlinethumb22.webshots.com/32725/2225357980102496428S600x600Q85.jpg)
less vent holes and the threaded hole possably for a seat stop wire but not used..
Then the seats used on later sandcasts and diecast K0's there were two types used that i know of, both had the same base..
which looks like this..
(http://inlinethumb58.webshots.com/44601/2590121690102496428S600x600Q85.jpg)
They had different covers a flat type ducktail and a puffy type ducktail
The flat type...
(http://inlinethumb01.webshots.com/19008/2510780510102496428S600x600Q85.jpg)
and the puffy type...
(http://inlinethumb11.webshots.com/43274/2846322250102496428S600x600Q85.jpg)
seen together they are very different looking the closer is what i call a puffy one..
(http://inlinethumb49.webshots.com/35312/2960373280102496428S600x600Q85.jpg)
(http://inlinethumb55.webshots.com/27958/2848065830102496428S600x600Q85.jpg)
then there is a K1 seat that has the latch catch spring this pan is the same as the later sandcast and diecast K0 with the extra hole for the spring and can be used for a K0 with new foam and cover...
The K1 seat pan;;
(http://inlinethumb02.webshots.com/41793/2448033520102496428S600x600Q85.jpg)
and here is the bases lined up they are all the same width.. rhs early sandy, middle later sandy and diecast K0 with two different covers and left a K1, hope this clears it up a bit
There was mention that the trim has more rivits yes the two short stainless trims at the front of the seat have three rivits each side on the K1 pan the K0 pans have two rivits each side the rear trim has 4 rivits on all pans,
and yes the cover retaining tangs on the K1 seat pan are pressed ..
Another thing to note, the bolts used on the very early and the K0 seats have unmarked heads the K1 seat has small #8 bolts TC
(http://inlinethumb58.webshots.com/42425/2179251650102496428S600x600Q85.jpg)
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What I think I've discovered in the last couple weeks is that the ducktail pan is smaller and norrower than a later KO pan. My assumption that I could use a ducktail cover and foam on this pan prooved to be wrong.
My pan is from a KO ( I had a 1973 K3 so I know the difference....spring latch and plastic compartment) and the ducktail cover I bought would not fit.
I just ordered a reproduction seat with plastic pan but I will continue looking for and original seat in ANY condition. Any leads would be greatly appreciated.
Carefull i think some of the repo covers are too small...
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Tom. That's great info for the members and I for one appreciate the fact you posted actual pictures of the various seat types. I tend to believe this and what you have pictured because we do see on ebay some seats are more puffy than others. Could be the material used in the lining and could even be the upholsterer doing the seat, but it is very clear there are differences.
Brian, there is no smaller seat base from an early K0 to a later K0, The dimensions are all the same. Maybe you could post a picture of your pan as it may not even be a CB750 pan. if you have trouble please send me the pictures and I'll post them for you
KP
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Tom, I 2nd what KP wrote !
THAT'S REALLY GREAT INFO !
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Yeah, great info! I think all of my problems are now due to a cover that is too small! Bought it years ago on Ebay...don't remember who I bought it from.
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Hi New here from UK with K0 VIN 1010382.
I bought a brand new Honda K1 seat from David Silver to get a new steel pan, trim and strap/screws. I sold the K1 cover on Ebay and the foam is on Ebay now (bargain if you have a K1). I then got a 'Ducktail' foam from 'Discovers' and told them I thought that the aftermarket cover they sell does not look right and asked if there was anyway they could make me a cover with deeper padding in the 'quilting'. For about 15GBP more their 'supplier' told me he does in fact make a cover with 'extra padding'. I shipped all of my parts off to them and very pleased with the results. OK it's not up to Yamiya standard but much better than the Dave Silver/ CMS ones or any other I have seen.
BTW the repro D. Silver one is made by the UK 'Supplier' but they are hammered down on price so don't fit the superior quality cover and have the time to - as he puts it - 'Give it that extra special care'.
http://i697.photobucket.com/albums/vv340/AshimotoK0/K0seatash1.jpg
http://i697.photobucket.com/albums/vv340/AshimotoK0/K0seatash2.jpg
http://i697.photobucket.com/albums/vv340/AshimotoK0/K0seatAsh3.jpg
Pity we can't get together with the UK people and get him to reproduce a Yamiya type
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Hey all, can someone lead me to where I can get a ducktail foam for my K0 please?
Al
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Yamiya has the best if you are looking for red sponge or complete seats if you want a white sponge type. They also do the best covers with better prices than most
There are other sellers so you ay wish to do some research.
A complete white sponge seat can be had from MRS in Japan for around US$350 which is the equal of the Yamiya white sponge at a US$200 lesser price
The only issue with all these seats is they use the early sandcast base. If that's important then get you own base painted and swap bases
KP
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Im in need of new foam for my K0 [VIN 16,XXX]....anyone have any to spare please or tell me where to buy other than Yamiya which at the moment against the USD then conversion to CAD with duty and taxes at the border is almost $400 by the time I have it in my hot little hands.....
Thanks
Al
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I can understand Yamiya had sold used K0 seat for 952 USD. But is also offering nice used one for 1900 USD ???
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Hello everyone ;)
In my opinion, this 17 hole Ducktail seat Yamiya is way too expensive for its condition,
because in addition the red foam must be completely dry and disintegrate like all seats
in their 70's juice and given the condition of the rusty support...
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Bonjour, mon ami. Nous n'avons pas entendu parler de vous depuis longtemps. Votre œil critique et votre bonne humeur ont en effet été manqués. Vous devez nous dire ce que vous avez fait
Quant au siège Yamiya, vous avez raison. Ils sont chers et un seul type de plateau de siège. On peut avoir un siège MRS avec de la mousse jaune / blanche pour la moitié du prix.
Hélas, le siège Yamiya est le seul disponible et a sauvé la journée pour beaucoup. Une chose est qu'ils sont d'excellente qualité donc pour cela il faut payer
KP
Hello my friend. We haven't heard from you for a long time. Your critical eye and good humor have indeed been missed. You must tell us what you have been doing
As for the Yamiya seat you are correct. They are expensive and only one type of seat pan. One can have a MRS seat with yellow/white foam for 1/2 the price.
Alas, the Yamiya seat is the only one available and has saved the day for many. One thing is they are excellent quality so for that one has to pay
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Hello My friend Kp,
Thank you very much for your sympathetic response :D
I too am very happy to be here a and to be able to share and discuss again with all of you ...
I will explain my long silence to you in PM.
For the Yamiya Ducktail, I was talking about the used one in bad condition with an exorbitant
price of USD 1,900.00 Oups !! ...
And on the other hand for the reproduction they made, this beautiful reproduction made it possible
to save a lot of Owners who no longer had the original Ducktail seat ...
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Ah Yes, my bad I now see what you are saying my friend
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Hi
my sandcast has the VIN 631.
Can someone tell me how many holes my seat pan should have originally?
Best Regards
Johann
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This is a Yamiya reproduction seat, however your base should look exactly the same as this. I often call them a 3 hole, many call them the 10 hole base
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One thing that I have noted with the seats, the seats sold by Yamiya come with 10mm fixing bolts all with 8 on the head , the seat bolts are plain with no markings i do believe
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Vielen Dank Euch Beiden.
Gruß Johann