Topic: making custom oil lines for honda cb750?

[motorlou]

hey guys, i am getting ready to start another honda project (1975 cb750) and had a question about the oil lines on that. i would like to make an oil bag for it but i was wondering if anyone could point me on how to go about changing the oil lines. i haven't actually sat down to look at how they go into the engine but the other end that screw into the stock oil bag will definately not work for what i have in mind. are there any topics on this, looked around a bit but nothing readily came up. thank you in advance, Lou

[danfr]

Hey Lou,

Keep digging around on the forum, I had the same questions as you and found them here. I believe a common fitting for custom oil tanks is AN-10. I believe the hose size required is close enough to work with the stock fittings that go into the engine.

Alternatively, Cycle Exchange does offer oil line adapters to help with the conversion, but with the Cyclex ones you will be reducing the i.d. of the hose which (once again) you will want to do some research to decide if you want to reduce the cross-sectional area of the hose.

Personally, I'm going with the AN-10 fittings.

Cheers
Dan

[gsb]

Hi !
I make mine by lokal Hydraulic -shop for 15 euros ! I buy also 2 Viton seals ,and polish conectors myself . For me max 20 bucks .
 gsb

[70CB750]

Easy enough to do, if you reuse original fitings. There is not much pressure in those lines, even clamp will hold. I made mine crimping SS ferules.

Now if you want to replace the tank fiting with original tank , thats a different story  threads are M22and M26 japanese paralel or something like that.

[Geeto67]

First off - its a Tank not a bag. Tanks have a rigid structure, bags are soft and floppy. Every time I hear someone say oil bag I just think he's read too many issues of "the Horse"

Here is the only advice I can give you: make sure you keep the lines the same internal diameter as stock. I've seen too many guys neck their oils system down to 3/8th to fit an HD or triumph tank and then wonder why their cam bearings seized and their cam cracked in half (by the way, a cb 750 can run with a broken cam on two cylinders depending on where the cam broke).

These engines make oil pressure like a car (40-60psi vs 15psi max for same year Suzuki Gs750) but they also need the volume.

[motorlou]

First off - its a Tank not a bag. Tanks have a rigid structure, bags are soft and floppy. Every time I hear someone say oil bag I just think he's read too many issues of "the Horse"

Here is the only advice I can give you: make sure you keep the lines the same internal diameter as stock. I've seen too many guys neck their oils system down to 3/8th to fit an HD or triumph tank and then wonder why their cam bearings seized and their cam cracked in half (by the way, a cb 750 can run with a broken cam on two cylinders depending on where the cam broke).

These engines make oil pressure like a car (40-60psi vs 15psi max for same year Suzuki Gs750) but they also need the volume.

i been in a few issues of the horse before brother, see pic below of this months issue (article written by yours truly).  i really do appreciate the advice though. i have never done this before so i came to get advice from the pro's here on the forum. thanks again, Lou

[Elan]

cool bike

[motorlou]

thanks elan, i make them to sell (what i do for a living). this one is currently up in the bay area with it's new owner. i have a build thread of this project in the "project" section call "cb550 veloce racer".

[danfr]

Very nice! Love the pipes and rear fender!

[Geeto67]

The oil "bag" thing is just a pet peeve. Like when people call an engine a motor (motors are electric, and I am guilty of this one sometimes only to be corrected by my engineering friends).

You do very good work. Too good for the horse in my opinion but try to get one of the other custom bike magazines to look at a non HD custom, its hard.

Most people forget the lengths Honda engineers went to to design the cb750 engine. Plexi windows in the cylinder to view combustion, flow benches to tune the intake tract from airbox to combustion chamber, really advanced stuff for the day that is common place now.

The secret to the cb750s longevity is the oil system. The only bikes I have ever seen with bad engines were bikes that were abused/crashed, neglected, or someone changed the oiling system for the sake of style.

[70CB750]

Correction, threads on the oil tank are M22x1.5 and M24x1.5.

I don't think there is a standard fitting sold in US to fit these.

[Geeto67]

Actually granger stocks that fitting size and it isn't hard to come by at all. Ironically m22x1.5 is the same size as the fittings on an bmw e34 m5 oil cooler (but it has been years since I owned one). You can get nice aeroquip fittings in both those sizes. The bungs on the other hand are harder to come by but something tells me if you needed to you could buy the die and thread a piece of pipe if you needed to.

[70CB750]

Hmm, you don't say:)

Thank you, I will check them out.

[lucky]

hey guys, i am getting ready to start another honda project (1975 cb750) and had a question about the oil lines on that. i would like to make an oil bag for it but i was wondering if anyone could point me on how to go about changing the oil lines. i haven't actually sat down to look at how they go into the engine but the other end that screw into the stock oil bag will definately not work for what i have in mind. are there any topics on this, looked around a bit but nothing readily came up. thank you in advance, Lou

There is something you need to know.
The stock Honda fittings on the engine side are very trick.
Keep those.
One of the fittings is cast and is less than 90º (unusual), so that both hoses
will fit between the frame and foot peg without being squashed or bent.. Very
important.

[754]

They were oil bags...long before the Whorse...
 I believe it came from chopped Sportsters in Cali

 Look at the 60,s XLCH.. It looks like a bag..
 It doesnt bother me at all ...springer seat pisses me off though.
 There are lots of slang terms for bike parts, some stray from the regional area they started from..
. One we had here.. Catsquasher........used mostly around here.

[PeWe]

...or just order a pair replacing the old ones. Not the cheapiest solution but will work without any struggle. I trust the seller :-)

Honda CB 750 Four K0 K1 K2-K6 Stahlflex Ölleitungen Stainless Steel Oil Hoses

http://www.ebay.co.uk/itm/400549916151?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649

[70CB750]

I did that for $40 or so with local shop supplying the hose,McMasterCarr ferrules and crimping it myself.

[lucky]

They were oil bags...long before the Whorse...
 I believe it came from chopped Sportsters in Cali

 Look at the 60,s XLCH.. It looks like a bag..
 It doesnt bother me at all ...springer seat pisses me off though.
 There are lots of slang terms for bike parts, some stray from the regional area they started from..
. One we had here.. Catsquasher........used mostly around here.

"springer seat pisses me off though." Why ? Because it has no springs?

[754]

No because,
 They were called sprung seats forever.. Or spring seats..

 And springer was the name of  at least two styles of forks, since the 30,s or earlier, they are still called that. They have been building them over a hundred years.
 Seats that were sprung had a few other names depending on how they were sprung, ie FLOTING sest in thr. Teens or twenties.. Pogostick seat came in at the end of the thirties...
So till10years or so ago. When you said a bike or bicycle had a springer, it meant the frontend..

..asshattery abounds..

[Ricky_Racer]

http://www.ebay.com/itm/151100191396?ssPageName=STRK:MESELX:IT&_trksid=p3984.m1555.l2649     RR

[70CB750]

Holy crap, I should start making those.

[Ricky_Racer]

Yeah, you could... Lessee, based on the description in the eBay listing: time spent chasing used hoses that cost $30-60, PITA removal of the original old hose and ferrules, shipping to Europe for the proper sized hose, cost of the new ferrules, cost of refinishing the hose ends, cost of cutting the hose, cost of installing the hose, cost of crimping the ferrules, cost of shipping the completed assemblies back to the US, Ebay and Paypal fees...

Hmmm... doesn't look like a good way to get rich.    {sigh} Well, you could always make 'em up using the skinny US hose and cheap flat ferrules and save a little bit. But the finished product will look like 

Whattya think? RR

[70CB750]

You gotta wonder why they don't ship the hose to USA to save some time and expense?

The story is a good promo for people who know nothing about engineering and manufacturing.

[Ricky_Racer]

I'm really must limit this discussion, but your suggestion was tried. Have you checked the cost of shipping an oversized roll of braided stainless from Europe? Then the assembly costs are passed to the US. Heck, even finding someone in the US who has the correct jaws for the Honda-style crimping is problematic. Fortunately, we have friends and associates in Europe who can assist us in producing parts that are difficult to make in the US.

Seriously, if you think it's worth it to you, go for it. It's a lot easier to armchair a dream than to make it really happen.

Yeah, we make these and we go through the hoops to bring uncompromised quality parts to the CB750 enthusiast. Sorry that our chat has to be so short, but we're busy designing and manufacturing parts like our reproduction Giuliari seats (US, Europe, UK components), Read-Titan cafe tanks and seats (US), and a range of other CB750-centric products.

By all means, use your considerable expertise to join us in investing the time and financial resources to create new or better products for our fellow SOHC enthusiasts. Most will appreciate and support your efforts. Just don't expect to retire on the proceeds from this niche.    RR

[PeWe]

I have now ordered a complete oil line set together with other CB750 parts, no need to vandalize my old with a result not that good as the CCC ones. If I let a mechanic work with my car or motorcycle for one hour, the labour only exceeds the cost for these oil lines shipped to my door. If you see what you get, it's a very good price when the pair is complete. Other alternatives are usually hoses only.
 
(Earlier this year I found the HD primary chains at CCC too. They have parts not found anywhere else. Like the silly washer locking the ignition switch in place)
When I get them + other parts, oil can be filled and the slooow project can continue.