Topic: cb750 oil tank lines question

[avoca]

Hey guys.  First off, this is the oil tank I have.  I don't know what year/model bike it's from since my bike was thrown together from all different years before I bought it.  Anybody have an idea?  Also, it appears that most of the lines from it are disconnected and missing and I don't know which hole/hose goes where.  I'm also having problems finding it in repair manuals and other online sources, and so I thought I'd drop a line here and see if anyone has a schematic or could quickly describe which hole from the oil tank goes to what hose and where that hose goes.  Also, a great place to get new hoses?  Thanks!

Oh one thing, the picture isn't mine however my tnak looks exactly like this.

[Stoli]

On the CB750 SOHC engines, the rear most oil hole is the feed and the foremost is the return. I don't want to give you bad info regarding your tank as I am not familiar with all the different years but I think the threaded fitting just forward of the left thumb in the picture is the feed, making the other fitting the return. To confirm, remove the cap and look in the tank and the one with the tube extending up towards the top of the tank is the return. The non threaded fitting on the tank would be the overflow that goes to the similar fitting on the rear of the crank case.

[avoca]

On the CB750 SOHC engines, the rear most oil hole is the feed and the foremost is the return. I don't want to give you bad info regarding your tank as I am not familiar with all the different years but I think the threaded fitting just forward of the left thumb in the picture is the feed, making the other fitting the return. To confirm, remove the cap and look in the tank and the one with the tube extending up towards the top of the tank is the return. The non threaded fitting on the tank would be the overflow that goes to the similar fitting on the rear of the crank case.

Hey great!  Thanks so much   I seriously couldn't really find anything anywhere explaining this so I highly appreciate it!!!

[Stoli]

Download the CB750 shop manual(s) from this site. There is a really good diagram of the oil flow in section 3. In the '78 manual it is in section 2.

Not sure about a good source for the hoses. I've noticed a lot of guys take the old ones to a hydraulic shop and have them rebuilt. You would need a set of usable end couplers for that so maybe buy some used hoses from ebay and if they leak, have them rebuilt. As far as I know, the location of the engine holes didn't change over the years but the oil tanks did so figure out the year of your tank and try to find some hoses for that.

[avoca]

Download the CB750 shop manual(s) from this site. There is a really good diagram of the oil flow in section 3. In the '78 manual it is in section 2.

Not sure about a good source for the hoses. I've noticed a lot of guys take the old ones to a hydraulic shop and have them rebuilt. You would need a set of usable end couplers for that so maybe buy some used hoses from ebay and if they leak, have them rebuilt. As far as I know, the location of the engine holes didn't change over the years but the oil tanks did so figure out the year of your tank and try to find some hoses for that.

Excellent.  Thanks, and will do!  Some lines I have and could just be rebuild.  I think I'm missing one though;  it's the one on the top and back side of the oil tank. 

[bjbuchanan]

The holes are set up so that you can't mismatch the hoses and drain plug. If you have hoses in hand you know immediately what I mean. That is probably the reason that there is no info on it.

My suggestion is to get some used hoses from a reliable member. They rarely if ever go bad and aftermarket is mostly gimmickly stainless braid hoses with smaller ID hose mounted to stock fittings. I don't think I have a spare set but if you post a WTB in the classifieds you will get a bite.

I'm sure Bill Benton has about 100 of them lol

[seanbarney41]

I have had a couple go bad over the years, but yeah, they can get really crusty looking and still work fine.  There are a couple variations for the vent/over flow over the years and it's hard to find the correct sized rubber hoses.  Wish I had more specific info to post here, but it is posted on the site somewhere.