Fuel Tank Types

[Hend238]

I'm looking at buying a used replacement fuel tank for my Nighthawk S 750SC. Looking at the part numbers on cmsnl.com I see different part numbers listed for the 700SC and 750SC. Some are cross referenced, others are not. There is reference to Type 1 and Type 2 as well. Can anyone shed light on what possible differences there could be in these tanks?

The tank I'm looking at has a p/n of 175A1MJ1010ZA which is listed in the 700SC parts breakdown but not the 750SC. What is listed is p/n 175A1MJ1000ZA/ZB (Type 1 or 2) which is also referenced in the 700SC breakdown as compatible. I'm at a loss of whether this used tank is compatible with my bike or not.

Clear as mud?

[mollusc]

They're probably the California vs. 49-state tanks.  California tanks don't vent through the cap so they have an additional hose connection on the bottom for a vapour line.  Since the 750S was never released in an emissions-compliant version, the California tank part number won't reference to that bike.
I believe that the Cali tank should work with the 750S.  You probably just need to find a charcoal canister for the vent line.

[Hend238]

Thanks for the reply mollusc. I didn't realize that the California tanks vented that way.

There are actually two more part numbers for the 700S that reference the California version of the tank. 175A1MJ1870ZA and 175A1MJ1870ZB. The part numbers 175A1MJ1010ZA/ZB for the 700S are detailed as "except California" and for the life of me I cannot see why this part number(s) wouldn't be compatible with my 750S and how they could differ from 175A1MJ1000ZA/ZB that are also detailed as "except California". They mystery for me is the Type 1 & 2 designation. The 870ZA/ZB and 1000ZA/ZB tanks have it. ZA being Type 1 and ZB being Type 2. The 1010ZA/ZB tanks do not have this designation.

[mollusc]

I have a very vague memory of someone saying that the rubber mounting pegs were different on one year of the 700S, but I may be mistaken about that.  If it's true though, then that would mean that the tanks would be different to accommodate them.

[Hend238]

Interesting. These part numbers I've been quoting are all from the same year - 1984. Could the 700S have different mounting compared to the 750S? Seems strange that it would but one never knows. Google has turned up nothing unfortunately.

[Hend238]

Well I think I have it figured out. The type 1 and type 2 tanks refer to the colour code. Also, the 1000ZA/ZB p/n look to have been replaced by the 1010ZA/ZB p/n.

[mollusc]

I did wonder if the two different colours were the two different codes.  That would mean 10 different tanks in all (I believe that the California model was not produced in 1986).