Knucklehead gas tank

[ldfly112]

I have found a 1939 knucklehead gas tank just wondering if it will work on my 1937 UL Thanks if you can help

[Rubone]

Yes, it will work, just won't be correct. Knuckle tanks will work on a UL but not the other way around due to clearance under the tanks. They also hold about 1/2 gallon less fuel. There will be lots of room above the heads.

[Jerry Wieland]

You might be able to trade for a SV tank.

[ldfly112]

sounds like it will be a very noticeable difference. Not sure what i am going to do im not concerned about the bike being totally correct but i want it to look right Thanks for your help

[larry]

The difference is in the part you don't see. I've wondered why the factory made two different styles when the OHV tanks would work on all Big Twins.

[JoJo357]

sounds like it will be a very noticeable difference. Not sure what i am going to do i'm not concerned about the bike being totally correct but i want it to look right Thanks for your help

Here are 2. 1939's, the outward difference is...'Harley' Noticeable 112. You'd only slightly notice them in a crotch position, like these photos~~Where's Waldo?

*M.A.D.*

fullsizeoutput_1941.jpeg



fullsizeoutput_1943.jpeg

[Rubone]

If you run alloy heads it will take up a bit of the space. However Jojo's pics aren't great since one is a Knucklehead. Note the bottom shape of the knuckle tank and how straight it is all the way to the gas crossover line as opposed to the rounded belly of the UL tank. And the left tank has no depression at all, the clearance is for the spark plug on the right tank.

[BNSONS]

Sell the knuckle tanks (they're worth more than the flathead tanks) turn around and buy the correct tanks you need.

[JoJo357]

https://youtu.be/h_SK8hKpWzA

*M.A.D.*

HarleyDavidsonKnuck_1938.jpg
harley-side-1-e1575915673486.jpg

[ldfly112]

thanks for all the pictures and sugestions I am going to install the knucklehead tanks and see what they look like my next meet will be Oley if i need i will try and find a set of ul tanks. I will be holding on to the knuckle head tanks never know what the future can bring

[Rubone]

Here are a couple of actual pictures of Knuckle tanks on a UL with aluminum heads. Red tanks are knuckle, gray are SV. DCP_4771.JPGDCP_4774.JPGDCP_4772.JPGDCP_4773.JPG

[JoJo357]

Yes, it will work, just won't be correct. Knuckle tanks will work on a UL but not the other way around due to clearance under the tanks. They also hold about 1/2 gallon less fuel. There will be lots of room above the heads.

#2 post.

You could have saved everyone valuable time Robbie, if You would have slapped & swapped those tanks after the #2nd post--haha.
Nice job!


*M.A.D.*