Iso intake


Well-Known Member
Unfortunately, the 33669 was the only slanted application intake that was ever made for the HS50 engines. People have used the HS40 slanted intakes (part number 33301) on them but these pictures will show the caveat to doing that

Intake gaskets swapped to show how the ports match up, Left #33669 HS50 intake, right #33301 HS40 intake....

Note the light showing though when an HS40 33301 slanted intake is bolted up to an HS50 block with OEM gaskets.....

Again people have fitted them anyway though, The best ways were to fill in the intake port on the block at the squared off void to get an ever important solid gasket seal as well as being able to match port the flow. I've seen some people twist and tweak till it covers the gaps, tighten it down and call it good though....guess it depends on the builder and how much common sense they have.

Also note that the HS50 intakes (and carburetors) did have a physically larger internal port to go along with the larger port in the block then the HS40 ever did, so you are dropping down a little there as well when doing that.


Active Member
I agree putting the black widow intake manifold on a five horse power HS 50 does not line up perfectly. What I do is take a little JB Weld and put it on the bottom of the intake port to cover up that mismatch. It has worked well for me and does not require any additional parts. And makes something that is readily available more versatile


Active Member
To show a little better using Mark's picture, the red arrow is where i put a dab of JBweld on the intake port. I have used the larger gasket technique too. Either works fine. But as a rule, i put the JBweld dab on all Tecumseh hs50 motors i work on at that red arrow. Because you never know when you need a slant intake. And that version is readily available, and fairly priced (much cheaper than say the ebay versions).

I have also tried cutting a stock hs50 intake manifold, and re-weld it at a slight angle. This of course is even cheaper than the BWms version. And of course lines up perfectly. But i haven't actually tried using one yet, so the jury is still out...