modding Subaru-Robin engines?

#1
Hey everyone, I am looking for some info, tips, suggestions for modding a Subaru-Robin kart/bike engine.

I have experience modding Honda/clones and Briggs flathead, and want to pick up a subaru robin to mod and put on one of my karts. I have and LOVE a subaru wrx and loove subarus so please to try to talk me out of a Subaru. Plus I have got a few honda clones and briggs to play with too.

Which Subaru Robin engine has the most mod/aftermarket support and mod potential? I'm looking at the ex21 and ex27 ohc engines. I believe I've seen cone airfilters and headers for both and seen an arc billet rod, and I think flywheel for one or the other if not both.

So which Subaru ohc engine should I look for? I really like the idea of the slightly bigger ex27, but if there is more aftermarket stuff the the ex21 I might go with the smaller one.

I KNOW I will at minimum want (need) a K&N/Uni style cone airfilter, header and jets for stock carb. Hopefully billet rod, billet flywheel if possible.

Please help me decide on which Subaru Robin ohc engine to buy and lightly mod.

Also, if any of you know where to get Subaru Robin aftermarket parts, pleeeeaaase let me know!
Thank you!
 
#2
Since they discontinued the small engines, parts chain may be iffy, and there's no real advantage for performance use. I like the OHC idea, but a lot of good pushrod stuff is out there, cheap and plentiful.
 
#3
I have a Wisconsin robin ey27w which is a 8hp engine, I believe, hard to find info on it but I was lucky enough to find a pdf file via google... either way it had a cracked block that I got welded back together and I actually found an airfilter for it on amazon which came from china that was perfect. I about to place it on a mini bike but im going to need to rig a jackshaft bc that block is massive. They are hard engines to find but I did find one for sale in dallas for $300.
 
#4
I picked up an Azusa minibike that came with a brand new ex13 4.5 hp engine. I looked around for parts to do upgrades but didn`t really see anything. It runs incredible stock, so smooth. Made in japan and has a tiny mukuni carb from the factory. Great motor for a run around bike.
 
#5
Look for a KX21, they were sold for karting application and have a few small changes from the ex21. Not a lot of aftermarket stuff available, there is a supplier in australia who sold a mild camshaft and other bits. Very reliable engines.
 

delray

Well-Known Member
#6
Look for a KX21, they were sold for karting application and have a few small changes from the ex21. Not a lot of aftermarket stuff available, there is a supplier in australia who sold a mild camshaft and other bits. Very reliable engines.
I remember seeing them in the past and I believe they are over head valve chain driven cam.
 

Top