300ex sacrificed to rebuild 350x, interesting info inside

[Louis Mielke]

Ok so I've always seen trikes as higher on the food chain than quads and I'm working on this 350x and I needed a shift shaft.

And eye balling the 300ex you just swear that the lower engine is identical to the 350x, if not darn close. So I thought about it and decided, threw the EX on jack stands and ripped the side cover apart.

Now there's probably someone on this board that already knows this but they didn't reply to my thread so I'll claim it as new info untill informed otherwise.

THe 300ex and 350x shift shafts are INTERCHANGABLE!

Discontinued huh honda? Haha, I think not!

The only difference I can find is that the snap ring is a little farther out on the shaft, big woppdee doo! I have a shift shaft for my 350! and not only that but after more examination, the chain cover, and many other parts are interchangable. I'd even wager that if you swap the ignition systems you could bolt the electric starter cover up to the 350x engine cases. Might need some slight modification but not a whole lot of work. I doubt the EX electrics would be enough power for the 350 though but who knows.

As I said someone may have already known this but I couldn't find it by searching the board and no responce to my previous thread, so now, anyone needing a shift shaft for thier X, order up a plentiful EX one!

[jason85atc250r]

me and my brother just found out that 300ex oil pumps will work on a 350x engine.

so ther is one more part that will work

[hrc200x]

HOw does the price of a discontinued 350x shaft compare to a 300ex shaft thats instock?

You can also see on a 300ex side case places where oil cooler lines and decompression arm next to the kick start should go if it were a 350x, but they never drilled or tapped holes. Pretty sure 250x/300ex motors are base off 350x ones. I've often though of using a 300ex head on a 350x since it has bearings on the cam, but am not sure if it would fit. I think they are still 4 valve, just use a single headpipe right?

[Louis Mielke]

They're about the same price actaully.

The 300ex and 350x heads are not the same, the 300ex is still a 2 valve head.

I would think it would be easy enough to update the 350x head with needle bearings.

[hrc200x]

They are 4 valve, don't know what that large hole is above the right upper valve spring?
http://cgi.ebay.com/ebaymotors/2004-...spagenameZWDVW

[Louis Mielke]

WEll open mouth and insert foot. My mistake. I'm a (whoop didn't relise that was a filtered word) dumby. Sorry.

I dunno though. The 350 topend does seem alot more masive than the 300ex. I would wonder if the head would fit on the studs.