I’ve been wanting to put a 400ex engine in a 350x for a few years now. When I originally starting searching I couldn’t find anyone who had actually completed the project; just speculation or in some cases abandoned projects. Then came along “Top Notch 350x” who was actually successful in the idea. Whilst he didn’t write a long detailed build of it, he did post some really important details and so thus far I believe he’s the only one to actually go through with it.
The bones of the project:
I originally bought this 350x back in 2011. The frame was trashed so I bought a pristine 86 frame from someone here on the boards. I actually ended up selling and rebuying this same 350x twice. It’s not going to be sold again, it’s a solid foundation for what I want to do. Here’s what it looked like the day I brought it home (with the bad frame):
This is what it looked like before I started tearing it apart:
Part of the reason I haven’t started until now was because I was waiting for the right deal to come along for a 400ex. Ebay has engines priced for what I can get a whole quad for which if I bought the quad I would also get the carb, electronics, exhaust, etc. So it didn’t make sense to buy just the engine. I found plenty of good deals on first gen 400ex’s but I wasn’t going to do it unless it had reverse too so I needed a 2005 and up. Finally the right deal came along-I traded another 350x I had for a 2006 400ex with first gen plastics. This thing was hideous and was obviously ridden hard but the engine ran good and that’s all I really cared about.
I had quite the time getting this engine out as the swingarm bolt was seized to the bushings. Had to cut it out.
Got the engine out and traded the roller for a kx80 project which I then sold on craigslist. So overall I did much better than buying just the engine online, plus this way I could hear it run.
And here’s the engine sitting in the X for the first time. Only the bottom bolt is holding it.