Originally Posted by biteme

Thanks guys and yes it's SIRR1....

I was lurking in the shadows checking out the responces and I had to join this forum, cool site!

I had no idea this was here, lots of great info, I have been reading all the different forum posts gaining knowledge, thanks for letting me in!

Tigermaster, the bottom end is XR400, here is how it came together.

You take the 400ex crank and counter ballancer and installed them into the XR4 center cases, using the XR4 internals, transmission gears, shifting drum, shifter shaft, center gasket and bolt her up.

The clutch side is all XR4, I did have the option to add reverse from the TRX400ex bottom end but I would have lost the XR4 kick starter, so no reverse.

The left side of the motor or stator side is where the 400ex parts come in to play.

I installed the complete 400ex fly wheel assembly on to the 400ex crank.

I then installed the 400ex stator, starter gears, starter and stator cover.

The only modifications needed to the entire motor build was to drill and tap 2 holes for the starter to mount on the right center case.

Naturally I used all new bearings, seals and gaskets on the build, and I did update the transmission from 1996 to 2001 XR4 gears, shifting drum along with the stronger 2001 kick starter shaft, which fixes all of the internal problems on the older XR4's.

The motor went together really really easy, I had read all of the horror stories on how hard and how expensive the build would be and I totally blew away both fear factors.

What I did was to search ebay for the parts needed to build the e-start motor, I got lucky and picked up a 2005 400ex complete bottom end for $390.00 shipped to my door.

This bottom end had all of the motor parts needed for the build and what parts were left over like the center cases, transmission, clutch, XR transmission and kick starter shaft all were sold on ebay to help recover the cost of the build.

Since I built the motor I have seen on ebay several other bottom ends priced under $500.00, i was in a hurry and wanted the parts now, I could have been patient and saved some cash but spring was here and I wanted to ride the bike.

I did have to purchase on ebay a few 400ex parts to make the electric start work as it did on the 400ex.

400ex wiring harness $20.00, voltage regulator $40.00, High Rev CDI $60.00
after market starter / headlight switch $50.00, Solenoid $50.00, Battery, $50.00, CBR600F1 battery box $10.00

Right now I have the total E-Start build down around $400.00 and I still have a new XR400 Hot Rods Crank to sell yet that I never used on the original XR400 build.

Wow sorry for rambling, I love talking motorcycles!

TJscott2012 you mentioned little mud flap things?

I am sorry I don't get what your talking about....please get back to me so I can figure out what you mean.

Thanks again for all of the kind words on my Sumo and thanks for letting me into your forum.

SIRR1/Biteme