883 to 1200

[Tigger883]

Hi, I'm the 'wife of Iain' who's been considering converting 883 - 1200, I just found his note to you!! Yes, I'll be really interested to hear how it goes; I don't understand all the technical details/advantages, but seems to me once you have a bike you love, how much better to adapt than trade in....
Enjoy...!Jane

[Aardvark]

Hi Got the bike back today after the fueling problem turns out the wrong fueler was fitted .Took it for a spin its like riding a different bike worth having the conversion done dispite the out lay knowing things that i know now probably done things different but still glad i did it Regards Bob

[SJC69]

The H-D 1200 EFI conversion kit:- 07 on
Just bolt on out the box but does requires EFI Remap etc.
29784-07
Screamin' Eagle® Sportster® 883cc to 1200cc Stage I Conversion Kit

This complete conversion kit will alter the personality of your 883-equipped Sportster® model. Designed to bring your XL883 model up to XL1200 specifications, this kit includes Sportster® Stage I Air Cleaner Kit, XL1200 Cylinder Heads, XL1200 Cylinders and Pistons. Kit includes black highlighted cylinders and cylinder heads. No case machining is required for installation. Street legal when used with stock mufflers. ECM calibration required.
Link



Pre EFI you can just replace or rebore the cylinders and fit new pistons, then rejet/adjust the carb if required.

Easiest and most popular method is to used dished pistons to lower the compression or otherwise you have to relieve the combustion chambers a lot more and skilled work or replace the cylinder heads for 1200 H-D or Buel ones.

The 883 heads have smaller valves and combustion chambers than the stock 1200

As been mention before it is not just a simple re-bore of the cylinder, you need to remove a lot of metal first, thus a lot of places for speed, convienance & cost use new 1200 cylinders.


Why do it? A lot of performance increase that is just a bolt on in most cases.
Pre EFI it is easily a DIY task

If you don't change the gearing it will pull away like a rocket, the 1200 normally carries more teeth on the front pully &/or in the primary.

To change it you need a new belt , front pully and a method to change the speedo ratio on the electronic speedo's more cost.
Pre 07 1200s also run different cams to 883s.

Used Stock 883 cylinders and pistons are not in great demand thus are not worth much at all, I bet a lot end up as ashtrays and doorstops!