The Harley-Davidson XL1200S performance

whitewheels

Some question here,I hope have a little information.

Heads: What's a good upgrade that still retains the dual plugs?

Intake: I'd like to run an Edelbrock intake and carb but will it fit
the stock heads or do they have to be edelbrock heads? Also will a SE
air cleaner assem. fit an Edelbrock carb?

Exhaust: 2-1 - which has better performance, Thunderheader or SE?

Hamsley

A set of post '04 1200 heads either drilled and tapped to suit for the
extra plug or just use single plugs with a twin cam coil...

Steer clear of Edelbrock heads... they're not worth half the money..

There's also a number of things you can do BEFORE the heads become the
restriction to the power output..

Why an Edelbrock carb ..???? I don't know anyone who has been happy
with one.. I had one and sold it before I even bothered installing it
as the slide would bind...
You will also have to use an Edelbrock air cleaner because I don't
think anything else will fit... they have a different mounting.. be
carefull fitting another aircleaner to an Edelbrock carb 'cos if you
block or restrict the air bleed holes it wont work properly.

Thunderheader probably performs better but it costs ground clearance..

Supertrap allows you to fine tune with the

GreenBike

Thunderheader has a whopper of a torque drop from 2500 almost to 3000 rpm.

I've scrapped the pipes at the collector weld enough times that's going to have a hole sooner rather than later.

If you like the 2into1, go with SuperTrapp pipes, they can be tuned to get a good portion of the torque drop out and they have clearance.

In my next incarantion, I'm staying with 2into2 pipes.

Want more power? Go with a complete system and have them drill the heads for a second plug. NRHS will do it. That way, you aren't having to replace the ignition system also.

From "the Guys who make Land Speed Records" the stock CV carb will do very well up to 100ftlbs torque & 100hp.

Just make the parts you have work better. Don't spend $$$ on a set of heads (for motorcycles) that are made from a company that specializes in cages. It's not worth it. Go with Zippers, Headquarters, NRHS, especially if you talk with them, they'll ask the correct questions to get you the right setup. Be sure you know what you're after specifically.

I had Art N. tell me to fix the mating surface between the heads & exhaust. They don't match very well & the flow is disturbed. He also said that a smaller port (D shaped) is better than bigger. Speed of the fuel/air mix is important. It has momentum and helps to fill the chamber better than a bigger carb.

I pulled the last paragraph from memory so YMMV and memory is full of holes.

highway

I've searched and searched and have found a 180, 200, and 240 rear
tire conversion kit but all I want is a 150. The '04/up Sportsters run
a 150 instead of the 130. Is there a kit out there that will do it? or
is there a simple way to use the later model parts to do it?

Also can I run the Baker six speed with it? I'm planning on getting
either the tire kit of the six speed with my Tax return, and the other
later. But if they're not compatible, then just the Six speed. It's
all about the 'fluff' factor. It may not be necessary or practical,
but hey. It's in there.

GreenBike

Thunderstorm heads or the newer X heads drilled for an extra plug. The stock heads on a Sport are mediocre at best. But having them ported is still a decent option as far as cash outlay goes. The biggest drawback of the stock heads is a bad combustion chamber. It's not compatible with aftermarket pistons for creating a tight squish band.

As has been said, Edelbrock parts are not the best. Stick with the CV carb unless you like wasting cash.

Between those two, probably the Thunderheader. I'd choose a SuperTrapp if I was looking for maximum performance.