doing a 883/1200 conversion on 2003 sportster

[BUBBIE]

ok guys..I did the upgrade and it runs great,,very strong bike now,,I did have to rejet the carb. but the timing was left alone..no spark knock,,,, now the front wheel takes a ride in the air from 1st to 2nd and again from 2nd to 3rd,,,or it spins the back wheel,,,,great mid range power but upper end I can tell that I wish I had put the bigger valves in the 883 heads,,,thats what I will do now that I will have a little down time on my hands,,I have but 1185 miles on the upgrade so far,,,but I go back in the hosptal tuesday morrining for knee surgrey again,,,so I will be off my legs for awhile,,(not too long I hope),,so while I'm down,,I plan to pull the heads an do the valve upgrade now,,and see what that will do her,,,,will let yall know as comes together....

The only thing you are missing without the larger valves is the Top end.. I would not monkey with the valves and enjoy the TREMENDOUS low end you have.. Sporty bikes to 80 mph is about all you can expect THEN the SE HEADS and Cams are needed... Lot more $$..


Any one here have an Idea to get more top end with out of this bike loosing the low end.. Chopper and or R.Bingham come into mind here.. Let's See if they chime in? I just wanted to know.

Sounds like a real MONSTER.. Should Beat the Pants off any 1200 even the R's.

signed....BUBBIE

 

[JIMJAM]

ok, thanks for the info. there BUBBIE,,,I have heard that bigger valve and doing a little porting (no polishing) would really help her out,,,but lets see if anyone else will jump in here an help me out with some comments on this,,,,ANY AND ALL COMMENTS WILL BE GLADLY APP. ,,THANKS FOR ALL THE HELP

 

[Jack Klarich]

883 valves do out perform 1200 valves, with a fresh valve job and radius the seats and trim the guides and you will be good to go, We have done this on 883 models and they FLY

 

[BUBBIE]

Terry Jackson
Start The Engine
Ride: 2002 Sportster XL 883

Join Date: Dec 26th, 2008
Location: Flowery Branch, Ga.
Posts: 40
My Mood:

Re: what is the best 883 to 1200 conversion without spending too much $
Good info Bubbie. That is exactly what I am considering. I want the torque, but at my age, don't need a lot of HP. And I figured the 883 heads would make more torque.

Quote:
Originally Posted by BUBBIE
ONE LATE NIGHT TALK WITH JERRY BRANCH OF BRANCH HEADS....

one late evening i made a phone call to a calif. shop...

THINKING to leave MY return number ,,, was quite surprised that someone answered the phone..

JERRY BRANCH was the answer..

I told him what I had started to do with my 1995 883..wanting LOW end power and the best way to get it...

I had already BOT wiseco 1200 cc pistons at 10.5/1 ratio

HE SAID I couldn't use HIS heads with those pistons
but since I was on a LOW budget and doing MY own work:::::

HE suggested
" " " " " " " "
BUY new HD 1200 barrels using the wiseco pistons at 10.5/1

use the stock 883 heads (give them a lap job)

modify the carb with proper jets (.180 )??? and use a older model ?1200 sport needle..

Use a good pair of slip-ons (scrm'n eagle)
slap it together..... break it in @ 500 miles

"THEN go find a POLE and climb it"--- call me back tell me what you think

I then asked HIM what cams to use??

HE SHOUTED his reply "there you guys go again ,,, wanting LOW-END power and torque ,,, then caming it all away...

I followed his advice (other than the pole)

REALLY HAD A HOT 1200 CC BIKE...

BOY DID I surprise(my self included) a few of the guys I rode with...
(in front of)

THANKS to JERRY BRANCH for answering his phone one late night YEARS AGO.

signed....BUBBIE

The above copy OLD post is for information ONLY.... signed....BUBBIE

 

[BUBBIE]

Excuse me for misinterpreting your comment. My bad.

As for your question to a question, re-read my post.

**********************************************
Yes,, I See your post saying Your bike and Speed.....Sportsters DON'T usually have a lot of umph after 80mph and there I draw a line for comparison.(legal speed limit in Texas freeway) that is MOST sportsters,,,

I'm Sure Your bike didn't break Any "Time Records" getting to the top speed you talk about.. Fast was my intent not Top Speed....

signed....BUBBIE