[Zeta7]

Is there any way to tell if my 883 sportster has been converted to a 1200. Also how much does this conversion cost?

 

[Kainam]

Only way to be able to tell would be to check the bore dimensions.

Nallin racing is having a special on their 1250cc kits, $700.
http://www.nrhsperformance.com/

It would also be worthwhile to get a pair of ported XB (04+ 1200) heads and a nice cam from them at the same time.

 

[Kainam]

883 - 1200 head differences for 04+

883:
1.585" intake
1.350" exhaust
49.5cc chamber (they vary wildly though).
7mm valve stems (vs. 5/16 for 03 & older)


1200:
1.810" intake
1.575" exhaust
62cc combustion chamber
7mm valve stems

They can easily support .550 of lift right out of the box, where all the older heads were only safe to about .500.

 

[Kainam]

I was just looking at the pics of your bike. Did you put that Mikuni on there (HSR42?), or was it already that way when you bought it?

 

[Nathang]

Very good lookin' bike. Even the pix hurt my ears tho'.

 

[Nathang]

You could probably get a pretty good idea if you took out a spark plug and carefully used a pencil or a chopstick as a probe to be exactly sure when the piston is at top dead center, then fill the cylinder to overflowing with oil, then lower the piston to bottom dead center, and used a big syringe, like a kitchen turkey injector, something to measure CC and fill to overflowing with oil again. It wouldn't need to be very precise, there ought to be a pretty notable difference between a swept cylinder volume of 27 cubic inches on the 883 and 36+ cubic inches on the 1200.

Carefully suck the oil back out with a mityvac or something. Wash the cylinder lightly with a squirt of gasoline, suck out again. Hitting the starter while there was a quantity of oil was in the cylinder would be a disaster, it might squirt out of the spark plug hole fast enough not to break something, but I wouldn't bet on it.

 

[Zeta7]

Thanks guys

I took the bike to the shop today and they told me the carb was 3 sizes to big. They said it should have a 38 mm and it has a 40. So i had 2 choices buy a carb or do a conversion. So i dropped a grand on them and they said i would have my bike in about 10 days.Thanks for all the help , ya,ll are great. I,ll let you know how she feels when i get er back.

 

[Zeta7]

Kainam, the carb was on the bike when i bought it, i'm the third owner. The guy i bought it from bought it for his wife but she did,nt like it said it was to big for her. when i bought it he said he thought it was converted to 1200 but was,nt sure. Nathang, thanks for the flowers, yes it is loud. I took the baffles out to see if that would lean it out any, it did,nt the baffles are going back in.