I have noticed that whenever the topic of Engine conversion is made that Harley is always showing kits that upgrade a 883 to a 1200, or 96 to a 103 or beyond. I have yet to see it mentioned about upgrading a 1200 to an 88 although there are companies that do accommodate owners of the 1200. My theory on the subject is perhaps it would discourage their marketing strategy to encourage you to buy the larger models. Would I be correct here or can one of those kits be also used to enhance the 1200 model Sportster?

 

The Harley "upgrade" kits, as well as many of the popular aftermarket kits, consist of simply replacing the cylinders and pistons.

You can "upgrade" a 1200 to 88", but it involves a complete motor tear-down (splitting the cases) in order to modify the case internally for extra clearance.

 

Hd only offers 1200. Aftermarket can go 82", 88", 90", 89", 106" and other combos. It's expensive! That's why most port heads with cams. You can make great power with a 1200 or 1250

 

You have to have the spigots bored to fit 88" and above...not a garage project for sure.

 

I have seen 88 Kits for 1200's From what iv heard its makes the bike very unreliable

 

Yes , you can get a lot of power from a 1200. I have ridden with those who have larger engines and except for those who have a 110 , I have very little issues with maintaining speeds with them.
As far as upgrading my 1200, I am under the impression that the engine on my baby could match theirs even more any day.

 

There are two groups of engine upgrades: 1, bolt-on; and 2, strip and machine cases. That applies to Sportys and big twins. It has been possible to bolt on bigger cylinders for 883 Sportys for much longer than the big twins, meaning the twincams. The previous Evos couldn't be increased in size that way (except for a couple of cubes).

In the case of big twins there are further options, like complete replacement engines, going way up the scale to 155" and beyond, depending on model, something not available to the Sporty owner.

So I think you are misinterpreting the situation! Also bear in mind that the majority of Harley owners do not modify their engines, just bolt on a few alternatives like air filter and pipes.