I am looking to upgrade my 883 to a 1200. Besides having the conversion done to the engine, is there anything else that anyone suggests should be done or is required to be done ? Do I also do a Stage 1 upgrade? Change the exhaust, etc.? I am obviously a novice to this so any suggestions would be very helpful. Thanks.

 

I suggest you search the Sporty forum using '1250', to see recent threads on upgrading from 883. Essentially there are two ways: buy the Harley kit; or buy an aftermarket one. The Harley kit includes new heads, so is expensive. Aftermarket kits are designed to work with your 883 heads, so come in much cheaper. A popular kit is a 1250cc conversion, available from various suppliers, including HDF sponsor NRHS Performance.

The Harley kit simply increases capacity and will give you an engine identical to a stock 1200. The aftermarket kits raise compression ratio and will give improved performance over a stock 1200. An aftermarket air filter plus change of exhaust will get the best out of the upgrade, for which you will also need a tuner box.

Do a bit of armchair research as suggested, plus look at NRHS's website, for more info!

 

Thanks grbrown. I appreciate the guidance.

 

I have read a lot about the 1200 and 1250 conversion. I did a 1200 conversion years ago myself. What I haven't seen or read is any proof that one conversion is better than the other.

To me, the differences lie mainly with cost. The HD 1200 conversion kit basically gives you the same motor setup as a factory 1200. If you install the 1200 kit yourself you can install your own tuning kit. Properly installed this will ultimately give you a better running bike than if the HD dealer installs it because the dealer is required to download the EPA mandated flash.

NRHS has an excellent reputation. Their customer service is top notch. That's part of the buying experience. I'm not convinced that the 1250cc conversion kits is superior than the HD 1200cc kit. I think the 50cc difference is primarily a way to differentiate it from a standard 1200cc kit. I think bother offer a high quality upgrade to a stock 883. The positive of the 1250cc is that it is about 1/3 cheaper because it uses the stock 883 heads and valves and not the 1200 heads. Again a good tuner kit is needed with this 1250.

I haven't seen proof that a properly installed 1250cc or a properly installed 1200cc is better than one over the other. What I do think is that dealing with NRHS (or companies like Hammer) will probably give you much better customer service and a better buying experience. Especially if you'll install it yourself or even have an indy do the work. The HD dealer install option gives you a stock 1200 bike with the lean running EPA tuner without the ability to adjust it without buying another tune kit yourself anyway. Oh, the dealer WILL charge you for the EPA tune download.

IMHO the choice is yours.

 

Thanks Guys, the help is much appreciated. Ive begun my armchair research as grbrown suggested and am beginning to understand the conversion process. I am concerned that if I go with the 1250 instead of the HD that I will not be covered under the warranty for any issues. So I definetely have to find out for sure about that before making my final decision. Also, I saw in one of the old 1250 thread something about changing the gear ratio or gears to a 30T. Guess I need to research this as well.

 

Are there any dyno numbers with different tunes on these 1250 kits?

 

A larger sprocket comes in the Harley kit I understand. Frankly I wouldn't change gearing as these bikes are high geared to help them get though EPA noise tests. Using 883 gearing on a 1250 adds to the fun!

 

That is true I have talked to my dealer but my next question is what tuner do you recommend for these 1250 kits? I'm running a 2011 Iron 883

 

K thanks for the info I will call when I pull the trigger for the upgrade Sorry to high jack this thread

 

I don't or won't disagree with you in absolute terms. I believe everything you say about your 1250cc kit. What I don't see is the differences in practical terms. There are many stock 1200cc Sportys that run 50k, 60k, even 100k miles when properly maintained. What you get with the HD 1200 conversion kit is a factory 1200.

While I believe your kit uses forged pistons and lined cylinders, how is that quantified compared to the 1200? What are the power differences of your 1250cc kit with stock 883 heads and stock cams vs the 1200cc kit with the 1200 heads and stock cams? Assuming both get a proper tuning.

When choosing I would choose your NRHS kit. Mostly because you help all of us out, take the time to heal with us, offer a quality kit and the cost is beneficial. So my post isn't anti-1250. It's more about trying to get a practical answer. There are many reasons to choose the 1250. I'm just not sure a significant power difference and better overall reliability vs a similarly setup 1200 are the reasons.

If I'm wrong I would certainly like to learn about it.

As for the sprocket? Changing out the stock 883 sprocket to a 1200 sprocket is a personal choice. The 883 offers better bottom end acceleration but revs higher at highway speeds. The 1200 gives up some bottom end grunt for lower revs at highway speeds. Your driving style will determine which you'll prefer.