1991 Harley davidson police special help
 

The starter on my bike went and when I went to order a new one it's asking me what model police bike can anyone tell me what that is I enclosed a pic also what size is the engine

80 cubic inches unless it's been modified. I looked at your picture again and it doesn't appear as if it has been modified. it looks like the original rivets are still in place for the nosecone.

Try decoding the VIN:
https://www.hdforums.com/forum/vindecoder.php


or looking at the parts finder:
http://www.stcharlesharleydavidson.c...%7e1OF2%5cDF91


Also when using the parts finder it lists 2 Police models - DA & DF - the 5th & 6th characters of your vin. You can also post in the EVO section of the forum.
https://www.hdforums.com/forum/evo-classic-models-84/

Who are you ordering from? Any good HD parts person should have asked for the VIN if you were in doubt. They cal pull it up, tell you the date it was assembled, model, engine, color, and where it was originally sold.
Getting a starter shouldn't have been an issue.

As for model that is the FLHS (Electra Glide Sport). I see it has police saddle bags but as mentioned you can decode the VIN to see for sure what it started out as.

This should be the one but, double check me on it.
http://www.boardtrackerharleyonline....nted-31553-90a

https://cimg8.ibsrv.net/gimg/www.hdf...74f2d376f6.jpg

https://cimg0.ibsrv.net/gimg/www.hdf...ae7c688d1f.jpg

I had the same year and model bike. I purchase it from the New York City Police Department's auction. It a FLHTP with a 80 cu.in. EVO motor.