i was wrong about the size its an 88ci not 80. heres the email i was sent about the numbers on the engine.

Mr. Walker,

Thank you for sending me your crankcase serial number. I believe the number is actually c03613. The first letter is a year code, the letter C identifies this as a 2002 model engine. The second letter indicates which crankcase is used. The letter “o” is not used by S&S in this format. Therefore, I will assume that the letter “o” is a number “0”. When no second letter is used in the serial number, this tells me that it is a 3 ½” or 3 5/8” bore crankcase.

Thus, using serial number C03713, what you have is an 88” evolution engine built for Indian Motorcycle Company out of Gilroy, CA. It has a 3 5/8” bore and a 4 ¼” stroke. This series of Indians were built from 1999 to 2003 until the company went bankrupt. This engine was sold in a large batch unassembled to Indian so I have little detail regarding the true configuration of your engine. Many of these engines were built to meet strict California emissions standards. Your carburetor may be set up to run lean to meet these emissions standards which consequently hinders the engine’s performance. Inspect the jetting on the carburetor. You may need to richen it up. I would expect you to need around a .072 main jet and a .0295 intermediate jet for optimal performance. Of course this is just a starting point and you may find that the bike is happier with a different configuration. Secondarily, your cam shaft is probably pretty mild. You can really unleash your engine’s performance by upgrading to a .561 cam. This is a bolt in cam that would require no head work. Part number for the cam is 33-5076.

I own a 2002 Indian Scout with the same engine and I love it. I ride like a maniac and the engine takes a beating. The limitation of this engine is that you can do very little to build it up. There are no parts available to increase your engine’s bore so the only way to increase displacement is to stroke the engine. A 4 ½” stroke would take this engine to 93” and a 4 5/8” stroke would make 96”.

Chris Clemens

Technical Support

866-244-2673, ext. 1277