Lowbrow Customs Sportster 1200cc Kit
Welcome to 1200 cc’s, baby.
Photos: Ed Subias
We all know the Harley-Davidson Sportster 883 is a rather light bike for a Harley but has power issues compared to most of the big bikes we ride. This can be an issue until some sort of power improvement has been made through the many 1,200cc “big bore” kits that are available today. We have seen many kits at all different price ranges, and yet they all seem to do the exact thing: give you larger pistons and cylinder heads without any case boring to get the job done. After doing some homework we found a kit that Lowbrow Customs sells for right around $500 and comes with everything you need to up those ponies on that 883 Sportster of yours. Each kit comes with pre-fit cylinders and a set of Wiseco 9.5:1 compression pistons, matching Hastings piston rings, head gaskets, and a pair of base gaskets. Yes, that’s a lot of parts for the money. Follow along and see if it was worth the savings or not.
We took our well-worn Sportster tracker to Scotty’s Speed Metal & Fabrication for the motor hop-up.
Photos: Ed Subias
Here is a shot of the Lowbrow Customs kit fresh out of the box and ready to be installed.
Photos: Ed Subias
Scotty starts the big-bore kit swap by getting rid of the gas tank and other parts that are in the way.
Photos: Ed Subias
Scotty also takes off the Mikuni carburetor and air filter.
Photos: Ed Subias
The custom Leo Vince pipe and muffler was next to be removed.
Photos: Ed Subias
Scotty removed and inspected the spark plugs before digging into the motor.
Photos: Ed Subias
The rocker boxes were removed as to gain access to the pushrods.
Photos: Ed Subias
The removal of the stock heads are required to get to the cylinders and pistons.
Photos: Ed Subias
And off come the “jugs” also known as the cylinders.
Photos: Ed Subias
Scotty then removes the pistons from the connecting rods and cleans the engine cases.
Photos: Ed Subias
As you can see, these grimy pistons have seen some better days.
Photos: Ed Subias
Scotty and his son Luke first inspect the Lowbrow Customs kit before installation.
Photos: Ed Subias
Pre-fitting, measuring, and inspecting the piston and rings against the cylinder walls is a must when installing any big-bore kit.
Photos: Ed Subias
Once everything checks out to be good, Scotty installs the new pistons.
Photos: Ed Subias
Then the new base gaskets and 1,200cc cylinders…
Photos: Ed Subias
…go onto the Sportster’s engine cases.
Photos: Ed Subias
The stock heads and pushrod tubes go back on the bike.
Photos: Ed Subias
Scotty carefully installs the stock pushrods back into the bike as well.
Photos: Ed Subias
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The stock Sportster rocker boxes are also fitted and tightened to factory specs.
Photos: Ed Subias
New seals are outfitted to the intake manifold before reinstallation.
Photos: Ed Subias
The Mikuni carburetor is checked for wear and then reinstalled.
Photos: Ed Subias
All the other parts—such as the gas tank, spark plugs, spark-plug wires, and ignition—are then put back on the bike.
Photos: Ed Subias
After the air cleaner is replaced with a K&N, Scotty installs the H-D ham can cover.
Photos: Ed Subias
And we were done. More horsepower for not a lot of money!
Photos: Ed Subias
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