GOLD Event: Tuning of the Carburetor

THIS EVENT IS ONLY AVAILABLE FOR FMH GOLD MEMBERS

Steve Knoble goes through a step by step process of tuning the stock Harley CV carburetor on a 1200 Sportster, followed by a rejett for a high flow air filter, and higher flow exhaust. He gives an up-close view of which screws he is turning and when, while making adjustments to the tune.

First, Steve adjusts the idle speed and makes adjustments to the idle bleed/mix screw. For fine tuning, a small adjustment is made to the idle speed again. During a test ride, there was some popping out the exhaust and stumbling at low rpms, so Steve re-jets from a 42 intermediate jet to a 45 intermediate jet, to make up for the higher flow of the air filter and exhaust. After the rejetting, adjustments are made again to the idle air bleed screw and then the idle speed screw.

An in-depth knowledge of the carburetor is a key point to the full understanding, troubleshooting, and tuning of a motorcycle engine. Because of that, Steve will break down the process in a simple manner that is easy to grasp by even a novice mechanic.

This GOLD member video centers around the 1200 Sportster, but it covers all stock carburetors for Evo Big twins, 91-99, all carbureted Twin Cams, and Sportsters 91-06. While the settings and jets are different from year to year and unique to each engine size, the operation of the parts of the carburetor are all essentially the same. Therefore, once you learn the workings of one of these carburetors, you should have the knowledge to dig into carbs from other years and models.

In other GOLD member exclusive videos, Steve covers disassembly of the carburetor, detailed description of the parts and carburetor operation, plus cleaning and tuning.

[/groups_member]