The Procedure

To perform the Big Bore Kit upgrade we will need your bike’s existing cylinders. Your cylinders are bored out and re-sleeved with ductile steel sleeve inserts. The Kit includes Head Gaskets (116” Kits will also include Base Gaskets), as well as one set of High Compression Pistons at the appropriate bore size (complete with wrist pins, clips, and rings).

We recommend the following additional components/services to ensure maximum output:

  • LLOYD'Z Variable ClutchLLOYD’Z Variable Clutch
    We will modify your existing Clutch Hub to accept our Variable Pressure Plate. The enlarged pressure plate features six hinged weights along the outer perimeter, adding the clutch force required to ensure proper power delivery to the rear wheel. Your Primary Cover will be milled to provide clearance for variable clutch fitment.

    Variable Clutch:
    Primary Cover Clearancing Service: $55.00


  • LLOYD’Z Performance Headwork
    We will perform a 3-angle Valve-Job with bowls & Seats blended, the ports glass beaded, de-greased, and milled.

    Performance Headwork Service:


  • LLOYD’Z Big Bore Cam Profiles
    We recommend HOH-504 for Vision & Cross-Country models, and HOH-506 for 2009-and-newer steel-frame cruiser models. Your bike’s cam carriers and rear carrier’s exhaust rocker require modification to allow clearance for camshaft fitment. Either cam profile also requires the use of a high-lift valve spring kit. 2008-and-earlier Steel-frame cruiser models will also require a cam carrier upgrade kit, this kit will replace your existing carriers with 2009-and-newer style carriers.

    Big Bore Kit Cams:
    Cam Carrier Upgrade Kit: $299.95 (only required for 2008-and-earlier models)
    Cam Carrier & Rear Rocker Clearancing: $55.00


  • LLOYD’Z ECM Reflash Service
    Our ECM Reflash Service will remove your speed limiter, raise your rev limiter to 6400 RPM, and also includes a brief optimization of your bike’s timing curves.

    ECM Reflash Service, 2007-and-earlier models:
    ECM Reflash Service, 2008-and-newer models: $225.00

Additional Requirements:

Your bike will need to have a Power Commander 5 installed for fuel/timing adjustment purposes, and will need to be dyno tuned. The bike will need to undergo a 500-mile break-in period prior to dyno tuning.

If we perform the installation, 300 miles of the 500-mile break-in period will be added to labor costs.

Depending on your year/model we may be able to provide a base map for the break-in period, we do not recommend using the base map beyond the break-in period. We generally do not recommend the use of pre-made PCV base maps altogether as all bikes will vary to quite a significant degree, so there is no way to guarantee the functionality of any map that was not created on your exact bike with your exact mods installed.

Please note that this kit was intended for installation by trained professionals – please verify that you are comfortable with/able to perform the installation procedure before beginning, we cannot be held responsible for any issues caused by improper installation/operator error

While we have not run into any reliability issues with our Big Bore Kits, one area that you will want to pay attention to is your warm-up procedure – Before riding a bike with one of our Big Bore Kits installed, you need to make sure that you allow the bike to reach proper operating temperature (as with a stock bike). We cannot be held responsible for any issues caused by an improper warm-up period. If storing the bike for extended periods in humid environments, we recommend using a marine motor fog spray before storage.