Types of Banshee Engine Builds

It can be overwhelming to choose the engine components that will work well together and that deliver the performance you want. Re-Do Banshee can help you come up with a solid plan for your engine build or re rebuild.

There are a lot of options and variations on engine rebuilds and performance engine builds. We have grouped engine builds into 3 main categories to make it easier to discuss the differences.

Standard or Stock Engine Rebuilds

Standard Bore Engine = 64mm and is 347cc.

Stock Engine Rebuild = If an engine has worn or damaged stock cylinders, the top end of the engine can be rebuilt or repaired by boring the cylinders slightly larger than stock and installing larger pistons. 

  • 350-375 cc Stock Cylinders = 64.25mm - 66.5mm bore on a stock stroke (54mm) crankshaft. A stock crankshaft or an aftermarket stock stroke crankshaft can be used. Stock cylinders are bored larger than the stock 64mm bore. Displacement varies depending on how large the stock cylinders are bored to. This engine build is often done as a rebuild to repair the stock engine. 

A stock engine rebuild can be done a few times over the years if needed. The engine will still perform as a stock engine or slightly better, and can still have a lot of life left in it. 

Small Bore Engine Builds

Small Bore Engine = 64mm - 66.5mm. For increased performance, stock cylinders can be over bored (bored over stock diameter), and additional performance parts can be added. For more performance, an aftermarket cylinder kit can replace the stock cylinders, along with other performance parts, which might include a +4 mil crankshaft.

Small Bore Engine builds can be built with stock engine cases or Driveline Performance cases.

Some common small bore engine builds are:

  • 347 cc Assassin-2 Cylinders = 64 mm bore on a stock stroke (54mm) crankshaft. 
  • 385 cc Stock, Serval, or Cheetah Cub Cylinders = 65 mm bore on a +4 mil stroke (58mm) crankshaft.
  • 392 cc Assassin-2 Cylinders = stock stroke (54mm) crankshaft.
  • 397 cc Stock, Assassin-2, Serval, or Cheetah Cub Cylinders = 66 mm bore on a +4 mil stroke (58mm) crankshaft.
  • 403 cc Stock Cylinders = 66.5 mm bore on a +4 mil stroke (58mm) crankshaft. This is the biggest small bore engine you can build using a +4 mil crankshaft. This can be a stepping stone on the way up towards a Big Bore Engine Build. 

Big Bore Engine Builds

Big Bore Engine = 68 mm or larger. 

For +4mil engine builds, stock engine cases can be easily used. For +7mil or +10mil builds, a Driveline Performance engine case is recommended for strength and reliability. We often recommend a +10 mil over a +7 mil crank because there is not much price difference.

Some common big bore engine builds are:

  • 421 cc Assassin-2, Serval, or Cheetah Cub = 68mm bore on a +4 mil stroke (58mm) crankshaft.
  • 465 cc Serval or Cheetah Cub = 68mm bore on a +10 mil stroke (64mm) crankshaft.
  • 472 cc Serval or Super Cheetah Cub = 72mm bore on a +4 mil stroke (58mm) crankshaft.
  • 521 cc Serval or Super Cheetah Cub = 72mm bore on a +10 mil stroke (64mm) crankshaft.
  • 611 cc Cheetah DM = 78mm bore on a +10 mil stroke (64mm) crank. (This is 611.63 cc, so it shows on our engine displacement chart as 612 cc)

Re-Do Banshee can help you with any of these engine builds. We can help you select the parts for your DIY build, or we can rebuild or build your engine based on the plan you agree on with our help. 

For more detailed information about engine cylinders, check out these blog articles:


Back to blog

Do You Have a Project?

If you have a Banshee to restore, want to upgrade your suspension, or are planning an engine build, we're happy to help.

We specialize in Yamaha Banshees. If you have a different project in mind, contact us and we will let you know if we can take it on and what you can expect. 

CALL 📞📱 or message us at 541-419-6054. 

We offer a range of services. We can:

  1. Help you select parts for your DIY build.
  2. Help you Pack and Ship your Engine to us, build your engine, then ship it back to you to install.
  3. Complete the engine build for you and install in your Banshee.
  4. Inspect, repair and service the whole Banshee for you.
  5. Build or restore your Banshee.
  6. We may also be able to locate a local Banshee for you - then install your newly built engine in it.

Project References:

  • We calculate engine displacement based on the bore in the engine's cylinders and the stroke length of the crankshaft. Click here for more explanation in our Banshee Engine Displacement blog article. 
  • Click here for information about Banshee engine break-in procedures. This includes our recommendations for Fuel to Oil Ratios and Selecting the Correct Fuel.

About the Authors:

This project article was written by Janel with plenty of help from Virgil. Virgil is the Banshee mechanic, and I am the website mechanic. I do own and ride a Banshee, which helps. 

The Re-Do crew hopes sharing our project info and specs may help some with their own projects, or that you find it interesting. I want our technical info to be accurate and helpful.

Please do let us know if you like our project articles, or if you think I need to correct something. You can send an email to info@redo-parts.com - and your comments will be passed along to me. 

Thanks ~Janel 😉👌