Teryl reached out to Re-Do Banshee after his engine suddenly started running poorly. Virgil’s first recommendation was simple: start with a compression test. Teryl grabbed a tester from Harbor Freight (or a nearby store) and checked the numbers. One cylinder came in at 150 psi… but the other showed only 40 psi. A big drop — especially on just one side — is a clear sign of piston or cylinder damage.
Wanting to get it fixed right, Teryl ordered a shipping box from Re-Do Banshee and sent his engine in for a full diagnosis. He had been told it had a 4-mil crankshaft, and Virgil was able to confirm that once it arrived. After Virgil confirmed damage to one of the pistons and cylinders, Teryl made the decision to upgrade to a full 421 Serval build.
Virgil got the parts ordered, assembled the 421 with no issues, and completed the heat-cycle process in the shop. Then the fresh engine was shipped back to Teryl in Ohio. Once installed in his Banshee, he went out for a ride and did a plug chop to dial in the jetting.
Not long after, Teryl called to share the good news: his Banshee rips. Tons of power. Runs amazing. He’s thrilled with his new 421 Serval build — and that’s what we love to hear! Woohoo! 👍🙂
For more info on Teryl's build:
- Watch the video. 👀
- Scroll down ⬇️ for the link to watch the build's whole playlist on Youtube.
- Keep scrolling down ⬇️ to see the build specs below the video.
Video Coming HERE Soon!!
| Q- Have questions about selecting parts or getting help with your build? A- You can call 📞📱 or message us at 541-419-6054. |
We are flexible and will work with you. We can:
- Help you select the parts for your DIY build and ship them to you. - OR -
- Build your engine and ship it to you to install. - OR -
- Complete the whole build for you and install your engine in your Banshee.
Teryl's Engine Specs
- BUILD NAME: Teryl's 421 cc Serval Build
- DISPLACEMENT: 421 cc
- CYLINDERS: 68 mm Serval Cylinders - from Cast Precision Industries, or CPI.
- PORTED: As Cast. This means they are untouched from the casting at CPI.
- PISTONS: Wiseco 68mm
- CYLINDER HEAD: Redline Racing Cool Head
- DOMES: 22 cc
- CRANKSHAFT: Came with a HotRods 58 mm stroke. This is +4 mil over the stock stroke of 54 mm. Crankshaft was already trued and welded.
- COMPRESSION: 150 psi
- REEDS / CAGE: Mototassinari V-Force 4 Reeds and Cage
- CARBS: Keihin 35 mm PWK
- CARB JETTING: Started with 170 main jets and 50 pilot jets at our shop. Teryl will do a plug chop to determine final jetting.
- NEEDLES: CEL
- AIR SCREW ADJUSTMENT: 1.5 turns out
- FUEL RECOMMENDATION: Premium Non-Ethanol Gas (91-94 Octane)
- WATER PUMP IMPELLER: OEM
- CLUTCH: Modquad Lockout Clutch with Cover
- EXHAUST: Shearer Big Bore In-Frame pipes with Shearer silencers.
- TIMING: Set to 4 degrees advanced