MacDizzy's Two Stroke Technology Exchange (MTSTE) - The two stroke engine capital of the internet.

Pulling Studs

A and B Cylinders

Rod Length and Rod Angle

Compression Ratio

Too Much Compression


Intake System

Over Rev

Crunching Numbers

Mossbarger Reed Cage

Break In

Sealant For Engine Cases

Spacer Plates

Pump Gas

Case Volume


Reed Valve Conversion

Mikuni vs. Keihin

Piston Thickness & Squish


Crankcase Bleeding

Hemi Head Design

Wave Tuning

Rod Bearings

Reed Petals

More Crankcase Bleeding

Banshee Reed Spacers

EGT Probe Placement

Combustion Chamber Shape vs. Ignition Advance

Ignition; Advance or Retard

More-Power Pistons


Blaster Data


Reverse Engineering

More More-Power Pistons

Porting Epoxy

Squish Angle

Squish Thickness

Just One Ring on Two Ring Piston

What to Call The Ports

Using a Piston Stop

Gasket Thickness & Squish Velocity

Boost Port


Port Texture

Texture & Punctuation?

Air, Liquids & Solids

Snowmobile Porting

Building Pipes

Porting Tools

Catch Tank

Honda Strokers

Honda TRX250R Barrels

Wiseco Pistons

Keihin Needles

TRX250R Engine Cases

Copper Gaskets

Plated Bores

Engine Displacement

Balance Shaft Clatter

Which Pipe

Engine Work

ATC250R and TRX250R Heads

CR250R Ignition on the TRX250R

Reed Cages

Divider Between E-Port and T-Port

TRX250R Transmission Assembly



How To Make Stainless O-Rings

Big Bore Considerations

Safety Wire Tips

Spacer Plate and Gasket Material

More Stroker Motors

Calculating Port Duration

Oil and Grease on Gaskets

Engine Cooling

Cutting Pistons

Adding Stroke

Honda Crankshafts

More Ignition Timing

Two Stroke Thinking


Setting Up A Stroker

Flywheel Modification For Ignition Advance

Common Stroker Errors

Determining Fuel Octane

Truing The Top Cylinder Deck

Stroker Changes

Piped Pimple Porting

Head Machining

PWC Rev Limit

General State of Tune

Cutting Ports and Tunnels


Parallel Squish & SAR

Exhaust Port Stuffer

Exhaust Ports

Using Correct 2 Stroke Terminology

Scooter Engines

Porting NiCaSil

Compression Testing

Rod Length

More Squish Info

Power Pistons Revisited

106 Pages of Updates

More Ignition Timing

The ignition timing has to be set somewhere between 1.8 mm's BTDC and 2.2 mm's BTDC. This can be accomplished by using a Hinson Adjustable counterbalance shaft holder. You can also set it that way with a CR250R ignition. You'll find that if the chamber shape is very good, the engine will run well at settings closer to 1.8 mm's BTDC. Obviously, the least amount of initial advance is best. Always. For tuning purposes you might find it helpful to know that more advance (moving toward 2.0 to 2.2 mm's BTDC) will favor bottom end power and less advance (1.9 to 1.8 or less) will favor top end power.

When using the Hinson adjusters I have found that they are more accurate than the stroker crankshafts. That is, a +5 mm stroker doesn't always have its crankpin relocated in exactly the same place. In fact it is never in the same place. Because of that I can not tell you to drop in a +5 mm stroker and set the timing to the second scribe line below neutral (or another setting). It turns out that each crankshaft must have its ignition timing set up specifically for it. Every new stroker crankshaft has to have its adjuster plate dialed in to zero. And timing marks have to be referenced on it. This insures that the engine will be running in the appropriate range by giving its owner new reference points to use when dialing in the power personality. I typically mark from about 1.6 mm BTDC to 2.1 or so mm's BTDC. Going beyond 2.2 mm's or so BTDC creates a lot of piston heat and is generally not ventured past without careful monitoring of the internals.

When the trailing edge of the flywheel trigger just passes the trailing edge of the pick-up, the spark plug fires.

MacDizzy Home | Blog Page | MacDizzy M.U.L.E. Engine Builds | MacDizzy Update 2011! | MacDizzy's Two Stroke Technology Exchange | MacDizzy Tee Shirts | Compression Ratio Chart | YFS200/DT200 Yummie Yami | YFSYZ Hybrid | Two Stroke Engines | TRX Specs | TRX Dyno | TRX 270cc Engine | TRX Intake & Shifter | Two-Stroke Software Review | Blaster Rebuild | 2 Stroke Cylinder Mapping | Basic Porting | Banshee 370 cc Long Rod | Engine Building Formulas | LT250R Melt Down | RZ500 - Old Friend | TRX Internal Discoveries | More TRX Internal Discoveries | Little L Tease | GP760 Observations | KTM

MacDizzy's Two Stroke Technology Exchange is the Two Stroke Engine Capital of the Internet.