American Rail vs International Rail Engine Mounts: How to Tell What You Have (and Buy the Right Mount)
Buyer Guide: If you’ve ever ordered an engine mount and it “almost fits,” this is why. The difference is simple: rail spacing. Measure once, buy once.
Toigo Motor Mount (American Rail) | Toigo Motor Mount (International Rail) | Shop Engines & Motor Parts
Quick answer
The difference between American rail and International rail motor mounts is the center-to-center distance between the two engine rails on the chassis. Many sources summarize it like this: American is ~3" and International is ~3 5/8" (92mm). (PMC guide (PDF))
On Toigo’s product page, the American rail mount is listed as 2 7/8" c/c. (Toigo American Rail mount) The Toigo International mounts are listed as International rail mounts with a sliding top plate assembly. (Toigo International Rail mount)
What “rail spacing” means (in plain English)
Look at the two parallel rails/tubes where your engine mount clamps onto the chassis. The only measurement that matters for “American vs International” is the distance from the center of one rail to the center of the other rail.
Why the confusion? Because the engine can be American (GX/Clone/Animal style) while the chassis rails might be international spacing. The mount must match the chassis rails, not just the engine family.
How to measure your chassis in 60 seconds
- Grab a tape measure or calipers.
- Measure center-to-center of the two engine rails where the mount sits (not edge-to-edge).
- If you’re around 3" (or Toigo’s listed 2 7/8" c/c for American rail), buy an American rail mount.
- If you’re around 3 5/8" (92mm), buy an International rail mount. (Common standard explained in the PMC mount guide)
Tip: If you’re between measurements or your chassis has unusual tubing, measure twice and look at where the clamps actually land.
Which Toigo mount should you buy?
Buy American Rail if your rails match American spacing
Toigo’s American rail option is listed with American clamps and 2 7/8" c/c rail spacing. It includes a slider plate assembly. Motor Mount with Slider Assembly (American Rail)
Buy International Rail if your rails match International spacing
Toigo’s International rail mounts are listed as 15 degree International rail with a sliding top plate assembly. Stealth Motor Mount (International Rail) (You’ll also see the same International rail description on other Toigo mount listings, like Wraith.) Wraith Motor Mount (International Rail)
Toigo engine mount options at a glance
Prices below are what the product pages show right now. They can change, so confirm on the page.
- Motor Mount WITH Slider Assembly Complete, American Rail: $168.25. Listed as a 15 degree mount with American clamps, steel clamps only, engine rail 2 7/8" c/c.
- Stealth Motor Mount WITH Slider Assembly Complete: $168.25. Listed as a 15 degree International rail mount with a sliding top plate assembly.
- Wraith Motor Mount WITH Slider Assembly Complete: $168.25. Same International rail description.
- Motor Mounts, 15 degree with 1/2" standard plate, International clamps: $86.15. Comes with a standard 1/2" plate and a steel clamp set.
Replacement and add-on mount parts
You do not always need a whole new mount. If you are refreshing or repairing what you have, these individual parts are listed:
- Motor Mount Slider Assembly Only (two slider plates only)
- Motor Mount Top Slider Plate (the plate the engine attaches to, includes 4 studs and 4 nuts)
- Motor Mount Clamp Set (billet steel clamps for International rails)
- Motor Mount Bolt Kit, Slider Flange Nut and Motor Mount Stud
After the mount is on: alignment and slide adjustment
A slider plate lets you move the engine forward and back, which is how you set chain tension and line the clutch up with the axle sprocket. Any time you move the slide or change sprockets, recheck alignment before you run.
- Loosen the slider nuts, move the engine, then tighten them evenly and recheck.
- Look down the chain line from the clutch to the axle sprocket. Our alignment guide and chain guide cover tension and alignment.
- If you change gearing, revisit the slide position. See the Outlaw Kart Gearing Guide.
- Check that the throttle linkage still moves freely after the engine shifts. The throttle pedal, cable and linkage guide helps here.
Swapping engines or buying a used kart? The engine classes guide and used kart inspection checklist are worth a read first.
Common mistakes (and how to avoid them)
- Measuring edge-to-edge instead of center-to-center: center-to-center is the standard described by kart mount suppliers.
- Assuming “American engine” = “American rails”: the chassis rail spacing is what matters for the mount.
- Not checking slide/adjustment needs: slider plates help with chain alignment and gearing changes.
Frequently Asked Questions
What is the difference between American rail and International rail engine mounts?
The difference is the center-to-center distance between the two engine rails on the chassis. Many kart suppliers describe American as around 3" and International as around 3 5/8" (92mm).
What rail spacing does Toigo list for its American rail mount?
Toigo’s American rail mount listing states Engine Rail 2 7/8" c/c. It comes with American clamps and a slider plate assembly.
How do I measure my kart chassis for an engine mount?
Measure center-to-center between the two engine rails where the mount sits, not edge to edge. Measure twice, and check where the clamps actually land if your chassis has unusual tubing.
Does an American engine need an American rail mount?
Not necessarily. The mount has to match the chassis rail spacing, not the engine family, so a Clone or GX-style engine can sit on a chassis with International rails.
Which Toigo engine mount fits a Stealth chassis?
The Stealth Motor Mount with Slider Assembly Complete is listed as a 15 degree International rail mount with a sliding top plate assembly. Measure your rails first, and call the shop if you are unsure about fitment.