Ring Set, GX390, Tier 3 (T3), 1.2 mm Thick : Genuine Honda

OEM Honda, Choice of Bore Size



Ring Set, GX390, Tier 3 (T3), 1.2 mm Thick : Aftermarket Replacement (Chinese)

Aftermarket Ring Set for GX390s with 1.2mm Top Ring, Std Bore Only.



Piston, GX390 Flat Top, Aftermarket, T2 Style (Thick Ring)

88mm Aftermarket Flat-top Piston for bore GX390s only.

Pistons has approx. .020 shorter compression height. However, they will still raise the compression approx .5 points.
Use our new +.040 longer rod and compression will raise and addition .5 to 1 point (depending on how much head is milled).

Flattop, .040 longer rod, .010 Head Gasket, & Mill head .050 will yield approx. 12.5 to 1

Uses 2.0,mm thick style Honda Rings.

Rings & Wristpin Included.



Piston, GX390 Flat Top, Aftermarket, T2 Style (Thick Ring)

88mm Aftermarket Flat-top Piston for bore GX390s only.

Use our new +.040 longer rod and compression will raise and addition .5 to 1 point (depending on how much head is milled).

Flattop, .040 longer rod, .010 Head Gasket, & Mill head .050 will yield approx. 12.5 to 1

Uses 2.0 thick T2 style Honda Rings.
Rings and Wrist pin Included



Piston, GX390 Flat Top, Aftermarket, T3 Style (Thin Ring, Shrt Skirt)


88mm Aftermarket Flat-top Piston for bore GX390s only.

Pistons has approx. .020 shorter compression height. However, they will still raise the compression approx .5 points.

Use our new +.040 longer rod and compression will raise and addition .5 to 1 point (depending on how much head is milled).

Flattop, .040 longer rod, .010 Head Gasket, & Mill head .050 will yield approx. 12.5 to 1

Uses 1.2mm thick UT1 style Honda Rings.
Not Included, Order separate.



Piston, 90mm for 420 Predators & GX390 Type Engines

D90mm Aftermarket Flat-top Piston for big bore GX390s. Fits stock bore on 420 Predators.

GX390s Blocks can be bored to accept this piston
407cc using stock crank,
433 with +.160 Stroker Cranks,
440cc with .200 Crank

Includes Piston, Rings, Pin, and Clips.



PRing Set, 90mm GX420

B90mm Rings set for Chinese OHVs.



Ring Set, 92mm for 13/15hp Chinese OHVs (Cast Piston)

92mm Rings set for Chinese OHVs. Fist Cast Pistons only

Will not fit Forged Piston.




Piston, GX390 Forged Flat-Top, drop In design

Forged Flat-Top to fit GX390s (and UT2 GX340s). Stock bore uses factory compression height & stock wrist pin dia so it will drop in using a standard length rod. No cutting of piston.

New style Pistons have valve reliefs for high lift cams.

Piston will provide approx. 1 to 1.5 points increase in compression. Can be used with our .040 longer rod for even more increase

Designed to use OEM Honda piston rings Part# 13010-Z5R-004 or 13011-Z5R-004 for .010 over

Wrist pin and clips included, rings are not included!



Piston, GX390 Forged Flat-Top, Stroker Applications


Forged Flat-Top to fit GX390s (and UT2 GX340s) using ARCs +.200 stroker crank.

Std bore piston with a .050 shorter compression height that when used with a stock length rod allows use of .200 stroker crank without cutting top of piston.

Pistons have valve reliefs for high lift cams.

Designed to use OEM Honda piston rings Part# 13010-Z5R-004 or Aftermarket 1301X-Z5R-CLN

Wrist pin and clips included, rings are not included!



Piston, 420cc OHV & Predator (90mm), Forged Flat-Top (w/rings)


Forged Flat-Top to fit 420cc 13/15hp GX390 Clones, 420 Predators, & +.080 over GX390s

90mm bore piston (+.080 for GX390) with standard compression height. Use with +.040 rod for maximum compression.

Rings, Wrist pin, & Clips included

Note: Actual Piston does not have Valve Reliefs in it.




Forged Piston & Long Rod Combo for GX390s

Forged Flat top and Long Billet Rod combo
DROP IN KIT - NO CUTTING or HONING REQUIRED (w/ 4.450 rod)!
This kit can produce over 1 hp more than the stock rod. Kit uses special length rod and custom piston so that it fits a stock bore 390 without any machining or boring. Brings piston to zero deck height.

Includes Piston, Rod, Rings, Bearing, & Wristpin
Piston: Diamond Forged Flat-top
ARC 3.450 Rod
Bearing: Tri Metal
Rings: Chrome Moly 3 pc
Wristpin: HD Tool Steel
(Note: On used blocks, a light hone may be needed for proper ring seat & bore must be straight)
Warning: You must have a at least .020 between head and piston.



Piston, 92mm for 460s & GX390 Type Engines, Forged, Domed w/rings

Our lightweight flat-top domed piston is the perfect upgrade for your 92mm bore clone engine (440 & 460). This piston along with a billet rod will complete your bullet-proof engine build. Add reliability and horsepower to an already strong platform.

This is a flat top piston and will increase your compression!

Manufactured in the USA by Ross Racing Pistons

Rings, wristpin, and clips included.



Piston, 92mm for 460s & GX390 Type Engines, Forged, Flat-Top w/rings

Our lightweight flat-top forged piston is the perfect upgrade for your 92mm bore clone engine (440 & 460). This piston along with a billet rod will complete your bullet-proof engine build. Add reliability and horsepower to an already strong platform.

This is a flat top piston and will increase your compression!

Manufactured in the USA by Ross Racing Pistons

Rings, wristpin, and clips included.



Ring Set, 92mm, For Forged Piston

92mm Rings set for Forged Pistons

Will not fit Cast Piston