POLARIS ACE ENGINE GY6 150cc or 175cc
DIRECT GUARANTEED FIT FOR POLARIS ACE 150cc
New GY6 150cc Internal Reverse Buggy Go-Kart Engine. This is the exact replacement engine for your vehicle.
BDX 150CC GY6 ENGINES ARE GUARANTEED, VERIFIED AND CERTIFIED TO BE 150CC ENGINES:
WARNING: If you are considering purchasing a GY6 engine from eBay, Amazon or any other USA seller you could receive a 125cc engine instead of a 150cc and you would never know it. Since 2006 China has a history of sending GY6 125cc engines in place of GY6 150cc engines. The engines look identical from the outside. BDX Performance is the only engine seller in the USA who disassembles and visually inspects engines to ensure that they are 150cc. We unbox and dissemble approximately 50% of every engine shipment that we receive as we convert these into 175cc engines. And we have caught some engines that are GY6 125cc being sold as GY6 150cc--see below. Don't play Russian roulette with your money. Get a guaranteed, verified and certified GY6 engine from BDX. The cylinder on the left is an actual cylinder that we pulled off of an engine that we purchased as a 57mm GY6 150cc engine and was actually a 52mm GY6 125cc engine.
YOU HAVE PERFORMANCE OPTIONS WITH THIS ENGINE--SEE BELOW
Option 1: Includes the standard engine with standoff for muffler. No kick start to interfere with your exhaust!
Option 2: Includes the standard 150cc engine and a new American made high performance Uni-Filter air filter ensures clean air to your engine. See why a NEW Uni-Filter is MANDATORY for ALL new engines. Don't get an engine without one. Your new engine warranty applies only if a new uni-filter is purchased with this engine.

Option 3: - 175cc Engine, performance transmission plus all items from Options 1 and 2:

High Performance Transmission for Better Power Transfer to the Wheels:
This option includes High Performance Transmission: 1500 PRM Spring and 10 gram rollers, performance variator and high stall clutch and thus more torque and more power due to more efficient power transfer. See price options at the top of the page.
Four sets of roller weights for you to optimize top end speed and low end torque of your vehicle (9g, 10g, 12g and 14 grams). One set is included inside of your engine.
We convert your new 150cc engine into a 175cc racing engine. See price options at the top of the page.:
MORE CC MEANS MORE POWER
Read our article on how displacement relates to more power.
How big bore kits & strokers work
TAKE A LOOK AT THIS COMPARISON
Stock GY6 Hill Climb
BDX 184cc GY6 Hill Climb
We disassemble your engine, bore the case to make it larger so that we can install a 62mm big bore piston and cylinder. Then we re-assemble and test your engine.
OPTION 4 175cc Engine Plus Performance Exhaust and all items from Options 1, 2 & 3:

OPTION 5
We can rebuild your engine. Call us!
Be sure to read our article on how displacement affects your power.
IMPORTANT NOTES
[*] 60 Day Parts Warranty
Please read the Warranty details in warranty section
Engine is shipped DRY with no oil.
Be sure to add 750ml of 10w40 to the crankcase and 120ml of 80w90 to the gearcase before starting.
Important
- Adjust valves after break-in period.
- Change oil after break-in period.
- Engine is shipped DRY with no oil. Be sure to add 750ml of 10w40 to the crankcase and 120ml of 80w90 to the gearcase before starting.
- Do not use synthetic oil in GY6 engines
- Install a uni-filter with new engine for longer life and better performance. If you don't you are guaranteed to be putting dirt into your clean NEW engine. Stock air filters do not effective filter air and are the number one engine killer for GY6 engines.
Guaranteed Fit - No returns on engines.
Before ordering please call and speak to our technician if you have any questions regarding fitment. Please do not return your engine--call us if you ordered the wrong engine without consulting our technician. In the very rare event that there is a warranty issue please see warranty section.
About Oil Coolers:
Our engines Do NOT come with provisions for oil coolers. We've always advised strongly against the use of oil coolers on the GY6. We've seen too many instances where a cooler line bolt vibrated loose, dumping all of the engine oil and causing a massive failure. The perceived benefit isn't worth the risk. Oil coolers on the GY6 solve a problem that doesn't exist. Follow regular maintenance intervals, invest in a UNI Air filter (and keep it oiled), and your new engine will last many years even decades--we've seen it many times. Coolers provide a false sense of longevity benefits, and the only proven result is the added risk of unexpected massive failure.