GP460 Engine...

Discussion in '2-Stroke Engines' started by Wheres my dog, Jul 5, 2010.

  1. Wheres my dog

    Wheres my dog New Member

    Hello All,

    A few questions about the GP460 engine if I may...

    How is it in terms of reliability? (site search did not really give anything)

    How loud is it idling and while under load? (maybe compared to a Honda or EHO35)

    As always, thank you for the information!

  2. 5-7HEAVEN

    5-7HEAVEN Guest

    I would not rate this engine well in terms of reliability, so far. There's not much meat near the bellhousing bolt holes. I cracked the housing from overtightening. On one engine, the bellhousing threads pulled thru, and I was only using the ratchet with one hand. Also burned a piston at high speed, which could've been my fault.

    Loudness is subjective. My friend Rick's 460 is VERY quiet, using a Happy Time stock muffler. I had a new 460 with stock muffler; Rick's engine was quieter than mine. It depends which exhaust you use. With a Dominator pipe, it's very loud. With an ADA S1 pipe, it's quieter than a stock muffler. With my present SBP Happy Time expansion pipe, it's even quieter.

    Under load, it's louder, but not SUPER loud like a Tanaka 47R. That sucker's got a LOUD exhaust at high rpm! With the 460, high speed engine noise is bearable, especially with a shift kit. Engine noise lessens as you shift to a higher gear.

    Hope this helps. This engine is noisier than your Honda or Subaru, but it's also 2.625 times as powerful, 1.6hp as compared to 4.2hp!

    Hope this helps.
  3. 5-7HEAVEN

    5-7HEAVEN Guest

    Clutch springs fail on a regular basis on GP460 engines. I broke a spring on a 25-mile round trip ride on Tuesday. The engine would not idle at a stop, because the clutch was engaged. I was able to limp 2 miles homes by timing the traffic lights and feathering the throttle at stops.

    I am replacing the GP460's OEM clutch with a pocketbike clutch. It fits after simple modifications and costs $7, compared to $50-something for the 460 clutch and an extra $15 for the low-rpm clutch springs. The pocketbike clutch is velvet-smooth, placing less stress on the drivetrain. The 460's clutch grabs in a brutal manner.

    The GP460's loudness can be cured by installing a Happy Time muffler. My friend Rick bolted a stock HT muffler on his 460/Staton chain drive w/NuVinci hub. He likes it, and it's quieter than stock.

    I installed an SBP expansion pipe that was designed for Happy Time engines. Except for the rectangular port and the round exhaust flange mismatch, it's an excellent fit. The noise is much quieter than Rick's muffler. It is so quiet that you can hear engine noises other than the exhaust. The extra power throughout the entire range is amazing.
    Last edited by a moderator: Jan 9, 2011