KartFab
Active member
The gx390 Mano I have was stock stage 1 believe it or not. I upgraded a few things on it like 280 cam and connecting rod, but other than that it was stock. It actually was a very mild build.
The gx390 Mano I have was stock stage 1 believe it or not. I upgraded a few things on it like 280 cam and connecting rod, but other than that it was stock. It actually was a very mild build.
Did you have problems shredding belts? If I was going to build a big block it would probably just be Stage 1 with billet flywheel/rod, thin head gasket and a timing advance. Maaaaybe a cam but I'd probably be fine with the stock cam (not sure how much RPM the stock cam is good for though...any idea @KartFab?)My power land 420cc Dragbike went 60mph at 300’. It was limited with the stock flywheel not enough timing.
it only had a NR racing 306 cam , 34mm eBay koso carb , exhaust , and the 40 series plated kit from gopowersports. And a flywheel timing key. And a long rod (piston top lip shaved off by hand to clear !)
so eliminate the governor in that case since i'm cracking it open for a rod and cam?You should get a billet rod, advance timing by 4 degrees, and get an NR racing 280 cam, torque grind.
In that case I might go with a stock lift cam (since I'm already opening up the engine anyway). NR Racing makes one called the 250 Twister. Sort of like a MOD2 but for a big block. 5,500 - 6,000 RPM would be all I would need since if I ran a big block I'd probably run 22" ATV tires. 6:1 maybe 6.2:1 gear ratio. That would be killer.If I remove governor, then I’m putting a cam in it. Stage 1 adds like 10-25% more hp, and a cam adds a crap ton more.
Definitely ditch the governor if you're going through the trouble of putting a rod in it. Also get a billet flywheel if you're running anything other than a GX390. The genuine Honda flywheels are supposedly built pretty good, but the clone ones are a bit weaker.so eliminate the governor in that case since i'm cracking it open for a rod and cam?
Definitely ditch the governor if you're going through the trouble of putting a rod in it. Also get a billet flywheel if you're running anything other than a GX390. The genuine Honda flywheels are supposedly built pretty good, but the clone ones are a bit weaker.
No. I never made it that far cause it kept melting the internals on the 44c magnum driver. But the belt never had issues.Did you have problems shredding belts? If I was going to build a big block it would probably just be Stage 1 with billet flywheel/rod, thin head gasket and a timing advance. Maaaaybe a cam but I'd probably be fine with the stock cam (not sure how much RPM the stock cam is good for though...any idea @KartFab?)
Would you say the regular 40 series driver is better than the 44c driver then? Or did you only ever run that 44c? I'd probably pick up a Comet 40 kit from OMB Warehouse rather than GoPowerSports. They're cheaper there (probably because the backplate they use is a lot less sturdy). $220 vs $370.No. I never made it that far cause it kept melting the internals on the 44c magnum driver. But the belt never had issues.
I was always build my stuff for heads up drag racing stuff. Might have a little effect on it also. Not a lot of actual off-road areas for karts in my area.