Predator Mikuni

IcePS

New member
Hey guys, I’m kind of a noob here getting into the karting/mini biking community. I’m am planning to purchase a predator 212 (preferably hemi) and put it on a frame. However I obviously want to take off the shitty air filter and exhaust. I am going to get a straight pipe header, fully remove the governor, and get a clone Mikuni kit off of amazon and install it. But, I have a few questions. First, how do I fill the hole from the governor and the oil sensor if I take that out?

Second, since the clone Mikuni is a higher end carb, will it be too much for the stock cam, valve springs, and flywheel to handle? Or will I need to replace them? (I would prefer not to)

Thanks in advance! -IcePS
 

flattop1

Dawg 89
Fill the holes with pipe plugs or self tapping screws / or bolts .
No need to upgrade the other stuff .
 

Kart43

Member
It takes a lot more than a straight pipe and an Ebay carb to make these engines work. Your route will probably yield less power and reliability.
 

Lykkan

Member
It takes a lot more than a straight pipe and an Ebay carb to make these engines work. Your route will probably yield less power and reliability.
I call BS
Any jetting from stock EPA settings improves power. Open pipe improves air flow a lot. Not sure what you're going on about
You needa tear the engine down and drill and tap the holes inside the crankcase and then put a bolt in there with loctite so they don't wiggle loose. Be aware if you upgrade valve springs, you need to replace crank rod with an upgraded billet one, and flywheel. The stock valve springs are good to about 5200-5500 RPM before you get valve float and the engine won't rev any higher than that. This is where the build can get pretty expensive quick, if you're seeking higher RPM ranges
 
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DynoDon

Moderator
Not everything you say is correct without explanation. Any jetting from stock epa will not improve power. You can jet to much and hurt power. Also replacing valve Springs don't necessarily mean replacing rod. Turning the engine over 7000 means replacing the rod. Other wise, checking the stock rod on an engine that turns under 7 periodically is wise.
 

flattop1

Dawg 89
Ha ha ha , interpretation and assumptions typically end wrong :)
Advertised claims also end with unmet expectations.
Simply drilling a few holes in the muffler from the engine side and air box could possibly improve things .
 

Lykkan

Member
improving any airflow requires in an increase in fuel, or you'll run leaner than the already lean factory settings.
IcePS, your aftermarket carb will definitely help with the increase in RPM range, as the factory carb wasn't designed for higher air flow than what you're seeking. I'm running the cheap mikuni chinese vm22 also, still tuning mine for higher RPM, but I'm getting 7300 RPM on stock cam (but modified ratio rockers)
Your mikuni will be fine for your application after tuning, but you won't be able to exceed 5200~ rpm with your stock valve springs
 

Dover Power

Member
I call BS
Any jetting from stock EPA settings improves power. Open pipe improves air flow a lot. Not sure what you're going on about
You needa tear the engine down and drill and tap the holes inside the crankcase and then put a bolt in there with loctite so they don't wiggle loose. Be aware if you upgrade valve springs, you need to replace crank rod with an upgraded billet one, and flywheel. The stock valve springs are good to about 5200-5500 RPM before you get valve float and the engine won't rev any higher than that. This is where the build can get pretty expensive quick, if you're seeking higher RPM ranges
He said he did not want to do anything more..
 

Dover Power

Member
WE have talked to so many people its not funny after they buy these chinese mikuni kits and install them.. MAYBE 1 in 10 works out without alot of work and aggravation...
 

Lykkan

Member
WE have talked to so many people its not funny after they buy these chinese mikuni kits and install them.. MAYBE 1 in 10 works out without alot of work and aggravation...
the jetting they come with is probably far from correct. I did e85 on my build so I can't speak for what the gas recommendations would be other than what others have said they've used. It took me a long time to tune it correctly but that's the nature of any carb engine
 

Kart43

Member
the jetting they come with is probably far from correct. I did e85 on my build so I can't speak for what the gas recommendations would be other than what others have said they've used. It took me a long time to tune it correctly but that's the nature of any carb engine
Youhave not had your engine on a dyno or under load so why would you say you have it tuned?
 
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