212 Predator performance kits from BMI Karts

[jferguson]

Curious how much difference the performance kits from BMI make. Not interested in pulling the engine apart at this point, just spice it up for my 9 year old. Does almost 30 mph stock but he wants more. They have stage 1, stage 2, etc. Let me know what y’all think.
Thanks!

 

[panchothedog]

Doesn't matter which supplier you buy the parts from. Pretty much all the same. Stage one header pipe, free flowing air filter and carb jet will get you a increase of 25% to 30% if you delete the governor. If not the kart won't feel much different. Are you running a centrifugal clutch or a torque converter?
Without the governor the engine can over rev and self destruct. On rare occasions this can be dangerous. Much easier to over rev with the centrifugal clutch. The torque converter when it shifts into the higher range the extra load on the motor prevents it from over reving. Rear tire size plays a role as well.
Tell is a little more about the vehicle.

 

[panchothedog]

I see from another post it's got 6" wheels . DON'T DO THAT. Keep all your questions on one thread. It keeps us from wasting time. So it's 30 years old. Nothing wrong with that, but I bet it's got a centrifugal clutch and not a torque converter. Clutch and small 6" wheels are a prime candidate for over raving the engine if you delete the governor.

 

[jferguson]

I see from another post it's got 6" wheels . DON'T DO THAT. Keep all your questions on one thread. It keeps us from wasting time. So it's 30 years old. Nothing wrong with that, but I bet it's got a centrifugal clutch and not a torque converter. Clutch and small 6" wheels are a prime candidate for over raving the engine if you delete the governor.

15” tires. Centrifugal 10T clutch w/ 420 chain. 6:1 gear ratio. If I deleted the governor, I would get the billet flywheel and upgraded rod. Would that alleviate the over-revving concern?

As far as creating a new thread to address a new part of the kart, I thought that’s what the sub categories were for…

 

[panchothedog]

Didn't mean to bark so hard about multiple threads. Billet flywheel and rod are exactly what you do so the engine can rev from here to eternity safely and stay in one piece. Obviously that requires opening up the engine so if you go that route that is the time to install a bigger cam and stiffer valve springs. Might have been a little over zealous about the over raving issue. It would require a long uninterrupted straight holding the throttle wide open for a while and even then you would probably float the valves which in turn would limit RPM. I would
assume at 9 years old he is driving the kart under your watchful eye. As long as you keep him in a situation where he can't hold it wide open for 1&1/2 or 2 blocks you can probably delete the governor with the stage one. Fantastic that at 9 he already is wanting more from the kart. With the open header pipe exhaust be sure to get a performance muffler. If you don't your neighbors will hate you and your ears will be ringing. They are not only loud, but quite sharp.

 

[jferguson]

Didn't mean to bark so hard about multiple threads. Billet flywheel and rod are exactly what you do so the engine can rev from here to eternity safely and stay in one piece. Obviously that requires opening up the engine so if you go that route that is the time to install a bigger cam and stiffer valve springs. Might have been a little over zealous about the over raving issue. It would require a long uninterrupted straight holding the throttle wide open for a while and even then you would probably float the valves which in turn would limit RPM. I would

assume at 9 years old he is driving the kart under your watchful eye. As long as you keep him in a situation where he can't hold it wide open for 1&1/2 or 2 blocks you can probably delete the governor with the stage one. Fantastic that at 9 he already is wanting more from the kart. With the open header pipe exhaust be sure to get a performance muffler. If you don't your neighbors will hate you and your ears will be ringing. They are not only loud, but quite sharp.

Thank you so much. That’s exactly the info I needed! He’s a wild man for sure!

 

[panchothedog]

If you go into the engine, the videos produced by Red Beards Garage are some of the most helpful and detailed on engine building out there. The ones where he is by himself building the engines on the bench tell you everything you need to know to confidently tear into one successfully.

 

[jferguson]

If you go into the engine, the videos produced by Red Beards Garage are some of the most helpful and detailed on engine building out there. The ones where he is by himself building the engines on the bench tell you everything you need to know to confidently tear into one successfully.

This is what I’m going to do initially. Should be all he needs for a while.

$50
https://www.bmikarts.com/Hilliard-Extreme-Duty-34-Clutch-10T-4041-_p_728.html

$220
https://www.ombwarehouse.com/predator-212-non-hemi-governor-removal-kit.html

$8
https://www.ombwarehouse.com/ar3910x-racing-spark-plug.html

 

[panchothedog]

Are you still running the stock air cleaner and exhaust. Eliminating them and adding the bigger carburetor jet is where the power upgrade is. According to a post by Go Power Sports a 212 predator with govoner delete and stiffer valve springs they claim a little over 10 HP. They post a dyno sheet to back it up. That will put a ear to ear smile on your sons face. So glad to see you are going with the rod and flywheel. That will allow you to do ANY modifications you want in the future.

 

[panchothedog]

Do you know if your engine is a hemi or a non hemi? Flywheel and cam are
NOT interchangeable between the two.

 

[jferguson]

Do you know if your engine is a hemi or a non hemi? Flywheel and cam are
NOT interchangeable between the two.

Non-hemi. Buying a stage 2 kit, gasket set, better plug, and upgraded clutch, all from OMB. Will get fresh Mobil 1 when it's back together. Go Power Sports was very helpful on the phone and let me know the 18 lb springs would make the governor removal safe. I am going to hold off on the rod and flywheel for now. This very well may be all he needs. Don't know that I will put hundreds more into this little Harbor Freight motor.

 

[redflash]

coulda, shoulda, woulda......bought a 420 when on sale and start with 13 hp. with moderate ( cam springs, rockers, carb) work cn end up with 15-18 horses. Instead of 212 with $$$$ mods

Da Redflash

 

[jferguson]

coulda, shoulda, woulda......bought a 420 when on sale and start with 13 hp. with moderate ( cam springs, rockers, carb) work cn end up with 15-18 horses. Instead of 212 with $$$$ mods

Da Redflash

Not a Ghost 212 for more than $100 less?

 

[redflash]

It will turn a higher rpm, but the 420 has so much more torques for pulling us fat guys up steep inclines. Ghost has problems..you still have to mod.
no gas tank, no throttle plate, and they are not very proven as of yet ....I believe ! ask the other guys

 

[jferguson]

It will turn a higher rpm, but the 420 has so much more torques for pulling us fat guys up steep inclines. Ghost has problems..you still have to mod.
no gas tank, no throttle plate, and they are not very proven as of yet ....I believe ! ask the other guys

That’s helpful. Thank you.

 

[madprofessor]

Will get fresh Mobil 1 when it's back together.

Any 30-weight oil would be fine, but for me, I only use $11 per quart Royal Purple Break-in Oil, even for oil changes. Only takes 1/2 quart.

Go Power Sports was very helpful on the phone and let me know the 18 lb springs would make the governor removal safe.

That makes me really upset. Maybe they were thinking you were going to have a billet flywheel............ 18# springs ungoverned can spin up a 212's rpm plenty enough to explode an OEM cast iron flywheel. Deleted governor = billet...........both rod and flywheel.

coulda, shoulda, woulda......bought a 420 when on sale and start with 13 hp.

I went 15 hp. modded up 212cc myself, and regret it...........because all that power is only in the higher rpm range. Consider building 2 karts like I am now. Moving the hotrod 212cc from its 520# kart to a bare minimum kart I'll build, very light weight. Putting a 420cc in its place.

 

[jferguson]

Any 30-weight oil would be fine, but for me, I only use $11 per quart Royal Purple Break-in Oil, even for oil changes. Only takes 1/2 quart.

That makes me really upset. Maybe they were thinking you were going to have a billet flywheel............ 18# springs ungoverned can spin up a 212's rpm plenty enough to explode an OEM cast iron flywheel. Deleted governor = billet...........both rod and flywheel.

I went 15 hp. modded up 212cc myself, and regret it...........because all that power is only in the higher rpm range. Consider building 2 karts like I am now. Moving the hotrod 212cc from its 520# kart to a bare minimum kart I'll build, very light weight. Putting a 420cc in its place.

So many options. You’re saying you regret modding up the 212? Are you saying you’d do the 420 instead? This is going to be ridden in a neighborhood and again he’s 9, so 13 is more than I want to put on there. Any idea ballpark hp on the 212 if I remove governor, add springs/billet rod/flywheel, header, upgraded air filter, and upgraded carb/jet? What about the Predator 301/8 hp for moderate gains?

 

[madprofessor]

You’re saying you regret modding up the 212?

I should be more specific.............No regrets for doing the fun job of hotrodding the 212cc, and only a little regret for doing things in the wrong order. Never considered how heavy my "one size satisfies all" concept for a one-of-a-kind kart build (SchizoBallz) would turn out, should have just gone 420cc in the first place. The jacked up 212 can never deliver the low end torque needed to really make it a fun ride offroad, and it ain't never gonna be street legal.
In the end there's no lasting regrets, had planned to do the bare skeleton kart build (BareBallz) afterwards all along. When that kart gets the 15+ hp. 212cc transplanted to it, it's going to be a deliriously fun ride that should do wheelies and doughnuts all day long. SchizoBallz will get the 420cc torque it needs to scare everybody, that's what the passenger side motor-killing panic slapswitch is for. I was ecstatic how the 12 hp. (212cc) DragginBallz minibike turned out, just too terrifying to properly test-ride it. Poor guy in Ohio that bought it is probably still in the hospital. Current and near-future builds will undoubtedly be just as satisfying once everything is shuffled into place.

 

[jferguson]

I should be more specific.............No regrets for doing the fun job of hotrodding the 212cc, and only a little regret for doing things in the wrong order. Never considered how heavy my "one size satisfies all" concept for a one-of-a-kind kart build (SchizoBallz) would turn out, should have just gone 420cc in the first place. The jacked up 212 can never deliver the low end torque needed to really make it a fun ride offroad, and it ain't never gonna be street legal.
In the end there's no lasting regrets, had planned to do the bare skeleton kart build (BareBallz) afterwards all along. When that kart gets the 15+ hp. 212cc transplanted to it, it's going to be a deliriously fun ride that should do wheelies and doughnuts all day long. SchizoBallz will get the 420cc torque it needs to scare everybody, that's what the passenger side motor-killing panic slapswitch is for. I was ecstatic how the 12 hp. (212cc) DragginBallz minibike turned out, just too terrifying to properly test-ride it. Poor guy in Ohio that bought it is probably still in the hospital. Current and near-future builds will undoubtedly be just as satisfying once everything is shuffled into place.

Wow. Sounds like a garage full of cool machines. Are you able to help give me an idea of the approximate hp for the 212 after the mods i mentioned? Any comment on the 301cc/8 hp predator?

 

[madprofessor]

If you maximize compression by choosing your billet rod to be .020" over-length with a flattop piston, and using a .010"-.012" head gasket, use a billet flywheel with rare-earth magnets and higher spark advance coupled with an advance key to reach about 36-degrees spark advance, use a hi-perf coil (resistors disabled to prevent spark retard at high rpm), use a .265 intermediate cam, add a pulse fuel pump, use the right venturi-type intake adapter with a hi-flow air filter, use a header pipe without a weiner muffler, put in .022 low jet and .036 main jet, upgrade to 22# valve springs, delete all of the components inside and out that make up the governor, delete the oil sensor inside, adjust valve lash int/exh to .003", use Royal Purple Break-in Oil from beginning to end, then you'd be approaching 14 hp. Remember, all that power will only come in at the high end of your rpm range, that's why 420cc are great, their torque kicks in at the start line.
Can't guess what the list you gave would make, and I have zero experience with the 301cc or the new Ghost engines.