My kart build log progression.

[ModdedMotor212]

i like how this place is a ghost town so i will rarely get interrupted during my build log.
So it starts like this,bought off craigslist.

Those wheels are irrelevant to fitment of the kart. It was just a deal bonus. Anyways...

I bought Harbor Freight wheels for the front which are basically soldered at the hub and that where it broke SO i welded the hub on. It isn't pretty but works flawlessy.

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Also bought a tire..1wheel drive as of now..AGGRESSIVE tread..


Not the greatest picture but..

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Needed more power! so i removed the governor,put in 18pound valve springs, and a forged aluminum connecting rod, 6:1 gearing and tore into the dirt like THIS:

mind you that was with one wheel drive with and aggressive tire tread at around 5200+/-RPM.
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I was told gearing higher decreases torque so i wouldn't spin the tires so easily so i did a 4.8:1 ratio:

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4.8:1 gear ratio with a clutch did this up a small incline:

Yet still had more than enough power to dig a hole quickly. one wheel drive and really light weight kart.

[ModdedMotor212]

So i bought a torque converter so i could cruise at slower speeds without burning up the clutch and could potentially gear higher all while gaining torque. win/win. gaining speed and gaining torque.:

BUT!!
the torque converter wouldnt clear the tire
SO!!
i lengthened the frame. another bonus of frame lengthening is when i gain even MORE power from engine mods should be easier control at speed and less chance of wheelies,even though it'd look cool.

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and since i wanted to add a bit more speed...12tooth TAV sprocket:

4:1 gear ratio.
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Thought it would lessen the torque but didnt make a difference. Stock camshaft too Not the best spot to peelout with a light layer of dirt but:

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As if that wasn't bad enough i bought a camshaft for torque. .290lift @104LSA 246duration.not enough to affect torque.

Also got 26 pound springs for it and WOW i can say the beast has been un leashed.
Also bought new TAV springs..:

Orange driver for 1500 engagement and yellow driven for later upshifts or in my case less wheel spin.

[ModdedMotor212]

Getting ready for 2 wheel drive : (chassis mod)


i do not recommend ebay bearings. Highly recommended to get them elsewhere:

[EVILWS6]

Looks like it's coming along nicely.

[ModdedMotor212]

GX390 carb. huge difference. Fits perfectly and matches the intake and exhaust ports. Here's a comparison between stock and 390 carb:

i also jetted the main and pilot jets.
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Flame Snapshot:

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i also purchased a 36 tooth axle sprocket to try out. im going to try out the live axle with either 6:1 or 4:1 ratio first to see how much of a drag these ebay bearings have but:

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[ModdedMotor212]

36 tooth and live axle with gx390 carb. ( 3:1 gearing )



With this gear ratio i haven't lost ANY torque with my engine mods. In fact i still have some to gain. Live axle helps a TON with acceleration.

[ModdedMotor212]

short 3:1 gear ratio test.
i've been told the belt wouldn't hold up.
been told the kart would never move an inch.
But nobody who claims that theory can back it up.
So here's to prove it works..My main jet is too big in this video. i'll have a smaller jet within a week.
https://youtu.be/_HQxVSHeRVg

[SYCARMS]

The added engine power from the cam and carboration makes it possible.

[ModdedMotor212]

Originally Posted by SYCARMS

The added engine power from the cam and carboration makes it possible.

Kind of right. Actually it is the yellow driven spring that makes it possible.

I just tried it with the stock red spring on hole #2 and it didn't move anywhere. I wish there was a stiffer spring than yellow.
i thought i stretched the belt so i put the yellow spring back on and on hole#2 to make sure and now it works again. Will be putting it on hole #3.

[ModdedMotor212]

Well i was going to put the TAV yellow sring on hole #3 but i know i need a later upshift than that so i put it on hole #4.
"Hole #4?? It doesn't have 4 holes." haha.. well it does now.


If you have a modded motor with a T/C .. you haven't felt acceleration yet until you've been on hole #4.
I am now a bit curious about hole #5. It may possibly be overkill.

[ModdedMotor212]

Has anyone figured out i'm crazy yet?
If not...hahahahaa:



I need a stiffer spring than yellow.
I am curious about hole #6 but it would take at LEAST 2 people to make that happen. i Had to use my man strength and stand on the driver to make #5 happen.
Was just an experiment.

-Also forgot to add i did a 6degree ignition timing advance.

[ModdedMotor212]

One carburetor bowl lasts about .2tenths a mile.
Found that out by accident by leaving the fuel valve off.

[ModdedMotor212]

Also got a fuel pump for high speed, long road travel.

[ModdedMotor212]

4:1 gear ratio speed-run.
https://www.youtube.com/my_videos_an...?v=EeyJHhoanIQ
Aprox. 3800 RPM was achieved. STRANGE how TAV maxes out and i can only go 42 mph with a 4:1 gear ratio.

i will be putting on the 36tooth axle sprocket for a 3:1 gear ratio and recording a new top speed run just fr comparisons sake.

[ModdedMotor212]

Broke my first belt:



3:1 gearing with a TAV like this is absolutely pointless.
I made it to 44.5mph which is 2mph over the 4:1 gearing. Don't do 3:1.

I will be gearing down now to at least 5:1, maybe 6:1. i think 4.8:1 is the absolute highest gear allowed.

It wasn't the torque that killed it...it was the horsepower. The "high" speed.
a bigger driver, driven, and belt i assume would have better all-around performance allowing for more speed. You know, like a snowmobile has.

[ModdedMotor212]

Kevlar belt.
Time to re-gear.

[ModdedMotor212]

I have another gx390 carburetor .
i'm thinking about modifying it for an alcohol/methanol blend.
And tuning the high-speed needle a bit rich so i can run a dry shot of nitrous at WOT.

Along with a silver/blue driver spring combination for an engagement of 3600rpm with driven unit on hole #4 and a 6:1 gear ratio for a very STRONG acceleration.

The pick-up should be intense.
I imagine thick tire marks on the ground thus needing wider tires for traction.

Funds are limited, not sure which one to get first.
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about 50% ethanol and 50%methanol. Don't worry. I know all about flushing the system with gasoline after each use. Don't want any internal corrosion.

[ModdedMotor212]

The Torque Converter is nothing but a speed limiter so i put the clutch back on.
Had to modify the frame and chain

I will post a video of the speed run with speedometer overlay. It will just be a laggy video but with real speed results and that's all that really matters. Going for 60mph.

Gear ratio: 4.8:1
And this kart will pull the ratio too.

[[non ethanol/methanol tune]] well..just a little.Like 20%]]

[ModdedMotor212]

4.8:1 clutch speed test. I was running terribly rich. found out my carburetor float was stuck open due to debris. BUT THIS KART STILL PULLED IT! haha



https://www.youtube.com/watch?v=FZWPvAyQehk

Alky tune is next.

[ModdedMotor212]

I can't believe I left out the ARC Billet rod in my first post , 26 pound springs, and removed governor:
Will be getting stronger springs.

Experimental camshaft:
EDIT/ADDED:

Cam specs .380 lift ( .022" away from coil bind with 26pound springs).
120psi compression . Got noticeably harder to pull on the compression stroke.

Had to grind off multiple areas of the crankshaft and the block for this cam to fit.
Now I need to relieve the crank-case pressure so I don't burn oil due to the high compression.
Also need to port the exhaust. More than sure the intake would benefit as well. and chromoly pushrods. The high lift already bent the stock pushrod on the intake side.

[ModdedMotor212]

Ported the exhaust cause it was necessary :


Checking out the exhaust flow :

https://www.youtube.com/watch?v=_Y1UI0PSu4k

Got ahold of an engraver:

[ModdedMotor212]

The image hosting website I was using went over their monthly data usage by 1.8 PETAbytes and currently owe over 12thousand USD because of it. Will they be able to pay it off and keep my pictures up? i dont know.{postimage.org }

Anyways:
Ported the intake with a tumble-polish VERY nicely although i missed a spot in porting the flow goes STRAIGHT in there:

[IMG][/IMG]

Also bought chromoly pushrods,reset my valve lash on compression stroke of course, found out my intake PR was longer than the exhausts, idk how, and i gained compression due to less valve overlap. Now at 140psi compression. still at 8.5 compression ratio though.

[ModdedMotor212]

New Channel. I suggest checking it out: https://www.youtube.com/channel/UCz5...qU8EgaNPaf55cg

2nd video of the channel: Checking out The turbo.
Subscribe, Like, and DEFINITELY share cause it will get good.

Now I need to go back and take off some ignition timing and need high octane fuel. perhaps really high octane. But I haven't tested my N/A engine yet! I can't wait.

Expect drifting videos. And not those WEAK powersliding videos people call "drifting" either. Burnouts, peelouts, and who knows what else. Green flame maybe? I know how to do it!! I don't know how well it'd show from the exhaust but it can be done.

[ModdedMotor212]

Bent stainless steel push rod....(pic1)

So I got Chromolys....(pic2)
The only way those will even possibly bend is if i have piston-to-valve contact.

[ModdedMotor212]

Just playin' around lol. Not hooked up yet but yehh..

[ModdedMotor212]

.380 camshaft idle and rev test:
Look at those wide flames and the distance they shoot!! haha.
Naturally Aspirated...for now.

https://www.youtube.com/watch?v=jmAP...utu.be&t=5m49s

[ModdedMotor212]

36 poundvalve springs. Allows 8100+ RPM

[ModdedMotor212]

Turbo Kit:


Will upgrade it in the future.

[OLDKID]

It's obvious , you are a Madman !
Leave the engine alone for a day .....and PUT A SEAT IN IT !!!!

[ModdedMotor212]

Originally Posted by OLDKID

It's obvious , you are a Madman !
Leave the engine alone for a day .....and PUT A SEAT IN IT !!!!

Yes. I Really ... Really need one.

Y'know Christmas is coming and..hehe.. i could use a racing seat

[ModdedMotor212]

Turbo Flames #1


Turbo Flames #2

[ModdedMotor212]

WIDENING PT 1.

Originally Posted by OLDKID

It's obvious , you are a Madman !
Leave the engine alone for a day .....and PUT A SEAT IN IT !!!!

Working on it.
Just widened the right side for stretching/passenger room.

[ModdedMotor212]

Widening continued: Passenger side. \\\

[ModdedMotor212]

New powertrain !
724cc engine with hydrostatic limited slip differential transmission.



Widening the kart into a kar of some sorts as well with headlights and interior gauges and other stuff.

[SYCARMS]

Looking good.

[ModdedMotor212]

Originally Posted by SYCARMS

Looking good.

Thanks, I have a good amount to do.
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If anyone wants to subscribe, feel free to leave a comment.
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Widened and reinforced middle. Still need to move steering over.


9inches narrower than a Chevy Sonic:

[ModdedMotor212]

Transmission Mounted:



Now need to lengthen the axle and think about engine mounts and height.

[ModdedMotor212]

Got the motor mount 100% fabricated and the sides as well.

Moving the steering ASAP.

[SYCARMS]

Your getting closer, looking good.

[ModdedMotor212]

bigger 212cc Jet


I'm using the 212cc engine on the riding mower. Will definitely be quicker and faster.

[ModdedMotor212]

back to the 212cc..
My .380 camshaft caused so much compression thus causing blowby that i had to file the piston rings to eliminate it.
I noticed a semi "flat spot " past half throttle during throttle tests and either need a bigger main jet or emulsion tube, or maybe both.
but here are the flames:

[ModdedMotor212]

Been a while since i posted but here is a bit of an old-to-me pic of the mower i modified and put the 212 engine on.
It now needs dual valve springs to handle the radical camshaft.

[ModdedMotor212]

Well the unfortunate end has come to my project.

I believe my billet rod has come apart after miles of riding.
I took off the cylinder head and while rotating the crankshaft the piston doesnt even move. The crankshaft moves half a rotating and clinks against the rod.

I do not own an inch-pound torque wrench so if anything i overtorqued the chromoly rod bolts but should definitely not come undone like that.

I'll see after i pry off the sidecover.

[ModdedMotor212]

Rod unscrewed itself.
So much power to bend a chromoly bolt(which gets heat treated at over 40,000+ psi in the making) .
Punched the oil dipper straight through the block. Irreparable rod.


You can see the aluminum shards in the oil. I know the oil looks pretty dark. Didn't take long for this high compression oil to darken.

[ModdedMotor212]

Oh well i guess.
It was cool while it lasted.

[SYCARMS]

Are the rod bolts torqued to inch pounds and not foot pounds? Never heard of torquing a rod to inch pounds.

[ModdedMotor212]

Originally Posted by SYCARMS

Are the rod bolts torqued to inch pounds and not foot pounds? Never heard of torquing a rod to inch pounds.

170 inch pounds : http://www.arcracing.com/6254-arc-bi...2cc-3-308-std/

Equivalent to 14.2 ft lbs.

[SYCARMS]

I'm thinking the engines vibration worked the bolts loose. I know people who build the Briggs & Stratton or Honda engines for Jr. Dragster or those race karts and they always have the crank shaft balanced. Also what RPM are you peaking at? Those engines stock are only designed for about 2000 rpm max. One of my customers son races Jr. Dragster. He started with a 5HP Briggs & Stratton. His redline I believe he told me is 5500 rpm. He has over $3000.00 in that engine and keeps a complete spare engine. He told me the only thing stock in the engine is the case. That really sucks that it come apart so quickly.I would talk to someone who builds this type of engine for as to why it come apart.

[ModdedMotor212]

The last video i will make with this engine most likely.
43mph top speed. average 32.

[SYCARMS]

No video

[ModdedMotor212]

There we go. I hadnt posted in so long i forgot how to instill videos.

Now the reason i havent updated more is because the chain flew off AND THEN days after, the connecting rod bearings spun which caused the lower part of the billet ARC rod to back out and put a hole through the block.

All i really need is the $20 bearings i think. The bolt threads are still in good shape.

I really could've had a better and faster video but the circumstances werent great so 43mph is as fast i could get. which is why its been 9months since posting. I've been 58mph with this motor and that was with a .290 cam. This is a .380cam in an untuned motor. i have a new-to-me car/toy to play with now

[neo71665]

The guys I know that run those hoped up predators safety wire the rod bolts. Those things are bad about their vibrations and shaking anything loose not tied down.

Might want to look into buying the jig to drill the bolts and nuts then learn how to do it.

[Shadowfocus603]

I just lost a motor to the rod bolts backing out myself. Stock rod in my case. It didn't punch the case but the rod and crank were toast as well as the piston. I could probably hone the bore to save the block but it's not worth it to me.