Best Eight Bucks

[OneTimeUser]

Best eight bucks I ever spent. I put a 6 degree offset flywheel key on my 212 Tillotson and it really woke the motor up. All the innerds are stock, with a 24mm Nibbi and a garden variety open exhaust with a hot dog.

Maybe it's just wishful thinking, but it sounds a little bit more ferocious and seems to pull a bit harder.

Anyone ever dynoed a before and after with addition of a 6 degree flywheel key?

 

[Hellion]

Anyone ever dynoed a before and after with addition of a 6 degree flywheel key?

Not anyone currently active on the forum, that can personally answer your question, no, I’m not sure. But there’s a lot of engine tech threads on here with all the speed parts including offset keys. The site search is feeble so try site:diygokarts.com “keyword string” into your search engine of choice.

Stock innerds eh? The best way to do upgrades is by riding the engine stock and then gauging improvement by the seat of your pants. You did it right. Way too many noobs tear apart a new engine and do a Stage 1/2/3 kit and can’t tell what they did, IF they can even get the newly modded engine started, that is. Sorry for the rant.

Show us some engine pics. I like to see everything

 

[Whitetrashrocker]

You better get a billet rod.
That should be the first mod.
They have real bearings and not just aluminum on steel. They oil better too.

 

[OneTimeUser]

Thanks for the advice and info gents. I'm going to look into a billet rod. Mine is electric start (love it), so I won't be getting a billet flywheel.

I looked around quite a bit to learn about the exploding flywheel story/myth/legend/fact. I decided not to worry about it.

Even if it grenades, the back of my seat will be a pretty good scatter shield (I might feel differently if it was on a mini bike and I had the home entertainment center only inches away. I looked on Amazon for chain mail underwear but didn't find any.

 

[Hellion]

I thought we decided valve flutter was the failsafe well before the stock rod overs-speeds, suffers oil starvation, smears the con rod bearings and seizes? I don’t know the Tillotson though, thought they were pretty spiffy out of the box.

When that happens (all theoretical), the rod breaks and rod chunks are scattered around the inside sometimes getting in the way of the crank as it quickly spools down, and there’s no way but out as it punches a hole in the block. Far less catastrophic than the mystical exploding flywheel I reckon.

Make sure you get a cheap billet Chinesium con rod.

 

[Whitetrashrocker]

My stock spring rev limiting 301 lost a rod. Its got the air flow, timing, compression, and 110 octane mods.

From what Ive seen, a rod is by far the best thing for any type of longevity.

 

[Hellion]

That’s a rotaderp rod. You got me there. Plus we myth-busted the exploding flywheel so the rod is now the weak link….

 

[OneTimeUser]

If I understand it correctly, the Tillotson is a bit beefier than the Predator and has a couple more horsepower. Misinformation and BS abounds (who'da thunk it?) on the interweb so I'm not really sure I'm properly informed.

I'm tempted to hot rod the thing, but have reservations about aftermarket parts. I'm told it already has stiffer valve springs and a sturdy con rod. It definitely is more powerful than the Predator it replaced.

I'm going to put a thin head gasket on it next to up the compression a bit.

After that I may study up on cams and try to get a bit more power.

Truth is, at 35 mph and six inches off the ground the thing FEELS plenty fast. All this tinkering is just for fun.

 

[panchothedog]

I thought we decided valve flutter was the failsafe well before the stock rod overs-speeds, suffers oil starvation, smears the con rod bearings and seizes? I don’t know the Tillotson though, thought they were pretty spiffy out of the box.

When that happens (all theoretical), the rod breaks and rod chunks are scattered around the inside sometimes getting in the way of the crank as it quickly spools down, and there’s no way but out as it punches a hole in the block. Far less catastrophic than the mystical exploding flywheel I reckon.

Make sure you get a cheap billet Chinesium con rod.

Valve float will limit the maximum rpm that you can achieve. Valve float can ( and eventually will ) leave one of the valves open when it shouldn't be. Like when the piston is approaching TDC. Bad things are going to happen.
OTU. I don't think your stock Tillotson valve springs are any stronger than any others.
Besides, they are by far the cheapest speed ( better said, reliability ) upgrade you can make on your engine. $12 for a set of 22lb. or 26lb. Springs, to insure that your piston won't collide with one of those " Floating " valves. Dirt cheap insurance.

 

[OneTimeUser]

Best as I can tell the Tillotson comes with 26 lb springs and the Predator comes with 10.8 lb springs. Don't bet the ranch on that, there is tons of info about stiffer springs, but not much that I can find about stock springs.

Last time I "upgraded" a Predator I used 18 lb springs.

 

[Edwin Spangler]

I like playing with different keys (I have many that are shaved to clock the flywheel + or -. I like to mix different intakes and exhausts with different variations of timing added.

For the tiniest amount of effort, these keys have a remarkable effect on engine power and where the power band is.

Its funny. The first time I used one of these keys, I was very familiar with how the engine performed, when it topped out, and how long it takes to get there... First ride I got to the "familiar" top speed, expecting it to stop accelerating. It was disappointingly slow while getting to speed but once it did, the thing just kept going. I did one of those things where it pulls your head back and you look like youve never ridden anything.

A good rule to follow is: The more timing you add, the more top end youll have and less low end.

 

[OneTimeUser]

I found this AI answer to the question: What are the differences between Predator 212 Non-Hemi and Tillotson 212 engines?

The Tillotson 212 engine typically offers about 40% higher output and 10-20% more torque compared to the Predator 212 Non-Hemi, making it a stronger performer out of the box. Additionally, the Tillotson is generally more expensive and comes with upgraded components like better valve springs and flywheel.