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Old 01-23-2020, 01:20 PM
belviderepredator belviderepredator is offline
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Default Max 212 safe rpm

Hey ya'll, I'm not sure if this question has been answered before, so please forgive me if it has. Me and my brother have 2 predator 212 hemi's on a Carter hot bodies frame and a yerf dog frame. Both engines run great, and haven't had any mods done to them other than disconnecting the low oil sensor and backing out the throttle screw. My first question is this: how much more rpm does that screw typically give over 3600 and how safe is it to run wide open for long periods of time? The yerf dog has a top speed of around 32 on dirt and the Carter has a top speed of about 25-27 but the engine screams. The yd has a torque a verter and the Carter has a centrifugal clutch with a belt and jackshaft. I feel like I can cruise all day at wot on the yd but the 212 just seems to scream on the carter. I don't want to damage the engine, as the Carter is my cousins kart and neither one of us wants to push it too hard because we can't afford to replace engines right now.
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Old 01-23-2020, 01:25 PM
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I believe the throttle limiting screw only limits the maximum travel of the throttle butterfly. The governor still controls the RPM. Do you mean the governor arm screw??

Also, what's your gearing and tire diameter?
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Old 01-23-2020, 02:14 PM
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I believe the max they'll hit with just backing out the throttle screw is 4300 ish, maybe 4500. And at those speeds the only thing you should be concerned with is the plastic governor wheel. Those tend to grenade inside the engine at speeds over 4700 if my memory is right. Though I had a hemi that went a bit crazy and would top out at 4800 with an untouched limiter screw. Nothing blew up, but it did get returned for a non hemi.

But the tire size and sprocket tooth counts would be helpful for figuring out the true rpm of your engine.
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Old 01-27-2020, 12:52 PM
belviderepredator belviderepredator is offline
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Quote:
Originally Posted by JTSpeedDemon View Post
I believe the throttle limiting screw only limits the maximum travel of the throttle butterfly. The governor still controls the RPM. Do you mean the governor arm screw??

Also, what's your gearing and tire diameter?
I meant the little screw that limits travel of the throttle arm. I would like to keep the governor intact if I can. I just wanted to make sure that backing that screw out wouldn't damage anything. i'm not trying to get any more speed, wer'e pretty happy with them as they are.for now,anywaymy brother tipped the yerf dog on its side about 2 days ago, which it could never do before. we only swapped the 212 onto the yerf dog about 2 weeks ago, and I will say it has way more power than the Honda gx160 that we had on it i'll try to get gearing and tire sizes asap.

---------- Post added at 01:49 PM ---------- Previous post was at 01:42 PM ----------

thank ya'll for helping me so far

---------- Post added at 01:52 PM ---------- Previous post was at 01:49 PM ----------

im a big flattie fan too, especially the big old wisconsins. I have a few briggs too.
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Old 01-27-2020, 01:58 PM
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I'm not sure if that screw affects governed RPM, but at the very least you should get a little more "oomph" out of the engine!

I still want to work on an old Wisconsin, but there is an ad on the local CL for an old cast iron 14HP Kohler. That might be interesting, but it would be freaking HEAVY!
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Old 01-27-2020, 07:33 PM
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You can change the spring position on the governor arm to change the set rpm. The more stretched the spring is, and the further out on the governor arm it's attached, the more authority the throttle linkage has over the governor.

In my experience, you can get about 4200-4500 rpm from it. Keeps you out of the valve float range, but also risks popping the governor inside the case while the engine is running.
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