I don't want to blow up my Predator 212 with the governor removed

[sf_karting]

Hey guys. Previously, I made a post where I tried to get help on identifying my go kart frame. I found out it is a MxK Racing Demon II from the mid 1990's. In that thread, I also was asked questions about the predator 212 that came with it that has the governor removed. The whole governor unit was removed and the hole was plugged with a screw. Now that the engine can rev much higher, what should I do to prevent the valves from either going through the piston or to prevent them from mushrooming? As of now, I'm thinking of replacing the valves and pushrods with stronger billet parts, and I'm most likely going to buy heavier valve springs. Any other recommendations as what I could and/or should do to prevent a potentially bad end for a good, nearly brand new engine?

 

[Tpdingo]

If you don't rev the motor at full RPM for minutes on end, you'll be fine. Also don't replace any parts if you want the motor to let it last.(the valve springs will "govern" the engine to 5500rpm due to valve float, nothing to worry about).

Now if you want more power, the first things are a billet rod and billet flywheel. Without these upgrades any other mods you do will result in a broken block and or giant chunks of metal getting thrown out and possibly injuring you. Once these upgrades are complete, you are free to change anything. Want more flow, get a better cam. Want more RPM, get heavier valve springs. Want more bang, get a bigger jet or better a bigger carburetor. These engine have loads of mods but the essential two are billet rod and billet flywheel.

 

[sf_karting]

I will look into those mods. Thank you for the suggestions, I appreciate it.

 

[Kartorbust]

If you don't rev the motor at full RPM for minutes on end, you'll be fine. Also don't replace any parts if you want the motor to let it last.(the valve springs will "govern" the engine to 5500rpm due to valve float, nothing to worry about).

Now if you want more power, the first things are a billet rod and billet flywheel. Without these upgrades any other mods you do will result in a broken block and or giant chunks of metal getting thrown out and possibly injuring you. Once these upgrades are complete, you are free to change anything. Want more flow, get a better cam. Want more RPM, get heavier valve springs. Want more bang, get a bigger jet or better a bigger carburetor. These engine have loads of mods but the essential two are billet rod and billet flywheel.

Saw an engine that they kept the stock springs in and the valves floated and they ended up with piston kiss in the valve and bent the valve stem.

 

[Tpdingo]

Saw an engine that they kept the stock springs in and the valves floated and they ended up with piston kiss in the valve and bent the valve stem.

I said don't rev it for minutes on end. When you blow a valve, then u have an excuse to rip apart an entire motor and build it up!

 

[Kartorbust]

I said don't rev it for minutes on end. When you blow a valve, then u have an excuse to rip apart an entire motor and build it up!

It doesn't have to be for minutes at s time, could be a quick throttle surge that does her in. Rare, but could happen.

 

[bob58o]

Hemi's and old non-hemi's have simple valve spring retainers that can slip off the valve quite easily. I'd be more confident with the retainers/ split-keepers that come on the newer non-hemis. Also if you upgrade the valves on the hemi (or old non-hemi) to SS, those require the same type of automotive style retainers with split-keepers that come on the new non-hemis. I have no data to support my claim that you are less likely to drop a valve with the automotive style retainers/keepers.

 

[ezcome-ezgo]

I have no data to support my claim that you should take Bob's advice.

 

[sf_karting]

Hemi's and old non-hemi's have simple valve spring retainers that can slip off the valve quite easily. I'd be more confident with the retainers/ split-keepers that come on the newer non-hemis. Also if you upgrade the valves on the hemi (or old non-hemi) to SS, those require the same type of automotive style retainers with split-keepers that come on the new non-hemis. I have no data to support my claim that you are less likely to drop a valve with the automotive style retainers/keepers.

Well I have one of the newer Non-Hemis. It has part number 69730 and it was manufactured sometime in 2018. I'm not sure what the major changes are from generation to generation but all I really know is this engine is very new and the governor has been removed.

 

[bob58o]

I'm not sure what the major changes are from generation to generation but all I really know is this engine is very new and the governor has been removed.

Generation I
69730
Wedge Style Combustion Chamber
25mm / 24mm Valves
5.5mm Valve Stems
Slip-On Valve Spring Retainers (Don't know what they are called)
Stud Mounted Rocker Arms
Dished Piston

Generation II
60363
Hemi Style Combustion Chamber (Canted Valves)
27mm / 25mm Valves
5.5mm Valve Stems
Slip-On Retainers
Shaft Mounted Rocker Arms
Flat-Top Piston

Generation III
69730 (same SKU# as Gen I)
Wedge Style Combustion Chamber
27mm / 25mm Valves
5.0mm Valve Stems
Automotive Style Retainers with Split Keepers
Stud Mounted Rocker Arms
Dished Piston

 

[WrenchnIsWhatIdo]

look on the linkage on the top of the carb they have a stop screw for wide open throttle just screw it down so you get less WOT

 

[65ShelbyClone]

As of now, I'm thinking of replacing the valves and pushrods with stronger billet parts, and I'm most likely going to buy heavier valve springs. Any other recommendations as what I could and/or should do to prevent a potentially bad end for a good, nearly brand new engine?

Stronger valvetrain will just move the weak link to your connecting rod and flywheel. If a valve drops, the engine might be rebuildable. If the flywheel or rod goes, it will take the engine with it. You would be money ahead leaving the bouncy parts alone and upgrading the spinny parts instead.