Mikuni carburetor No need to remove the governor!

[DCFIRE]

Hey guys I have a big Thunder go kart. I was looking to upgrade it a little bit. I happened to be shopping around looking at Mikuni carburetors. One of the Company’s I spoke with was GO Karts USA. I asked them about a stage 1 kit. The tech guy gladly explained to me what it all entails. I was shocked when he told me that I would not have to open my engine up, and remove my Governor. He told me the throttle cable completely bypasses the Governor (doesn’t engage it) and goes directly to the carburetor. I asked if the engine will increase to a high rpm, and if the Governor gear or rod will explode inside the engine? He told me nothing will happen to my engine. He went onto say that the company has been doing it for years, with no issues anyway has anyone heard of this? Is this true? I’m not trying to open up my engine if I don’t need to.

 

[J.S.@SMS]

Did he say that it disengages the governor? There is no way to disengage the governor other than pulling it. It's a plastic gear that's spun by another gear on the crank. Both are in a fixed location, so they cannot disengage. when you route the throttle cable directly to the governor arm, it causes the governor to be incapable of limiting the rpm, but it's still in there, spinning like crazy. And when they reach a high enough rpm (4700 and up if I remember right), that little plastic gear flies apart, and the metal weights go with it (they like jamming between the cam gears and screwing them up). And these engines can rev to 5200 rpm before the valves float. So if you like your engine, do it the right way, and remove the governor entirely.

 

[DCFIRE]

He said the Mikuni carburetor bypasses the Governor entirely. He said none of the gear shredding, or weights flying off will happen and that they have been doing it to they’re engines for years.

 

[onionfmr]

Last fall, I bought an old racing go kart that had a 212 clone engine on it. Seller claimed that he put the new clone engine on the kart and it probably had 2 hours of run time on it. I planned on restoring the kart and using a WB 820 engine and removing the clone engine. Regardless, I ran the kart for 1/2 hour before starting the kart disassembly and restoration. 212 clone engine was screwed. At idle, I could hear a noise in the engine. Sounded like a piece of plastic or wood banging around. Governor was still installed in the engine and had been bypassed at the throttle linkage. With the gearing on the kart and the limited running I was doing, the valves never floated. The other day, I had a use for that kart engine. Decided that I would disassemble it and see what was going on. The plastic governor gear, it's plastic pieces and the metal governor washers were sitting in the sump of the engine. Just food for thought.

 

[mckutzy]

That's sounds like an automated message or an agent that clearly doesn't know what will happen to the engine in this case..
If given the chance.. it will explode inside...

 

[DCFIRE]

Hmmm ok. If I do remove the Governor arm and the gear. Do I need to upgrade my valve springs?

 

[anickode]

No, you don't need to.

Unless you also upgrade your flywheel and con rods, you definitely don't want to.

 

[DCFIRE]

No not planning on upgrading the fly wheel. Will removing the Governor hurt the engine?

 

[JTSpeedDemon]

That rep doesn't know what he's talking about. It is NEVER a good idea to bypass the governor! Many people have blown up their engines, so it's just not worth it.
Removing the governor is for the most part, safe. Unless you upgrade the valve springs, the valves will float around 5200 RPM, limiting RPM, and keeping the risk of blowing up your engine to a minimum.
If you install a billet aluminum connecting rod and flywheel though, the engine is almost entirely safe.

 

[anickode]

No not planning on upgrading the fly wheel. Will removing the Governor hurt the engine?

Depends on the engine. Predator 212s are incredibly tolerant of valve float, which will act as something of a passive governor so you don't grenade your flywheel and con rod (~5000 rpms or so).

Tecumseh flatheads on the on the other hand... They don't deal well with valve float.

 

[DCFIRE]

It’s a Tillotson 212cc