Gain 2hp more on your 14/16 and 18/20HP Vanguard V-Twin!

Don't quote me on the 2HP, but Ive noticed the factory restrictors in the exhaust port on my 20HP aswell, probably to gain the *Clean on the EPA rules.

Will this make mine a 22HP   

Anywho: Quote from: *6x6world.com*
http://www.6x6world.com/forums/engines/26083-briggs-vanguard-14-16hp-18-20hp-engine-upgrades-identification.html

Briggs Vanguard 14/16HP & 18/20HP Engine Upgrades and Identification

   OK everyone, I'm going to try and help anyone out that might be wondering about upgrading or identifying the 14HP/16HP or 18/20HP Briggs Vanguard they have. This has been discussed before, but I'm going to lay out all the details for everyone.

   First off, if you have a 14HP Briggs Vanguard in your Max or Argo and want 2HP more, inexpensively and easily, this is for you. This is also a good way to tell if you have a 14HP or 16HP Vanguard (I know, it usually says the HP on the air cleaner decal or you can trace it by the engine ID tag). The 14HP and 16HP are both 480cc engines and are pretty much the same with 2 minor differences. First, the 16HP has a slightly larger carburetor venturi. Pick up a 16HP carburetor (off ebay or Craigslist) for your 14HP Vanguard and bolt it right on.

Next, remove the exhaust manifold and look in the exhaust ports. If you see one of these little power robbing b@stards in each of the ports, then you have a 14HP engine. All you have to do is simply remove these pieces of junk with some pliers and you're set.

Now with the new carb and no restriction in the exhaust, you have a 16HP engine.

   The same goes for the 18HP and 20HP Vanguards. They share the same displacement as each other, 570cc. The 18HP Vanguards have those darn exhaust restrictors in the exhaust ports of the heads and a smaller single barrel carb. The 20HP Vanguards don't have the restrictor rings and they have a 2 barrel carb, but you'll have to get the carb, intake manifold, carb spacer, and tin air cleaner bottom if you want to upgrade your 18HP to a 20HP engine.

   Here's a picture of one of those power robbing restrictor rings found on the 14HP and 18HP Vanguards. After you remove them you'll want to turn the plastic tab on the carb for the fuel mixture to richen it up so you compensate for the freer flowing exhaust you now have.

I'm glad you brought that up. When I did the custom exhaust on MULE 2's 18hp vanny a few weeks ago, I found and removed those things. I really wasn't sure what the point of them was, honestly. I DID know about the 2bbl carb on the 20hp version, didn't know about those rings. All I knew, is they looked like I really had to get rid of them...

Doc Sprocket wrote:

I'm glad you brought that up. When I did the custom exhaust on MULE 2's 18hp vanny a few weeks ago, I found and removed those things. I really wasn't sure what the point of them was, honestly. I DID know about the 2bbl carb on the 20hp version, didn't know about those rings. All I knew, is they looked like I really had to get rid of them...

Yea! They really make the exhaust port smaller in dia. - I thought they were there for some sort of a heat shield, lol
- I'll try to get a good picture of those before and after removal also.

Yeah- I really should have documented that. Instead, I kinda looked at them like ...WTF?... Yanked them out, threw them in the scrap bin. I didn't know what they were SUPPOSED to be for, but they looked like a restriction to me...

I pulled the rings out of my 16hp vanguard. I do notice the better flowing exhaust on it. plus I adjusted the fuel mix screw to 2 1/2 whole turns. and adjusted the link from the gov arm to the carb. much better now with the few extra rpm's thrown in, I pesonally think its got more power since I did that.