I tried the search function, maybe I'm retarded, as I already feel retarded asking this...

Put a 21hp on my 16hp GO-Devil LT frame, bought a new 9X6 prop, took it out expected more speed better load capacity... got 8mph....Awwwww DAMMMMIT!!

Bought a tiny tach, checked RPMs, was idling at 1740rpms and WOT (out of water) at 3350RPMs. I figured the extra 750-1K RPMs (getting WOT out of water to 4K) would translate to a huge difference in the water.... Here's the problem…

I need to adjust the governor; to allow it to reach the desired 4K WOT out of water.... Apparently I am doing something wrong... I can get the top end RPMs to 4K, but then I increase my idle to roughly 2500 RPMs...or I can get the idle down to 1200 RPMs....then my max WOT RPMs would be 2800ish... I Donut Fix de Gobernator Rite……

What the hell am I doing wrong? It seems to easy…..ergo apparently, I am retarded....

You need a stronger spring, or need to zip tie a couple links in the one you have. You might be able to bend a tab somewhere too. I've not looked at that motor before.

What brand engine?

Its a briggs 21 vanguard v-twin. I put zip tie on 4 loops on the spring and bent a tab ( one that the spring looped in on) forward and am pushing 4320 WOT out of water? is that too high, as to where I will damage the motor?

I wish there was an easy way to explain the WOT governor speed adjustment on the Vanguard engine - pretty much, the zip tie you put in is not required, and may even be harmful to the longevity of your engine - basically there are some tabs to bend that will control your WOT, as well as idle speed

Since I am not at super computer geek, I don't know how to get you the pages of the service manual on these procedures to this post, so my next recommendation would be to go to some online file server (like tradebit.com ... search vanguard twin service manual) and purchase a copy of the Vanguard Twin service manual to "see" what the procedure is... should be able to get an instant download for around $7.50, - if you plan on keeping the engine, the manual is well worth your $ - just make sure you DON'T select the Liquid cooled model