Okaydokey thanks for telling me about that. Um, I haven't done anything to seal the case. Is there anything I can do without replace gaskets/seals?
Here's what I was thinking. . .
Lightly sand the intake manifold, apply a generous portion of some type of sealant, but the carb back on and tighten it really hard?
Would that help?
Shouldn't I just get the better carb anyways, so that my engine will last longer?
Engine longevity has little to do with your carburetor preference. That will be determined by other factors such as how you ride, oil to fuel ratios, oil quality etc.
The carburetor will have no bearing on how long your engine might last.
As for your 'fix', yes, your method will work just fine. I doubt that the crankcase gaskets are the culprits here. I'm confident that if you get the intake circuit sealed properly you'll be happier with your current carb.
There are tuning changes you can make such as altering main jet size that will give you better performance. Seal things up and do some test riding. Let us know how things go.
One thing we haven't asked is how many miles/gallons of fuel does the engine have on it? If less two hundred miles don't expect the engine to produce maximum performance. They are slow to break in and need time/miles. 300 is even better.
Also what fuel to oil ratio are you using. If the kit recommended 16:1, drop that to at least 24:1. 16:1 is too much oil and the engine won't perform as well as it could with that ratio. There are other drawbacks to the 16:1 ratio. Fouled spark plugs, clogged exhaust, etc.
Tom