That's why they have a throttle and not an on/off switch. Just because power is there doesn't mean you have to use it in every situation. It's called "driving".

 

Hey 4wheels what elevation are you at? I have basically the same setup as you and I am running in the 300's for a main jet. Thanks.

 

Dune, I ride mostly between 700 and 900 feet above sea level.

 

I'm exactly in the same boat as you. I want to go as fast as I can w/o needing to run race gas. My friend also has a Banshee & yes we did drag race on level, paved ground like 4 times. His mod was high compression head & open air box. Everything else was stock. Every time we raced, we were exactly tied all the way until he hit 6th gear then he pulled away like I was standing still. Now he's modified it to the extreame so no need for me to race him anymore cause this thing is ridiculosly fast. Anyway, if we raced anywhere other than on pavement, the scrambler got a head a little better. My mods are, HPD 12:1 cool head, HPD trail port, HPD race pipe(the skinny one that wont burn your leg) V-Force reeds, 39mm carb, Ritter air box mod, dropped 55lbs+, upgraded suspension & lowered height w/ smaller tires(lowered gearing). By the way, when running in wet conditions, I just duct tape up the RItter air box mod & I know what jet to change since there's less air. It's a quick change. 99% I don't worry about it & have no problems. I forget all the other mods, you'll have to look at them listed under my picture gallery.
Jim Maloney 98 400 Scrambler

 

I forgot to mention one VERY important thing, which is the clutching. This made a HUGE difference. Violet secondary, red primary, stock weights, & 42-36 helix. I also added the HPD 2.3 lb flywheel lightening at the same time. Man these 2 mods together was exactly what it needed, this thing runs like a wound out manual quad that want's to shift to the next gear, very quick & snappy. I love it. By the way I ride my little kids around all day long on it, follow them on their PW50 & PW80 dirt bikes & putt on trail w/ my utility riding buddies. Very versatile. Good Luck
Jim Maloney 98 400 Scrambler

 

95 Sport,
I have expierence with putting a sled engine into a quad it was a 500 ski-doo liquid cooled engine, and yes even with minimal throttle it spun way too much. I ride sleds myself and just got rid of a ski-doo formula 500 with that same engine, this thing makes all kinds of power. as back to the snowmobilg engine in a four-wheeler, i dont kno if uve rode a sled but 100+ hp is a lot to throw into a quad frame. I tried everything to not get it too spin and it was just an overwhelming amount of torque and power....i added longer swingarms beefier tires and clutching, u can not stop the spinning!!! Quads are not designed for this kind of power, the only way that will work is with a drag frame. A quad with a sled engine is not practical for anything but drag racing, there is a stupid amount of wheelies and spinning, that and u have to do a lot of frame work to fit the twin and its pipes in. As for the driving thing well, i can drive and i kno about the throttle but by putting that sled engine in it seems non-exsistant its either go or no go. Dont be stupid, be practicle...