The HP numbers for your current set up are probably pretty accurate, you would gain 8-10 more HPs with some CPI pipes,34-35mm carbs and clamp-ons air filters.You would also be very surprised of how little low end power you would lose with these mods.You are right about race gas, unless it is used with the matching compression is a total waste of $$$, I have seen dyno runs of low compression engines putting out more power with 93 octane than with race gas...



I can relate to that as i ran Rossier's stock stroke T-REX set up two years ago and wasnt terribly impressed with it, I too was expecting more than what I got for the money spent.In fact it wasnt any faster than my friends ported 350s, they were running 400$$ dune/race port jobs while i was running a 400cc 2000$$ top end + 500$$ port job so like I said I wasnt too impressed...For that kind of $$ i could have built a stock cylindered engine that would have annihilated their set ups, they say you gotta pay to learn...

With that said there are quite a few good shops outhere that will build a stock stroke, stock bore 90-95HP alky Banshee, you just need to deal with the right peoples.

 

I guess the stroker kit may be the key to get what I want power wise, but I'm tired of spending the money to get what I feel is mediocre results. Hell, with just a pipe and jet kit on a yfz450 you're looking at 50hp and it handles better than a Banshee. Spend a couple grand and it'll hang with or beat my Banshee on pump gas, without the worry of pre-mix. I'm really leaning towards a new 4-stroke. I like the power band much better than my Banshee,even though I can beat one. I haven't raced one, but I did ride one and it was awesome for a stock quad. It felt faster than my Banshee did when it was stock, minus top end mph. If I put the same money into a yfz, I'm very confident it would beat my Banshee. Wasn't this a Zilla page?

 

I have toyed with the thought of finding an R6 donor bike and dropping in the motor. I don't know what all has to be done to do this but the R6 puts out over 100hp stock, but then I'm limited to a drag/dune only quad. Then I would haveto make homemade parts like exhaust, motor mounts, etc. I don't know that I want to do that, but it is an idea. I can only get $2800 trade in on a YFZ at my dealer, so dropping a few grand on a R6 donor does sound appealing, but I don't know enough about the conversion process to do it. I could probably sell my Banshee motor alone for $2,000 with the pipes and other parts, if not more. Just an idea, but I don't think it would be the every day rider quad I have now. It's amazing what the quest for speed does to the human brain.

 

You can have a big monoblock stroker built that will put out a pretty reliable,rideable 100hp on pump gas and unless you are able to do the machining and fabrication to go with the 600cc bike engine, the monoblock will probably end up being cheaper.

 

Well the 500 popped. It needs to be bored and rebuilt. Any suggestions as to where, how, who, to do this work. Any suggestions. Thanks.

 

Check out WWW.TRINITYRACING.COM
They have some nice rebuild kits for the Zilla. As long as nothing is cracked or needs maching, put the kit in yourself (provided you are somewhat mechanically inclined). It is not hard at all and you'll save money not having to pay for labor. I have never owned a Zilla, but I helped a friend put a new top end in his a few years ago and I was amazed at how easy it was.