Any of you builders out there have REAL dyno numbers for their yellow blue, and orange beasts? Jeff, Scooby, Knuts, Raptor720?

 

I have shown Dirt Wheels magazine, Jeffinrivercity, and Vegas703 my dyno charts that came in just shy of 70 HP in 100 degree weather. Unfortunatly, I can't get these in a format that I can post. It's an older dyno that can only give me a "view only" computer file. [DOS I think?] I've tried scanning the print out, but my scanner doesn't seem to be good enough to show it. [The print out is sort of light]. I'm trying to get a dyno of my own so I can post everything.

 

Forget Jeff, Knutz if you can afford a dyno, I want to be adopted by YOU!

 

Vegas650:
What kind of fuel do you have to run in your modified DS? Will standard 91 octane fuel work fine? Do you do much trail riding or do you just ride the dunes? Any problems riding the trails with this mod? Any reliability issues? Does it start as easy as stock?

I would like to have a bit more power but, not sure if I want to sacrafice reliability or the convience of standard fuel.

Thanks,

Mark

 

Figure on 60-63.5 hp from a good 686 with 11:1 compression, porting and chamber work, a mild cam (drop in) valve springs suggested, stock carbs, mod air box, clutch springs and a slip on (on pump gas).

Look at 70 from a 727 with the foregoing 686 mods.

Going to 12.5:1 or 13:1 compression, on the 727, with a bigger cam (some additional head and piston work, Carillo rod, special valve springs, big valves on the intake, carbs (a real pain in the ars) and a full exhaust and 73-76hp is there using VP-MS103 mixed with pump gas.

Add a stroked and modified crank, ignition system and some other features to the above 727 and just shy of 80hp is reality. At this point, I suggest switching to alcohol as the fuel. This will push your power above 80 and help the engine run much cooler. Sure your riding distance will be reduced but if you are interested in this much power--who cares.

Currently, I am beginning the building process for a turbo Craptor using a junked out Raptor as the donor bike. This system should be fun and, with the addition of fuel injection and alcohol, it will be a pleasure to tune and ride.

Of all the engine combos, I like the 686 the best. It will run and run just like stock but with tons of good clean problem free power. Obviously the big 727 has had its growing pains and does not yet have the track record of the 686. After time, I am sure it will be just as common and good running as the 686 engines. What you must watch for on any engine build is improper porting. I have seen more Raptor engines become junk because the monkey that did the port work did not understand the cylinder head design and flaws. The other area of major concern is the transmission. I have found that running a 13-41 on the 720 size engines allows the rider to avoid many of the 2nd gear issues. Eventhough the 13-40 or 13-39 gear combos can be used, if you are not running Fortin gears and have a habit of missing shifts, stick with the 13-41 and avoid getting tossed over the bars when the trans locks up.

 

Currently, I am beginning the building process for a turbo Craptor .....


Boy you sure do have a way with words Raptor720.

 

I remember when I had my first Warrior and I thought that was fast, then I rode the Raptor and the Ds and I thought those were fast, now its turbo this fuel inject that....when does the maddness end!!!!

 

I just like messing with the Raptor. It is a new product, as far as atv's go, and it is not one of those "been there done that" things like a Banshee. Like Knutz and his top quality DS work, I think it is fun to go to the races and have a conversation with people about the 4 stroke. Again, I am not in the business and on the occasion that I do take in work, it is just for friends and just for fun. I am just lucky that my day job affords me the time to spend on my hobbies. Perhaps that is why I do not have a problem posting my results and hope that I have helped a few readers. I don't recall ever seeing a "engine builder" post any helpful engine mods on any web site. I just wish that many of the people at the races could display better manners.

As for the turbo, it was the natural progression on the engine build and the injection is something I have been working on for about one year (ever since I realized that the stock carbs and even the FCR Kehins were not what I was after). Simply, the stock carbs are fine for even a build 686 but beyond that, carbs become an issue. The KEhin FCR carbs work ok but are a real pain to jet. The other problem with the FCR's is that they don't fit worth a damn and Sudco has yet to make a center pull linkage or provide a 35/39mm carb pair with the correct center spacing and for a price under $800.

On the name "Craptor," some people think that gets under my skin. In reality, I really like the name and use it often. I even plan on getting replacement stickers changing the Raptor name to Craptor. I also like the name CrackNFail for the Cannonadales (although that name seems to hold some truth). Are any of you DS guys willing to change the name of the DS to DirtDoo?? lol. Here are some of the popular sayings (in fun) "Just don't DOO it" or "Friends don't let friends DOO it"

 

I've never had any problem with the name "Dirt-Doo". After Sea-Doo and Ski-Doo, it's just a natural progresion of names.

But wait a minute Raptor720, what do you mean that you don't recall ever seeing an "engine builder" post any helpfull engine mods on any site. You hurt my feelings with that one.[lol] Are you saying that I"m not an engine builder, or that I'm not helfull?[img]i/expressions/face-icon-small-happy.gif[/img]

 

1st let me say that we should take Raptor 720 seriously. I've met hiom and he's really not a crack addict. But Jon are your dyno #'s from the old dyno at trinity, cause I've seen their ad and they advertize the 465 kit at 6hp more than my wife's made. And you were there to see that! My pet name for the DS is SAND PIG! Hey Faster, I run race fuel with the 12.5-1 piston and in my opinion, it starts easier than when it was stock. I only ride sand dunes and wide open Desert. Not too many trees in Vegas. Only problem I am having is oil out the crank case vent. BUT I had that before any mods.