I will most likely bump up to the 13.5:1 and use the Megacycle 280X4 Cam. So I really won't know what the gain is either, but I'm hoping to drop a couple .?'s off my 300ft time. But a lot of the 300ft time is in set up, and not always about pure power. But it doesn't hurt to have a lot of hp and torque.

 

According to the KENZ bike, which was jetted for 1200 feet not the 7500 feet it was in with a stock swingarm, the Sparks bike and the Craycraft bike traded wins equally.

Apparently it takes an extra 30cc, 4mm larger carbs, and oversize valves for a Craycraft bike to run with an off-the-shelf Sparks bike.




So does everyone go to a gunfight with a knife??? If your going to race, you should come prepared to race. I really think its childish to make a bunch of excuses, I am not backing up craycraft or kenz or sparks nor anyone but manif you lose accept it and go on, if you win rub it in their face real good and make them go spend some more!![img]i/expressions/face-icon-small-smile.gif[/img]

 

I have my doubts that their bikes are off the shelf. I'm sure Curtis was aware that rapfam had a craycraft and spent a little extra time on their engines.[img]i/expressions/face-icon-small-wink.gif[/img]

 

I certainly will doubt that quote. I dont think they had time to take it to Curtis before he got the 730. The 690's were built before he got the 686 as I recall.

 

I do not have any details but, rapfam is a 105mm and not a 106.

No matter how you want to look at it, PUMP GAS true 10-1 vs. 13.5 or higher seems pretty good to me. Drop a 13.5 to 1 105mm and re run them. lol

 

RaptorFam is just a 10:1 105mm Craycraft. I can't wait to see the video's though. To see how close the bikes are now. From the video's I saw before RaptorFam would jump out of the hole on the Spark's bikes of his dad and uncle and then they would smoke him on top end.

It will be fun to see the new video's.

 

rapfams 686 was done months before his dad got his engine back from Curtis.

 

hey, Im the guy that went to the cinders with the kenz bike and raced the rapfam. I went up there with stock tires stock rims and stock swing arm, I had jetting for phoenix, and my build for my motor is different from the sparks and craycraft bike, and i went up telling the ramfam that and they didnt expect me to beat them it was my 2nd time to the cinders and i really didnt know how to set my bike up and now i do and next time i wont go as unprepared as i did this time..so hopefully i can go up there on the 4th of july and get the rapfam to go and our bikes well have the same setup ( suspension, tires, jetting, gearing)

my build:
trinity porting (that kenz reworked)
13:1 j.e. piston
trinity manifold
35 fcr carbs
bigger vavles
open air box
stage 2 cam
hmf pipe

and from what i got from the rapfam the cr bike which was very fast had a custom trinity manifold, 39fcrs, bigger vavles, sparks pipe, low comp piston, and a sparks racing cam, and dual k&n's
and im not sure what the sparks bikes have

 

I could have sworn the 690's were done first .... [img]i/expressions/face-icon-small-confused.gif[/img]

 

no the craycraft 686 was done months before the 690 nice going rapfam