OK...As some of you may know, I have 2 bone stock Prairie 700's - one for me and one for my wife. I bought a Dyna CDI and installed in mine and said that I would do some tests as I made mods.

Well, the new CDI kicks butt! I ran my machine against my wifes 4 times on dry pavement from a dead stop. I had a friend of mine ride my wifes bike for the first two runs. I had that stock bike from the moment we hit the throttles. We both had to feather our throttles as we took off, but when the frontends settled out, I was steadily pulling away. In those two races down our street, I beat him both times by about 4 (yes, 4) bike lengths. We probably ran 400' or so.

For the next two runs, we switched bikes. I let him ride mine and I rode my wifes. Wanted to be sure the big difference wasn't in driving skill, luck, or my big a$$. I weigh 245 and he probably weighs 170. Well, we made the same two runs again, and he smoked me by about 4.5 lengths both times.

That module really wakes that 700 up!!! You can actually feel it just putting around the yard. It is as if it frees the bike up somehow. After you ride one with a module, you realize that the stock module just doesn't do that engine justice.

Now, on to my question. I have my bike torn down in the garage right now. Pipe and muffler are laying in the floor. Plan on doing the NYROC mod to that bad boy in the morning. 6 3/8" holes and remove the little baffle thing in the end. Also have a NAPA 7335 on its way. Should be here in the morning also.

I couldn't wait, so I put a 145 in the rear carb and moved the 142 to the front carb. I also bought a 148 just in case. I plan on shimming the needles also - maybe .020"-.030".

I am at maybe 200' above sea level. Do you guys think I will be where I need to be with 142/145 or should I pull the bowls back off while they are so easy to get to and go 145/148?

Any input would be greatly appreciated.

Two side notes - Yes, I will run them against each other after I complete my mods to let you guys know what difference the intake and muffler mod make. Also, I never had a problem out of any of the 8 bowl screws. I held the carbs with one hand and the screwdriver in the other so that I could put lots of pressure into the screws as I broke them loose. No problems at all.

 

thanks for the info!!!
you are luckier than most with the screws....but next time ya have em out....i would replace them with socket head cap screws 4x14mm...and use a little anti sieze on them....about the jetting.....they are all a little different....i would try the 142/145 combo and fiddle with the mixture screws first....then after plenty of patience....if its hesitating on WOT from a dead stop....look at shimming...or changing to larger primaries....with just the nyroc mod....142/145 will probably be a good starting point....and if ya do the screws like i said...its no hassle getting back in to the bowls.....hope this helps!?

 

What speed were you running at the end of the runs? I am interested because I have done similar tests between a stock and Holeshot Prairie 700 from 10 to 50 MPH and the Holeshot pulled the stock Prairie 2 lengths, about 11 ft. We did some runs for fun from 0 to 60MPH, and the Holeshot 700 pulled about 3 lengths when we could keep the front end down at the start which was nearly impossible. If the new cdi pulls 4 lengths, I would like to see it run against a Prairie with an offset key and the new DG3 device which is supposed to work over a much wider RPM range. Should be interesting.

I know the cdi doesn't have reverse limiting, or the anti-theft feature the stock one has, but what about the tilt sensor safety? Does it cut the engine and fuel pump off when it tips over on it's side about 60 degrees? Thanks for the info.

 

P633,
FYI: You might be interested to know that I have ordered the new cdi (back on 3/22) and as soon as I get it in my hands, I plan to run timed tests (at 100' and 300') to compare the new cdi to my DG holeshot (the original version). This comparison should give folks a better idea of how much different the original DG holeshot is to the new cdi.

Happy trails...[img]i/expressions/face-icon-small-smile.gif[/img]

 

That should be interesting.

 

2P700's- Excellent post amigo.

According to my tracking# our two should arrive tomorrow. This is going to be a GOOD Easter!!!!!

 

At the end of the 400', my bike was running about 47-48 mph. I am not sure how fast my wifes was running. On the last two runs when I was driving it, I was looking at how far ahead my bike was.

I just finished my NAPA hose, NYROC mod, and re-jet /shim. The hose went on just fine. The muffler mod was a different story. I decided to drill 6 3/8" holes. On the 5th hole, drilling through the last baffle - SNAP! I broke the damn drill bit off in the muffler!!!! I got another bit and drilled the 6th hole - but this bit was a little longer. Yep - I drilled straight out the back of the muffler! Not a good day as far as the muffler mod goes. I couldn't get the broken piece of bit out - it was about 5" long. I could hear it rattling around in there, then it lodged against something. I didn't want to cut the muffler in half or start tearing out baffles to try to find it, so I left it in there. I did not hear any rattles while I was riding, so maybe it has found a home in there.

I went with the 142/145 combo and .020" under the shims. I never touched the mixture screws. IT RUNS GREAT!!!! I would say that the NAPA hose and muffler mod along with the jetting added about 75% of what the module alone did. The three mods together are awesome. I'm ready to kick some butt now!

I went back out and ran the 400' again a couple of times. I was running between 53 and 54 mph in the 400' with the three mods. Kinda hard to hold on to. I have figured out how to lay into the throttle smoothly from a dead stop and carry the frontend about 6" off the ground during takeoff. Once you get to where you can repeat this, the takeoffs become pretty consistent, which makes for more repeatability in the test runs.

Still haven't pulled a plug, but I bet I am pretty close since it no bogs or hesitation.

Thanks for all the help on the hose and jetting issues that I was having. To those who are thinking about doing it, but aern't sure about tearing into your machine - don't be afraid. It is really not that bad at all.

 

I meant .020" under the NEEDLES, not the shims:-)

 

142/145 should be about right for the NYROC mod. There seems to be a fair number of people with that setup. That's what I was running with an HMF half system. If you decide to go to a full exhaust system you'll want to go 148/145.

No go play with some Grizzlies, 400ex's.........