The Scrambler is back together, and I'm no longer forced to ride the Honda as a mode of transortation at the hunting camp. It sure is nice to have something fast to ride.
Here's the Spec Sheet for the latest round of modifications:
Wiseco Piston .040+
RCR Porting
RCR Head Modifications
Rejetted carb to 300 Main Jet and 35 Pilot jet
Deburred the Delta 2 Reed Cage, reeds at low tension
Detailed the outside of the cylinder and head ( basicly removed all of the sharp edges and burrs. I cut my knuckle pretty good taking the studs out. )
I worked as a machinist for 3 years in a racing engine shop that built cylinder heads from billet aluminum for nitro and alcohol dragsters and funny cars. The first heads to run over 300 MPH came out of our shop. That, along with 20 years as a "gearhead" and building a bunch of V-8s for customers in my own garage, I do have some background in getting an engine to perform.
I knew that I had no knowlege of two stroke porting, so it was better to farm it out. Trust is important when it comes to things of this nature. I chose Rick to do the porting and head work because I knew that Rick would be the one with the tools in his hands.
The cylider and head came back on time, as promised, and the work was very well done. All of the openings were radiused and smoothed, the sanding patterns in the aluminum were constistant( indications of a professional job )and the intake port had been lightly sandblasted.
The head had been milled from 46cc to 40cc ( I checked it )and all of the machining marks looked good.
The engine was re-assembled by the mechanic the the dealer and even he was impressed with the work. He did however, neglect to put any coolant back into the engine after putting it all back together, as I discovered the next day via the high temp indicator light.
I put the pipe, reeds, spacer, carburetor and airbox back on at home ( I took all of that off to look at the noisy piston, and didn't want a bunch of non-stock parts on it when it came in for warranty work ) and it fired right up.
The midrange throttle responce is much improved, it didn't seem to loose any low end torque and the top has increased slightly. The jetting is still rich through the first tank of fuel to break it in, but after that I'll be jetting down to see what she'll really do.
A top-end blast on the paved road with a 12 channel GPS netted a 70.4 MPH top speed. I checked the GPS against the speedo in my truck, and both were within 0.5 MPH of each other.
Am I satisfied? The quad will take a little more tuning to get it spot-on, but it's even more of a rocket than it was before. The quad wants to lift the front wheels at 1/2 throttle from about a 10 MPH roll now. Yes, I'm satisfied !!! It's going to take someone with a Raptor or a stout Banshee to out run me now.

 

CaptNemo:
I dunno if you seen my post or not, but, I was thinkging about getting a SC400 4x4. As I said in the other post, I like to hunt, ice fish, and various other stuff. The SP500 is a great machine but I don't know if I can afford it, What are your expierences with the 400? I was thinkng on SLOOWLY Building it up. Do you think I will be impressed? I like going fast, one main reason I don't want to go with the SP500. Is the SC400 easy enough to throw around? What are your expierences with jumping it? Have you ever had it on a track? Do you think it would be possible for me to keep up with a RM125 on trails? Well, Sorry for all the questions, But I feel you have some insights that might make my decision a little easier, Thanks much!

-Jared

 

Nemo, have you removed the oil injection system? I only ask because I see no mention of it in your post. If you have I've used Bel-Ray MC1 and Klotz Super-techniplate in the past. It seemed to me that at 40:1 they left more residue than I cared for. I've recently switched to Maxima 927 Castor and like it so far.

I took my 400 to Rick less than 3 months old and had the same work as you describe done to it. I'm sure you will be pleasantly pleased with the newfound performace of your 400. Whats even better is that you have only scratched the surface of building a true hi-perf 400L!

Although I use a few HPD hard parts, Rick has been solely responsable for all internal motor work on my 400L. After running his "standard" port/head job for 6 months I went back to him to do a "special" port job to use with my HPD billet head. I thought the thing ripped then, it screams now!

Did he mill your head for race fuel? If not I still have my OEM head Rick did. You'd have to run 104+ with it though, if your interested in it.

I guess the next step is a 38TMX/39PWK, and some clutch tweaking?

 

Capt,

I finally got a chance to "air out" my Sport after the rebuild. WHOA! Is that sucker fast now. I opened it up in a long gravel parking lot at Michaux State Forest. I needed the gravel to keep the front end on the ground. Even with all of the wheelspin, I was able to get to a speed that almost made me soil my riding pants. Yet at the same time it is VERY controlable out on the trail. A light throttle thumb is required.

I now have the same problem as Jack did. On the hardpack it wants to wheelie to the right. The tire pressure is the same in both back tires. Jack solved this by going to a 2.5"+ swingarm. Looks like I'll have to also.

Before the rebuild, when it went south at Cochranton, I completely embarrassed a stock Banshee on a dirt road. My girlfriend Celeste will back me up on this. I do so enjoy force feeding ample servings of humble pie to those who talk up their Banshees. When we got back to the trailers, my Banshee loving friend didn't have much to say. He had been talking up his Banshee for the past day and a half and now wouldn't even say that Polaris machines were junk, because his broke down too. I love it when a plan comes together!

 

Jared, As for throwing it around, I'm 5'11 230lbs and a commercial diver by trade, I can pretty much throw around a bus. The Scrambler is extremely manuverable. The only way that the RM will get away from you is to go between two trees that are too close to get through. If you're going to work the thing unmercifully, look at the Xplorer, as it has a low range in the gearbox. It jumps well, and I run logging roads and old goat path type trails, but never on a "real racetrack". It comes out of a corner in a power wheelie everytime.
Jerry, I'm still using the injector pump with 64:1 pre-mix Polaris Gold Synthetic and giving it plenty of time to warm up. I had Rick cut the head up for 92 octane pump gas. I may have the stock carb bored ( Iknow that you had that done, what are your experiences & opinions? ) or a new & larger carb. As for the clutch, I have a plain color primary with a violet secondary with 55g primary weights. I may try a HPD6 plain spring to lower the initial engagement RPM. Are you using a girdle kit on the engine?

 

Capt'n,Initally I had the OEM carb bored to 35.5mm with the RCR air box mod. It does well for general riding, but I spend most of my riding time in large sand flat's at full throttle. The 35.5mm just was'nt up to the task. I feel that the $50 would be better applied to a 38TMX/39PWK with a K&N filtercharger. You might even be able to get a few $$'s for your 34mm from a TBlazer owner. Mike swapped his 34mm into hid GF's 250. As for clutching it all depends on what you are trying to achieve.

Mike, I hope to get my +3" Hot Seat swingarm on in the next week or two. I just got it back from being powdercoated (red). It looks really good. Everybody at the shop commented on how good the welds looked. 3" longer and 8lbs. lighter! I hope the install goes well.

Since I'll have the secondary clutch off I think I'm going to try a 44/40 helix in the roller and put a HPD red/yellow in the primary. Hmmm...maybe I should've gone with a +6"

 

WoW!
From the way it sounds, These 400's are fast! Should be plenty fast for me. I want somethining to ride, and fast! :-) With the ocaisonal tree stand haul. No big deal, I am going to look at a 2000 SC400 4x4. Anything I should be carefull of? I can't wait to get on something and ride! I am glad this thing is an auto, I broke my left foot and its in this moon-boot type thing. No shifting for me. Thanks much!

-Jared

 

What can I expect with this setup on a '99 Sport:
RCR Stage 1 Performance kit
V-Force Reed Cage
Wiseco Piston
39/42mm Carb -not sure which
ITP holeshots/T-9's

 

It will definately wake it up. Go with either the Mikuni 38TMX or Kehin 39PWK, the 42mm really isn't needed.

Simply dropping in a Wiseco won't add any power, but it will be great insurance against a premature meltdown.

To really wake these things up a good port job is in order.

 

On an interesting note , a 42mm TMX carb is basicly a modified 38 TMX carb . On a flow bench they flow identical to each other . The 39 PWK will out flow both by a small amount .