[MachZ990]

Just got back from a lake in southern Wis. where I put about 20-25 miles on my sled for the 1st time with the RK Tek head. My sled now has about 150 miles on it. I will tell you what I saw on my first weekend riding it stock and then what I saw today with the head installed.

First weekend rode approx. 125 miles in southwest Michigan south of Grand Rapids. Snow on ground was about 16 inches of lake effect snow (sugar) and the temps were in the mid to low 20''s. Elevation about 800 feet above sea level for all riding. Sled would tach around 7800 wide open on clicker 3 (stock position). After about 100 miles I tried opening it up on a road and it went to 90 mph real quick and then tapered off and started to creep higher. I had to shut down before getting much higher. After that weekend (about 2 weeks ago) I put the sled back in the garage until today.

Today''s run was with new 500 mains installed, the RK Tek head and 96 Woody''s 1.325 studs. Otherwise bone stock. Sled had 130 miles on the odometer when I hit the lake. Temp was between 16 and 20 degrees F. About 2 inches of slightly packed snow on the ice which packed down to about 1/2 inch. I warmed up the sled and then hit it a couple of times for about 1/8 mile and then checked the plugs. Perfect cocoa brown color. Then I ran her for about 1/4 mile and out of the hole it would hit 8000 and then drop to 7800 or so and then climb rather quickly back up to 8000 and then creeped to almost 8100 rpms on top. Sled did 105 in about 2000 feet. I dropped clickers to 2 from the stock no. 3 setting and the rpms would drop to 7600 and then climb to 7800 and slowly creep to almost 7900 but not quite. This time I taped it for 1/2 mile and saw 108 mph on the speedo. Sidenote - When I got off the packed snow and into the loose snow the tach would hang around 7600.

This info is for you to decide. How much did the head do? How much did the 500 mains do? How much did the lake do in comparison to the trail and road riding in Michigan? My sled now has 150 miles. The chip is not burned in yet so my timing is still retarded and the motor is still tight. I am not adding any weight to the clutch at this time and I have gone down one clicker from stock but in my opinion it is just pulling that clicker position. I have a new Dynoport pipe and can to install next after is comes back from Jet Hot Coatings. I will post what I see with the pipe installed when I get it.  

 

[bonzi]

Most of the gain you mentioned is from jetting down which is the advantage of the RKTech head, I'm running 450's and friends are running 430's, You can save your money on the pipe and can, they make almost no differance, instead install a restricter in the stock pipe.  

 

[rotaxlover]

Do you feel that the sled got to 90 faster with the mods? It sounds like the conditions were fairly similiar. Hard pack road or lake with 2" of fluff. Are you running any clutch mods other than clicker position? Seems like the RK Tek head is working good. Would you agree?

 

[MachZ990]

My plugs as mentioned above looked about textbook perfect. I can't imagine jetting down any further than 500s at this point.

 

[MachZ990]

I've heard mixed reviews on the pipe and can.  Some swear it works and others don't see much.  Dynoport pipe and can ran good on my 00 700.  Apparently the 01s only saw about a 4hp increase with the Dynoport pipe and that equates to about 2 hp at the track.  I have been told by several sources that the 02 responded better to the new pipe and can and there is an 8 hp increase or 4 at the track.  That you can feel.

 

[Gunner]

Did you check your wash? I'm running 410-430 mains
now depending on temp and my plugs didn't look
much different from 460 on down. My EGT's readings
at WOT are 1175-1200. Midrange is the problem.

 

[Roton]

Just for comparison purposes, I'll tell you what my stock, except for Dynoport pipe and canister, '01 800X did before and after the timing breakin last year. Before the timing changed, with about 3 hours on it, I was gunned at 109.4 MPH in 2000 Ft. This was without the pipe and canister, bone stock except for 192 Woody's in the stock 1" X track. Conditions were 200 ft MSL, hard pack of 2 inches on top of ice, medium roughness granular snow, OAT was 25 degrees F, no wind, clicker on 3. Out of the hole, 7900 RPM, dropping to 7600, then creeping back to 7700-7800 RPM. I glanced at the tach up to about 80, where I payed attention to more important things.  The next run, my buddy did 110.0 on his 300 mile brand new  '01 ZR 800.

After I put on the pipe and canister, still stock jetting, under similar snow conditions, with the timing advanced after about 500 miles, same place with OAT at about 15 degrees F, I ran 111.3 MPH, but the snow was bumpier, so I don't know how much this affected it. Clicker was still at 3, RPM's went to 8100, back to 7800 and crept back to 8000. I have yet to check tach calibration. Plugs were cocoa brown after several runs, all of which were within < 1 MPH. Gun was calibrated Stalker ATS with STATS.

 

[MachZ990]

Roton, Sounds like you are running the about the same as most 800 twins that I have driven or come up against (with my 00 700).  I haven't raced this one yet.  Several people on amsnow forum are saying 120, 122, etc. for top speed.  I haven't seen a stock or lightly modified twin of any of the brands go that fast unless downhill with a tailwind.  Didn't want to get off subject as I am still interested in hearing from more people.  Thanks for your input.

 

[Roton]

Yeah, my sled will go 122 and accelerate to 60 in 2.75 seconds when I ride it off a cliff. I had an '00 700 too and it went real well. In certain ways I like it better than the '01 800x, but oh well. Good luck in your persuit.

 

[MachZ990]

Went out again today. Same lake. Temp 12-16 F. Friend brought same sled as mine (02 800x) stock with 500 mains.  He has 350 miles and chip burned. Mine 150 and chip obviously not burned yet.  Both running clicker 3.  His sled comfortably faster by at least 2 mph on top.  His sled pulled harder through upper midrange and top end.  I saw no advantage to head today however I will wait until I get over 300 miles and the chip burns through to decide.

 

[Gunner]

What was your compression before and after the head?

Are you both running the same track? I see 1.325 studs.

I've never seen any difference after my chip burns
in. I've heard others say - "wow, hold on" and all
that, but personally, I've never seen any difference
on 2 different sleds.

I'm seeing similar results right now, but I believe its
in the clutches - which I'm working on. I can pull on
a stock 02 out of the hole and midrange, but lose
it on top end. I suspect belt slippage as my clutches
never get below a 1.2 ratio. We'll see this weekend.

Your buddy may have a great 02... Did you measure
your deck height when ordering the head? The only
other thing to do is to swap heads (assuming your
deck heights are very close and most 02's were) and
try it.

 

[MachZ990]

Gunner,  Compression was 135 stock and 141 after head installed.  Thats cold with 3 pulls on the rope.  If I pulled 5 times on the rope with the Rk Tek head the compression peaked at 145.  Yes both sleds running 1.25 track.  Mine an OEM Ski-doo track and his is the predator 1.25.  Both are clipped every third window.  Both 96 studs down middle.

 

[kid rocker]

MachZ990, where in SW Michigan did you ride?  Grand Rapids area?