KAWASAKI SXR 800 – GROUP K PERFORMANCE MODIFICATIONS

 

An Overview of the SXR 800 - The Kawasaki SXR 800 offers a quantum leap it in handling over all other stand up crafts.  The SXR is not a modified Sxi750 hull, but rather a completely new design.  Among other things, this new hull allows for hard acceleration without inducing the porpoising that other stand ups exhibit (even with heavier riders).  The longer and wider hull, along with a wider tray easily accommodates larger and heavier riders better than any other stand up.  The “nose down” general ride of the hull makes for very responsive turning with much less effort.  These handling qualities are so profound that the SXR has instantly become “the boat to have” for anyone competing in IJSBA closed course racing.

   The SXR engine and pump are only slightly different from the SXI 750.  The SXR has 82mm bores (782cc) and milder port timings than the 750s.  These changes work together to offer a big increase in acceleration over the old 750, without compromising peak speeds.

 

Our Kits

Swift Kit (89 octane) – A lower octane kit that makes a big increase in acceleration along with a modest increase in peak speed.  Ideal for the recreational rider who want simplicity and affordability.

 

Sleeper Kit (91 octane) -  This pump gas kit offers a serious increase in acceleration and peak speed while retaining the stock pipe, ignition and inlet system.  The engine looks and sounds like a stocker, but easily runs with Limited class Super Jets.  The lower peak rpms mean stump pulling torque, exceptional long-term reliability and much better fuel range than higher revving setups.  The ideal boat for wave jumping, buoy riding, and aggressive recreational shredding.

 

Hammer 1 Kit (91 octane) - This is the fastest and strongest accelerating pump gas package for the SXR.  We spent months doing the fine-tuning that allows this affordable 91-octane package to attain speeds that used to be the sole territory of full-blown race gas machines.  Still retains the stock water box, and low sound levels that go along with it.  Definitely a machine for the very fit and aggressive recreational rider. 

 

Hammer Kit 2  (105+ octane) – This package is identical in every way to Hammer 1 kit, except for the addition of the 6-degree ignition advancer plate, and the steeper Skat 15/20 swirl prop.  The extra timing gives a huge boost to bottom end acceleration, and the steeper prop allows for higher speeds.  This is the most cost effective competitive racing package that money can buy.  105+ race gas “only”.

 

Super Stock 105 - A no holds barred race gas package that is suitable for top-level IJSBA closed course competition.  For the rider who demands the best of everything to go as fast as possible.

 

 

$Engine   /    $Pump

Speed

RPMS

Impeller

Ride plate / grate

Stock

 

47-48

6480-6550

OEM Stock

OEM          OEM

Swift Kit

$  275.             $277.

49-50

6620

9/17 C-75 Skat Trak

OEM          OEM

Sleeper Kit

$  660.             $277.

53-54

6980

9/17 C-75 Skat Trak

OEM          OEM

Hammer     (91oct)

$1490.                 

55.5

7810

OEM Stock

OEM          OEM

Hammer     (91oct)

$1490.             $407.

58-59

7580

14/19 Skat Trak

Worx          OEM

Hammer 2 (105+oct)

$1537.             $407.

61-62

7550

15/20 Skat Trak

Worx          Worx

SuperStock 105  (oct)

$4203.           $1793.

62-64

7740

15/20 Skat Trak

Worx          Worx

 

About the New SXR Hull and Radar Testing

  As mentioned above, the SXR hull runs through the water with a strong “nose-down” attitude.  While this quality is great for turning and handling, it has a significant negative effect on peak speeds, as measured by a radar gun.  During our testing, we paced along side our SXR Hammer at different speeds (on glass) to observe how much of the hull was in contact with the water.  At 25-35 mph, the “spray line” coming off the bottom of the hull started at roughly the middle of the hood length.  But as the rider applied full throttle, the nose of the boat drove down noticeably, and the spray-line moved about a foot and a half forward.  This extra water contact, at high speed, causes a significant loss in peak speed ability.  Out test riders all said that they got the sensation that the rear of the hull was lifting at high speeds (thus driving the nose down), and they could see the spray line moving forward.  There are plenty of tricks to “lift” the nose of machines that have this problem (nozzle wedges, ride plate machining, etc).  However these mods served to “undo” some of the great turning and anti-porpoising qualities of the SXR hull. Perhaps the most effective solution is to use a trim nozzle that aims upward to allow less water contact at high speeds, and full downward to mimic the stock nozzle position for turning.

   While installing a trim nozzle would allow us to cheat our way into extra speed, we opted to do all our testing with the non-trim nozzle setup (as we presumed that “most” rec-riders will not opt for a trim nozzle kit).  All of our test riders agreed that the stock ride plate drove the nose down excessively hard at nearly all speeds.  With that, we installed a Worx ride plate.  The Worx plate drives the nose down “less hard” than the stocker, but still retains plenty of the strong nose-down ride that makes for good turning and no porpoising.  With the Worx plate, our test riders could hang off the back of the foot tray with much more control and security.

 

Compression -  All of our modification kits utilize an increase in compression ratio.  For all the kits except the Hammer 105) we opt to modify the existing OEM cylinder head instead of replacing it.  We machine the surface of the head, and then recut the squish bands to diameter.  Contrary to what some owners believe, the stock head has very good cooling properties that are easily up to the job of any pump gas format.  In addition, The stock head gasket used in conjunction with the modified OEM head, has the excellent long-term sealing properties that are desired by most recreational riders.

  Many of the aftermarket “girdle” type cylinder heads are manufactured to be used with no head gasket.  These heads are machined to accept large diameter “O” rings to seal the water jackets between the cylinder and head.  This system can offer great convenience to owners who regularly remove the head for the purpose of inspection or compression changes (in the case on changeable dome heads).  The other big plus to the “O” ring setup is that it significantly reduces squish clearance without having to machine the top surface of the cylinder.  This “O” system is the stock means of head sealing on most Sea Doo and Polaris engines. 

    It should be understood that an “O” ring can easily seal water away from the cylinder bores, however no “O” ring is strong enough to seal back the pressures of compression.  “O” ring setups depend on two absolutely flat metal-to-metal mating surfaces on both the cylinder and head to seal compression.  The absolute flatness of these two surfaces is fundamental to maintaining a lasting long-term seal.  Herein lies a problem with some “O” ring setups.

   As you closely inspect the flatness of a top cylinder surface of a 750, you will often find slight high spots on the top deck surface around each of the threaded stud holes.  These high spots are caused by the unthreaded shoulder of each stud pressing against the top of the threaded hole (when being installed).  On a conventional head gasket setup, the thickness of the gasket can easily accommodate this surface irregularity.   However in an “O” ring only setup, it can happen that these many high spots around the studs can make it very difficult for the head surface to fit flat and solid against the cylinder top surface.  Imperfections of this kind can swiftly lead to a compression leak.  At Group K, we lap each cylinder top surface to eliminate these existing high spots.  This lapping process does not remove material from the cylinder, but rather it just removes the “high spots”.   For “O” ring setups, we recommend lapping of the cylinder top surface after every 10-15 racing hours to assure optimum head sealing.

   For the more intense (and higher revving) race gas kits, there are other considerations apart from head sealing.  Most notably are the concerns of providing added support to the cylinder mount points.  When the output of the SXR engine is increased by huge margins (as is the case on the Hammer 105) there is a tremendous increased load on the cylinder base mounting points.  Over time, those increased loads can cause the cylinder casting to fracture around the base bolt mounts.  In an effort to reduce these loads at the cylinder base, the KMC race team uses a “girdle” type cylinder head.  These aftermarket “girdle” heads are manufactured in a way that accommodates very long base studs.  The nuts for these studs tighten against the top surface of the head as well as the base mount points of the cylinder.  The technical intent is to hold the cylinder to the cases via “capturing” the cylinder between the head and the top crankcase.  This then reduces the loads that the cylinder mounting points are subjected to, and thereby “reduces” the likelihood of cylinder base fracturing.  It should be noted that these girdle heads are not a complete “fix” for the cylinder fracturing issue, however they do appear to be the best available solution that conforms to IJSBA competition rules.

  Another addition concern for SXR owners using “O” ring heads is the sealing surface width.  Most 750 head were made to accommodate the 80mm bore of a stock 750 motor.  However if the same basic pat is adapted to the 82mm SXR motor, the sealing surface between the bore diameter and the “O” ring can become dangerously narrowed.  R&D will be making their cast girdle head kits available with larger domes and larger “O” parameter grooves to allow wider sealing surfaces on the larger bores.  Given this, we recommend only the R&D cast head with girdle kit.

 

Pump Gas Inlet Systems

Carbs -  The SXR comes stock with 40mm Mikuni “I” body carburetors.  .  In truth, these carbs are not a true 40mm as stated.  The actual minor diameter at the venturi is about 2.5mm smaller.  For all our pump gas kits, we do a “true bore” modification to make the carbs a true 40mm.  With this mod, the carbs still offer easy starting, steady idling, and strong overall carburetion.  This affordable mod is ideal for the occasional racer and high performance recreation rider who doesn’t want the high price or temperamental tuning that comes with many larger carbs.

Inlet Manifold -  The stock SXR inlet manifold has well designed passages that make it an excellent part for higher performance applications.  It’s only drawback is the cast in crossover passage that exists between the two inlet runners.  This passage is originally intended to offer smoother low speed response for the stock, lower rpm, configuration.  Unfortunately, significant changes in port timing (as in our kits) have a big impact on inlet “signal”.  The end result is that this crossover passage contaminates the clarity of inlet signal at high rpms.  This contamination causes inlet signal to progressively weaken during a long full throttle run.  This progressively weakening signal results in a progressive leaning out that can result in detonation damage to a piston.  With the Sleeper and Hammer Kits, we block this passage with a high-grade epoxy, and then install the correct carb jetting for the true bored carbs and the blocked inlet manifold.

  Reeds – All our Pump gas kits utilize the stock reed cages and petals.  There are many aftermarket reed petals available for the stock cages, however we have consistently seen the best long-term performance and wear using the stock OEM reed petals.  The larger reed cages (R&D M16 & V-Force) can have merits on setups that use 46mm or larger carbs, but they offer limited increases when used with the 40mm true bore carbs of our pump gas kits.

Air Inlet - The stock SXR flame arrestor is a design that offers excellent protection from water in the engine compartment, and can offer very adequate air inlet access.  For all our pump gas kits, the stock flame arrestor can be used (with the rubber silencing nozzles removed).   For owner who is not concerned with excessive water exposure in the engine compartment, there is a small advantage from installing individual “pod” type flame arrestors.  We prefer the R&D or Tau Ceti arrestor kits.

About Fuel Consumption -  For many riders, fuel range is a big consideration.  Our kits that retain the stock exhaust system will offer range very close to that of a stock machine.  The installation of the Factory Dry Pipe certainly makes for a huge increase in power, however it also nets a big increase in fuel consumption.   One of our tests includes a 24-mile partial throttle cruise on smooth water (actually our break-in run).  The Hammer 91 kit consumed every bit of the 5-gallon fuel load to complete this ride, while the Sleeper still had a third of a tank left after the same ride at the same speeds.  We would presume that running the Hammer Kit at higher speeds (or using larger carbs) would considerably increase this rate of consumption.  To be sure, The FPP pipe equipped Hammer is “a lot” faster than the stock pipe Sleeper.  However for riders that don’t intend to spend much time over 52 mph, the added range of the Sleeper could be an important quality.

 Fuel Inlet - All our pump gas engine setups utilizing the modified stock carburetors can easily retain the stock fuel plumbing and petcock arrangement.  However setups using 46/48 carbs cannot get sufficient fuel supply through the stock fuel line plumbing.  For these large carb setups, the stock fuel pickup/valve assembly must be replaced by a large diameter, direct feed fuel pickup.  Such a pickup is made by Cold Fusion, and used by the KMC racing team.   We strongly recommend that these fuel pickups be used on any machine with 46/48mm carburetors.

 

Cylinder Porting - One of the big design changes between the SXR and the previous Sxi750 motors is the cylinder port timing.  The SXR has considerably milder port timings than previous 750 motors for two reasons.  First, the milder timings allow for lower emissions to help make “50 state” marketing easier, and second, allowing for improved low range acceleration characteristics. 

  In the past, cylinder porting has received a bad reputation for making machines unreliable or “high rpm” biased … and that may be the case for poorly executing porting.  The porting modification we do for our Sleeper and Hammer kits is intended to increase power right from the very bottom of the rpm range to the top.    We spent many weeks testing to find the combination that works best for our SXR kits.  The end result is porting that offers great overall power as well as exceptional long-term piston and ring life.  Please note that we typically prepare ported cylinders and modified heads as matched pairs so that we can assure the correct squish clearances and compression ratios for the fuel octane you will be using.

 

About Displacement and Pistons -  The stock bore diameter of the SXR is 82mm (781.2cc).  Limited Class and Super Stock machines are permitted to overbore to 82.9 mm (798.4cc).  Before 2002, the IJSBA restricted Superstock machines to 785cc.  For the old Kawasaki 750, that allowed a bore diameter of 82.2mm (an 82.0 mm piston running at max clearance).  In 2002, the IJSBA rules permit 800cc maximum displacement.  .  It bears noting that Wiseco already had available 83mm pistons, but they yield a final displacement of 800.3cc, and are not be permitted in IJSBA competition. This means that an 82.9 mm piston (with average clearance) would fall just below 800cc.  These 82.9mm (as well as 82.5mm) pistons are available from Wiseco in a “racing” version.  These racing pistons feature a cutaway skirt, boost port feed hole, and thinner rings.  We have had excellent results with these pistons, and strongly recommend them.

  The steel sleeve in the stock SXR cylinder is thick enough to safely accommodate pistons up to this diameter, however the overall integrity of the cylinder block is slightly weakened by the lost bore material.  Given this, the bore diameters can become affected by attached parts.  In particular, the installation of the threaded studs into the top of the cylinder block can create high spots on the bore of a stock cylinder.  As the cylinder sleeve gets bored, this effect becomes greater.  The same applies to the installation of the exhaust manifold studs and the torque forces of the installed exhaust manifold.   Since the FPP exhaust manifold is a substantial casting, torquing it on to the cylinder can also slightly deflect the bore diameters.  For stock cylinders of average clearance, this is no problem.  However whenever boring a cylinder (particularly to the 798cc diameters), Group K will require your exhaust manifold with fasteners and the complete top stud set, so they can be installed and torqued prior to final cylinder sizing.  This will assure a much rounder bore with no high spots.

 

Cooling System -  Generating more power means generating more engine heat.  To contend with this heat, our Sleeper and Hammer kits include a cooling upgrade that significantly reduces top end engine temperatures.  An additional water outlet fitting is provided with our kits to work with this upgrade.

 

Exhaust / Ignition System -  The changed cylinder porting layout offers a considerable challenge for those tuning the SXR for IJSBA Limited class competition …. And those making tuning parts for that application.  In particular this was a significant challenge for the development team at Factory Pipe Products.  They were faced with the job of making a good high rpm pipe for a cylinder whose port timings were not “co-operating” well.  In order to make a pipe that delivered good overall power on a completely stock machine, the technicians at Factory Pipe included the use of a 7-degree ignition advancer plate (supplied with each FPP SXR pipe).  The additional ignition advance of this part makes for big increases in overall power, without having to increase compression at all.  The FPP pipe, with the 7’-advancer is a 91-octane safe setup, so long as there are no other modifications to the machine.  When we developed our 91-octane Hammer kit, we opted to not use the advancer, and get our bottom end power gains with cylinder porting and compression.  With stock ignition timing, we could increase the compression by a big margin, and still remain 91-octane safe.  Since the OEM ignition has its limiter at 8000 rpm, a limiter mod is not required.

  For our Hammer 2 Kit, we merely install the 7’-advancer plate that comes with the FPP pipe.  This combination makes a lot more overall power … and heat.  The detonation risk of this setup is much too high for 91-octane, and so 105+ octane is required to control combustion temperatures and avoid detonation.

    The stock SXR ignition flywheel works well, but it is not a particularly lightweight part.  Reducing the weight of the flywheel rotor can noticeably improve the quickness of throttle response.  This is best done in two different ways, lightening the stock flywheel, or switching to an aluminum replacement.  The logical choice would seem to be simply switching to the lighter aluminum part, however many stand-up riders have found that an extremely light flywheel can offer response that is almost too quick for controlled recreational riding.  That is, the lighter flywheel can allow the engine to accelerate so quickly that it creates more difficult throttle control and more violent porpoising (under acceleration), making the boat more difficult to manage.  Riders call it a “light switch” feeling which refers to the “all on or all off” feeling of engine operation.  The heavier stock flywheel actually helps to dampen that light switch effect to allow for smoother throttle control.  An effective middle ground between the aluminum flywheel and the stocker is slightly lightening the stock ignition flywheel.  Group K ignition flywheel lightening only reduces the flywheel weight by about .6 pounds, however the effect is significant because that weight is taken from the outer diameter of the flywheel where it hurt the inertia the most.  More weight can be removed from the flywheel, but our testing showed that the long-term life of the flywheel became questionable with excessive lightening. In addition, this mod is a bit tricky because the trigger lobe on the flywheel OD cannot be touched.  We strongly recommend the stock flywheel lightening for all Sleeper and Hammer kits.  Note: no flywheel modifications are permitted in IJSBA Limited Class racing.

 

About Oil & Fuel -  Kawasaki recommends a premix of 60:1 (10.5oz/5gall) for the stock 6500rpm SXR.  For our slightly higher revving Sleeper kit, we recommend 40:1 (16oz/5gall).  For our much higher rpm setups that use the Factory Pipe, we recommend a 28:1 premix (23oz/5gall).  The exceptionally high rpms of the Hammer setups require the added lubrication to protect against the extra heat, and the higher surface speeds of all the moving engine parts.  Contrary to belief, the added oil in these higher revving setups does not significantly increase smoking or plug fouling … and it is the best “reliability” insurance you can buy.

   We are constantly approached by owners who are trying to craft a way that can allow them to get race gas horsepower, without having to run expensive race fuel.  Sadly, it just can’t be done.

  Normal “octane boosters” are capable of making really poor gas into decent gas, but they cannot make good gas into race gas.  That is, normal boosters can make 86 octane to 89.  However the same booster can only make 91 into 91.5 or 92.  We discourage the use of octane booster except in emergencies.

  One alternative used by many is to run aviation fuel (aka “av gas).  Av gas is usually around 100 octane, but av gas has other properties that are important.  One of the main qualities that makes av gas desirable for aircraft use is that it is actually lighter (per gallon) than conventional gasolines.  This reduced weight is important for small underpowered planes that need to be as light as possible to take off.

  Normal gasoline molecules have two “ends”.  The “light” end of the molecule ignites easily, and burns with a quick low temperature flame (as a piece of newspaper would burn).  The “heavy” end of the molecule is harder to ignite, but burns with a much hotter flame (as a log would burn).  To make av gas lighter, the heavy end of the molecule is omitted to reduce the weight of each gallon.  Since most aviation engines are low rpm motors, they experience little power loss.  However if 100% av gas is used in a high output pwc engine made for race gas, there is a visible loss of power because the “heavy” ends are not there to contribute to the making of power.  All that said, we consider it a great idea to mix 50/50 av/91oct fuel for “Hammer 1” kit owners who want a little extra temperature protection during exceptionally hard operation.  A 50/50 mix still contains enough “heavy” ends” to allow for good overall power and has a much-improved octane over straight 91-octane.

 

Engine Lower End   The crankshaft and crankcases of the SXR have generally proven to be very sturdy and reliable components, even in high performance applications.  For most recreational and local level racing uses, the stock crankshaft can be safely used without any special preparation.  However, for any race gas platform, we strongly recommend that the crankshaft be trued and welded (cranks with less than 50 hours would not require rebuilding).  It bears noting that the cranks of all SXis are manufactured with the crankpin and inner flywheels as one.  In the event of crank pin wears or becomes damaged, it is best to install a new inner flywheel manufactured to accept a separate crank pin.  After this mod, the crank will be completely rebuildable (this mod is Limited and Superstock Legal).  

    The IJSBA rules permit crankcase porting on Superstock class machines (not Limiteds).  Case porting by itself does not offer a huge increase in overall performance.  However on more heavily modified Superstock engines running larger reeds, case porting can definitely help the reeds to better meet their potential. 

General Assembly -  Air Leaks - Your assembled engine should be internally air tight up to 8 psi.  New engines pass this test with no problems.  However engines with older deteriorated crank seals or brittle intake gaskets can allow outside air to leak into the lower end during operation.  This "air leak" can make the fuel mixture lean enough, at high rpms, to cause a piston seizure.  “Every” SXR engine being modified for higher performance should be pressure tested to assure that there are no air leaks.  Pressure testing is a standard procedure for all engines assembled at Group K.

 

Props and Pumps -  The pump of the SXR is basically the same as previous Sxi models.  There is some disagreement whether best results come from a “smaller nozzle smaller pitch”, or “larger nozzle, larger pitch”.  Our testing showed nominal differences, but the test riders seemed to "prefer" the acceleration of the taper bored 80mm nozzle.  With that, our impeller selections are intended for that diameter.  It bears noting that choosing the ideal pitch is not just about peak speed.  While testing our Hammer 1 package, we got the best speeds turning the Skat 15-20 to 7490 mph (60.3mph).  However the overall acceleration of the Skat 14-19 was so much better, we considered the small loss in peak speed to be well worth it.

  For most high performance recreational applications, the stock SXR pump assembly works fine.  For owners that want to “fine-tune” the stock pump, we recommend pump blueprinting.  This pump blueprinting does not increase smooth water peak speeds, however it can make a noticeable improvement in rough water hook-up ability.

   For more serious racers, the stainless steel Skat Trak 12 vane “C-75” 140mm pump assembly is the last word in pump mods.  This pump assembly offers incredibly good rough water hook-up that cannot be matched with any other pump setup.  Since the IJSBA rules mandate that a stock pump “housing must be retained, Skat Trak installs their stainless steel insert into your pump case, hence your pump case “core” is required for this modification.

 

Hull Preparation -  Our SXR test boat ran faster speeds than any other stand-up machine we had ever tested with.  With that, we experienced handling issues we had not seen before.  One expected problem was that it became increasingly difficult to steer the boat perfectly straight during radar testing on glass water.  The other problem was the boat “pulling” to the right at speeds over 58 mph.  We eventually presumed that the pulling to the right was connected to the rotational torque of the engine and prop.  The installation of handling parts (ride plates, grates, etc) seemed to make little difference.  With that, we tried a different approach.   Tests we had conducted with other machines showed very positive results from using 30-40 grit sand paper to create deep full-length “scratches in the hull’s bottom surface.   All the sanding strokes should be front to back (continuous) for the full length of the hull.  Properly done, the deep, full length, scratches should eventually eliminate any part of shiny surface.  While this preparation may not look attractive, these scratches will act as thousands of small rudders that will make the hull track “a lot” straighter in all water conditions (especially at high speeds).  These scratches can also allow for much better surface holding in high-speed turns.  This hull sanding prep made a big improvement of the straight-line control.  We consider this preparation to be mandatory for any Hammer kit or Super-stock machine.

 

Swift Kit

 

Carb “true boring” and jetting 

195.00

Cylinder head Modification (92 octane)            

90.00

Skat Trak C-75  9/17 Impeller

298.00
Exit Nozzle Taper Boring 55.00
   

 

 

Sleeper Engine Modification Kit                

660.00

Includes :

 

cylinder porting & decking

 

exhaust manifold matching          

 

cylinder head modification

 

Inlet manifold modification

 

carb “true” boring and jetting)

 

cooling upgrade

 

 

 

Skat Trak C-75  9/17 Impeller

298.00
Exit Nozzle Taper Boring 55.00
   

 

 

OPTIONS - Swift Kit & Sleeper Kit

 

Optional Flame Arrestors with adaptors

150.00

Optional Ignition Flywheel Lightening         

95.00

Optional Pump Blue Printing

210.00

Worx Ride Plate 

180.00

Worx Scoop Grate 

190.00

SE Racing Drop Nozzle Kit   

498.00

UMI Billet Throttle with cable adaptor                           

72.00

UMI 4’ Handlebars          

45.50

UMI Steering Plate   

39.00

UMI Handlepole spring tensioner

15.00

 

 

 

 

 

 

Hammer 1 Kit (92 octane)

 

Factory Pipe Products Dry Pipe

795.00

Cylinder porting & decking

360.00

Exhaust manifold matching

20.00

Cylinder head modification          

90.00

Inlet manifold modification           

20.00

Carb “true” boring and jetting)

239.00

Flame Arrestors with adaptors

150.00

Cooling upgrade

20.00

Skat Trak 14/19 Swirl Impeller

298.00
Exit Nozzle Taper Boring 55.00

Worx Ride Plate 

180.00

 

 

OPTIONS – Hammer 1 Kit

 

Optional Ignition Flywheel Lightening            

95.00

Optional Pump Blue Printing

210.00

Worx Scoop Grate 

150.00

SE Racing Drop Nozzle Kit    

498.00

Cylinder Boring

80.00

Wiseco 82.5-82.9mm”Race” Pistons (2)         

236.00

UMI Billet Throttle with cable adaptor                              

72.00

UMI 4’ Handlebars           

45.50

UMI Steering Plate   

39.00

UMI Handlepole spring tensioner

15.00

 

 

 

 

 

 

Superstock  Kit (105+ octane)  

 

Factory Pipe Products Dry Pipe  

795.00

Cylinder porting & decking

360.00

Exhaust manifold matching

20.00

Cylinder Boring

90.00

Wiseco 82.5-82.9mm Pistons (2)         

298.00

R&D Girdle & Head kit

278.00

48mm Novi Carbs

949.00

R&D Inlet Down-draft Manifold & M-16 Reeds                                 

667.00

Flame Arrestor Pods (for Novi 48s)           

98.00

Optional Ignition Flywheel Lightening           

95.00

Advent Ignition          

475.00

Cooling upgrade

20.00

Crankshaft Truing and Welding          

130.00

 

 

Worx Ride Plate

180.00

Worx Scoop Grate

150.00

Skat Trak C-75 12 Vane Pump (exchange)    

950.00

SE Racing Drop Nozzle Kit     

498.00

UMI Billet Throttle with cable adaptor                          

72.00

UMI 4’ Handlebars            

45.50

UMI Steering Plate    

39.00

UMI Handlepole spring tensioner

15.00

 

 
Misc. Labor
 

Cylinder boring, sizing, & chamfer          

90.00

Crankshaft Rebuild w/ Truing and Welding (C4 bearings)         

590.0.00

Center Crank Flywheel Flats (2)        

128.00

Engine teardown and Re-assembly & Pressure Test 

450.00

 

 

 

 

ORDER INFORMATION: SEND ALL PARTS REQUIRED FOR MODIFICATION VIA UPS TO:

GROUP K     4597 CALLE DEL MEDIA FORT MOHAVE, AZ. 86426      928-763-7600

GETTING THE WORK DONE - Most customers send GROUP K the parts needed for modification via UPS, and then do the engine assembly work themselves.  We also do complete engine and pump assemblies for customers who want a finished unit ready for installation.  The new 150-lb. UPS weight limit makes engine shipping practical and affordable.

All orders prepaid with a cashiers check or money order will be returned freight free via ups ground service anywhere in the continental United States.  All other orders will be billed to a visa/master card or sent freight collect cod cashiers check (ups no long accepts cash for cods).   If you would like to pay additional for 3 day, 2 day, or 1 day return shipment, please specify your preference in a cover letter with your parts.  Be sure to include your return address and day phone information in case we have any questions regarding your order.