Group K SXR 850 Big Bore Sleeper Kit

SKItarist750

SKItarist750

Custom Kawi
Location
Lansing, MI
I was reading up on the Group K SXR 850 Big Bore Sleeper Kit. They make it sound like a win-win upgrade, so I was thinking about having that done in the next year or so. Has anyone had this done to their SXR? Is it worth the money??? Group K boasts a big increase in low/mid throttle and +7 mph top speed, all while maintaining stock fuel economy, low RPMs, and engine longevity. Too good to be true???
 
Shonuff

Shonuff

I've got the glow
Site Supporter
Location
Memphis
I got that upgrade and I think this is reasonably good advice:

You can get just as much hit with the following mods to your stock motor:

TBM Lightweight charging flywheel
TBM Pump Cone
FPP Wet Pipe
Skat Trak 9/17
80mm Bored Exit Nozzle

I think these will put you to or surpass where I am with my setup AND MORE IMPORTANTLY, all these things transfer over to a stroker setup later on if you want to add even more. Also, you can financially piece these together over time where my BB850 kit was a $1600 hit on my bank card all at once.
 
Shonuff

Shonuff

I've got the glow
Site Supporter
Location
Memphis
I didn't mention a new head and domes because if you've got a 2005 SX-R, you're probably running pretty close to 170psi still.
 
Martin33

Martin33

LIVE ACTION !
Location
Azle, Texas
I was going to install everything shonuff listed above to start with. I was also wondering about the bore kit, all I really care about is the pump gas issue.. Race gas is a little pricey for how much these things burn.

Daniel
 
D

Don 79 TA

Still Fat....
Location
Madision/Huntsville AL
I can tell you the setup i have on her SXR really kicks some a$$
but i am a fan of race gas, just love that SNAP it can give, i buy about 150 gals/season, so WELL worth it to me
her setup feels VERY strong, easily pulls me up and out of the water with no probs

Impros prop with blowsion trim system and pump work
RAD flywheel
port matched motor (blue printed kommander motor)
RD timing advance
Kommander head with 26cc domes
stock exhaust
3dr hood (light wieght)
VF3 reeds
some other odds and ends

her setup is awesome on fuel mileage too, makes a great tow ski (for when i run out of fuel)

I hope we can change the exhaust next year to the Wet pipe, would like to see that difference

i've thought about going to big bore, but waiting to possibly going to a DASA cylinder.

talk to Steve at Kommander, he has a wealth of Kawi knowledge.
 
GIL

GIL

Power In The Hands Of Few
Location
Cullman AL
Group K is commonly reffered to as Group Kmart for a reason. If u really want to haul azz and have a really hard hit-call Art at Jetworks.
 
Martin33

Martin33

LIVE ACTION !
Location
Azle, Texas
I was reading alot on their site and it seems...well ...they do their homework IMO. I was thinking of sending my motor off to Group K and just let them handle it. I really just want a setup that I dont have to run race gas, and still get the most punch I can low to mid.

Daniel:brap:
 
Shonuff

Shonuff

I've got the glow
Site Supporter
Location
Memphis
Martin33 said:
I was reading alot on their site and it seems...well ...they do their homework IMO. I was thinking of sending my motor off to Group K and just let them handle it. I really just want a setup that I dont have to run race gas, and still get the most punch I can low to mid.

Daniel:brap:
Click to expand...

Race gas is your friend plus is smells great.
 
dbrutherford

dbrutherford

Parts Whore
Location
Fairmont, WV
I used to have a Group K 750. It ran good but didn't have any snap so to speak. It was a small pin but was all mid and top. One thing I did run into was that they recommended certain parts (from their web articles) which I bought and then they called after I sent them the cylinder that I needed other parts. I used 650 electrics and they recommened 750 electrics. Even though I had a jetinetics wheel and Dale's box. This was a 750 SS engine into a 650 SX.

I will say the port work look great and I was impressed with the machining. However I must warn you that Group K tends to stay on the conservative side of things. They are also a machine shop so they don't push aftermarket parts. They want to sell you some machine shop work instead.

Also once I seized the engine twice, they were less than helpful. I didn't have the cash then to buy a Keihin carb from them and they wouldn't help me with jetting with my Mikuni SBN carb. Now what is funny is that they now recommend a 44 SBN for their 650 package when for years they recommended the Keihin. I think they must have been a keihin dealer because they recommende them for Yamahas even! A Yamaha comes with a SBN stock, just stick to one of those and save cash that would have been spent on a manifold.


So I do recommend them, I just probably won't use them again myself. The seizures were just as much my fault as theirs.

And one last note. I don't think a big bore on the stock cylinder is all that smart. I would look to the DASA cylinder of you want to go big bore. Group K is always advising against o-ring heads because they cannot seal as well as a "propperly modified stock head." So why they selling a big bore that removes most of the sealign area of the gasket? Just not a good practice if you ask me. Then again I am not sure wether or not the DASA cylinder moves the cylinder studs farther out from the bore.

if you do go with Group K. Make sure you do everything 100% to a T as to what they say. Otherwise they wojn't be much tech support help and you will be stuck scratching your head and crying over the money lost.
 
wsuwrhr

wsuwrhr

Purveyor of the Biggest Brapp
Location
Alta Loma, working in Upland
DASA uses their own custom head with a normal style bolt pattern.

Brian

dbrutherford said:
And one last note. I don't think a big bore on the stock cylinder is all that smart. I would look to the DASA cylinder of you want to go big bore. Group K is always advising against o-ring heads because they cannot seal as well as a "propperly modified stock head." So why they selling a big bore that removes most of the sealign area of the gasket? Just not a good practice if you ask me. Then again I am not sure wether or not the DASA cylinder moves the cylinder studs farther out from the bore.
Click to expand...
 
dbrutherford

dbrutherford

Parts Whore
Location
Fairmont, WV
Good to know. I figured something like that was necessary. Care to price a top end kit? Say cylinder, head, gaskets, o-rings, circlips, wrist pins, wrist pin bearings, pistons, & rings? What bore sizes are available? If a stock stroke cylinder is purchased, can it later be upgraded with a stroker crank or is a spacer plate or different cylinder necessary? I would eventually like to get one. Pump gas average compression with rec porting and of course... POWER VALVES!

DBR
 
Martin33

Martin33

LIVE ACTION !
Location
Azle, Texas
Wow, ok, I guess there's been some people already down that road. With that in mind I'll prob just stick with the original setup , carbs, bore etc.. Thanks for telling about your experience with group K. Everyone has their own opinion, but when there's 4 or 5 people telling the same story, it's only obvious.

Thanks, Daniel
 
dbrutherford

dbrutherford

Parts Whore
Location
Fairmont, WV
Thereis nothing too terribly wrong with Group K, they sell a nice package. But it is just that, a PACKAGE. You must do everything they say and sell. I just don't get building an engine and not using the stock pipe for it... I just had a bad experience after the sale. Yes it was mostly my fault but I was already out a lot of cash and summer weeks. I just wanted some guidence and never got it. I mean come on, Harry K can't help me jet a carb? Instead he wanted to sell me one of his carbs case in point.

Listen to Korn and Sho, they have both owned SXRs for years now.
 
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