It's not the 60 that I was hoping for, but I was still happy with the results. I'm sure it would hit 60 on a different day or different dyno.

I still want MORE POWER, though!



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After getting the final numbers, the operator was telling me that switching to an FCI would gain me some more power on top. He had one on his shelf so we bolted it on and made a few passes. I am sure there was a little more left in it with some small adjustments, but what I saw did not sell me on the $200+ price tag.

I'll stick with my $50 used ESR and a $4 tube of JB stick weld.

Here is the FCI


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your fci test looked like your clutch was starting to slip with the tail whip on the dyno run....

the whip usually suggests that the clutch was finally able to grap at that rpm...

Looks like the FCI did your build stronger where your clutch began breaking loose, or your clutch got up to temp at that point and begun slipping....

Either way, I'd say the you should try the FCI again....


Good luck with your build.

That's some great runs! Where did you dyno at? I hear Mike is gone from LS Powersports.

hmmm.... That makes a lot of sense. I have never seen what a slipping clutch looks like on a dyno. Maybe I will have to give it another try. I do have a new clutch sitting on the bench right now.






My bike was tuned at SandTrax in Tulsa. I am not familiar with the guys at LS Powersports, but on Saturday my friend had his KTM525xc tuned by a guy named Mike. Younger guy with a Blue 04/05 TRX. He did a great job at tuning the KTM.

What does a stock bike make on this dyno?

I asked him that and he said 37ish HP. Can't remember what torque he said.

Thanks for the reference.

Nice ....looks like a runner for sure.

Great power pgreenlaw. Looks healthy and keeps pulling to 9600 RPM.

You said a stock bike makes around 36-37hp on this dyno yes? Seems pretty consistent with most I believe.

I would imagine there is definitely more power in...
- a larger carb...maybe have sredrum bore it out to 43 or 43.5mm
- stroker crank
- bigger cam
- different exhaust

The FCI results definitely surprise me. My personal build loved the FCI and I still use it. The bump on that graph around 8k is exactly what my bike looked like when my clutch was gone.

How many hours are on the clutch and springs? What kind of clutch springs are you using...takes a pretty stiff/long spring to hold almost 60hp...

Not bad. Your almost in the 60 HP club

I just paid to have the carb bored to 42mm!!!! Now I kind of wish I had just splurged and went with the 43.5mm


Probably 50 hours or so on the Tusk HD clutch with their HD springs.

I am believing more and more that my clutch was slipping with what that graph was showing. Maybe I didn't give the FCI the credit it was due....

Here are the graphs overlayed. It did look like the FCI was starting out soft on bottom and may have surpassed the ESR in the top end. I would like some more opinions on this one...

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Strong bike Pat!!!!!!!!! I'd definitely be happy with that. Seems like a lot of good suggestions above also.

Here is the FCI with smoothing turned down to 1:

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congrats on the build man... you might look into the cr500 springs.. they are bi@tch to pull but you wont slip anymore. i never had good luck with the tusk heavy duties..

the ebc cr500 's are 10 bucks off RMATV..

i think i still have set of the regular dark synergys somewhere i will look and see if i do.. you can try them out and see if you like them.. they didnt work for me.

congrats man!! sandtrax is top notch in my book.. those guys did most of my banshee stuff and that thing ran like a bat out of hell!!

later aaron

Thanks for the offer, Aaron. I actually just ordered some CR500 springs. Got a new Tusk sitting on the bench so hoepfully that will be a little better combination.

I also use CR500 springs with the stock clutch mod and my 490 06 holds up pretty well clutch wise.

pat........... very nice. im happy for you to finally get it back together and running strong.

i recommend the cr500 springs as well. i was scared of the clutch pull being to stiff. i was surprised. it is stiffer, but not to where its problem.

the FCI did similar on mine. it and and stock 08 box kept crossing over one another all the way to nearly the top. then the FCI pulled a full
1.5 hp over the 08.

i would bet that tuned out you would cross 60 with the FCI.

Thanks, Steven. I have my new clutch and the springs should be here early next week. Tulsa is a ways away for me so I do not know when I will be back on the rollers next. And after seeing the graph, I am not going to throw the FCI on there without getting it tuned. I will stick with the ESR for now until the next trip...