Rekluse problem(stalling) KTM EXC-F 250 -07


Have problem after I installed Z-start PRO om my KTM EXC-F 250 –07. Sometimes it stalls when I let the throttle down suddenly on second and third gear. It even stalls when I hit trottle on first gear from standing still. I have the medium spring and have tried both 30 and 27 balls and the idle is set to 1800-2000 RPM. It engage just above idle. I am using ordinary racing synthetic oil 10W-40(JASO T903 MA). I even think it´s more difficult to start the engine after I installed the rekluse. I have to run at least 8-10 cycles before it starts(electric starter,neutral gear).

Any solution for my problems ?


The Z-Pro seems to drag more than the standard Z-Start. Try 27 balls with the L5 spring. This should engage at a little higher RPM and a bit more abruptly.

I'm assuming you have set the proper clearance.

Thanks Ud_Luz for your answer!

I have used the L6 spring and if I want higher engagement I must use the M3 spring. See:

I must check the real distance and not use the "no go gauges"

This is the answer I got from Rekluse Tech services:

"Sorry for all the issues with our product Hans. These bike in particular are very tough to set the jetting in the right range, if you are confident that your jetting is correct then I would start by pulling your clutch cover off and checking your install gap with an actual set of feeler gauges (don’t use the no go gauges that came in the kit it will not give you a definite measurement). The ideal gap is between .030 - .040, if the gap is in spec then the next thing to check is the center clutch nut and make sure that it is not too tight. If it is too tight it might be causing the clutch to cough out. If any of these are not the case pull out your clutch pack and make sure that your steel drive plates are sliding up and down on the center clutch freely. We have ran into this before where the inner diameter of the steel drive plates are too narrow and are hanging up on the center clutch when trying to disengage. I hope this will fix your problem if not then shoot us another e-mail and we will do our best to try and make it work."


I assumed it was the xcf versus the sxf, the springs are numbered differently. I have a Pro in an 07 525 and have had a few minor issues too. It tends to drag MUCH more than the old Z-Start and I've noticed this in a few other bikes. While I've never 100% resolved the issue, the stiffest spring with all balls seems to be the best setup. I've also set the idle a touch higher to reduce stalling.

My unit tunes exactly the same as yours and I used M3 with 27 balls. I'm guessing the 525 would tend to be a touch harder to stall due to the greater rotation mass versus the 250. Try M3 with 24 balls if you're an aggressive rider and M3 using 27 with a little higher idle if you're a trail rider. Don't forget if you us M3 with 24 balls the engagement is a bit smoother and some riders tend to slip the clutch too much on the trails.

I checked the install gap this evening and I measured .044", so I did go for the adjustment plate (,060+,030+6 x ,040) instead of 8 x ,040. After that I measured ,033 install gap :ride:

But it will stall anyway in first gear so I think more that I have jetting problem than a clutch problem. The question is if it wants lean or richer fuel mixture on idle ?


Edited by HEDVIN

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