Re: 125 elpto prop question
What is your WOT RPM?
If WOT RPM is too much on the low side of the recommended operating range AND motor mounting height is perfected, THEN maybe 26 pitch may be too much.
Before you buy another prop verify that your tune up is also perfected, timing, carb link and synch, etc.
The vented Lazer prop should let the motor 'spool up' and help make a good holeshot, if you have remmoveable 'vent plugs' in the prop take them out and retest holeshot.