Starting to strip my 2013 4t.. gearbox issues…. Cant select gears, lat month I snapped the quadrant off the gear change shaft.. I repaired that and made a new pivot slide for the change fork as it was really sloppy… gear change was brilliant after… until I dropped the bike onto rocks now I can sometimes select either 1st or 2nd but nothing else… the gear shift drum behind the clutch basket isn’t moving so something is amiss in the gearbox.. started stripping the engine today and first snag is I can’t pull the plastic water pump impellor off its shaft!.. circlip is removed, there’s a little bit of movement between the shaft and the plastic impeller but it’s stuck fast!… tried pulling with all I can whilst gripping with a pair of pliers and it’s not moving… any thoughts?… thought I’d get further than this before I hit a snag!

The water pump impellor should have nothing to do with the head/ cylinder coming off. To be honest I never had to rebuild the 4 stroke beta thank god. We now ride Montesa.

I did wonder that and that was going to be my next question!… I’m just working through the manual in the order it shows atm. 
funnily enough we went the other way.. 4RT to beta 4t!

In answer to my question.. yes the pump does need to come out to lift the barrel as the water pump gear and shaft won’t allow the chain to come out… impeller was just very very tight on the  shaft. Had to keep pulling with wide pliers… not nice but got it off in the end!