Scooterotica

What clip is the X7 running on? Is it running an air filter or not? Hole in the panel or not?

Heat:
Check jetting throughout the rev range, not just main jet.....where is he holding the throttle, what revs is he riding at in 4th?
Re-check TDC first with positive stop, then set timing, then strobe....do NOT trust timing marks.
Check squish gap (As Sean says 1.2-1.5 is best - over 1.7 will cause problems - the closer to 1.2 the better)
Check compression ratio - machine bowl or change cylinder head to low-comp version
Check flywheel and cowl are a tight fit to each other for max air flow
Check ring gap and replace worn rings
Remove any obstructions to cooling efficiencies (splash plate etc)

sean brady scooters wrote:NO NO....to keep the heat down ,you need a tighter squish........

ahh.... didn't realise that. how does that work ?
i had originally had it about 1.3, but it was pinking then too... i shall fit a thinner gasket again...

tried all clip positions on all needles
no filter
no hole in panel
I made the timing marks in the first place, I have rechecked them, and the timing with a strobe; no, i never take any note of the marks statically
it's a new piston, rings etc. ring gap was ~ 0.25mm
I'll check the fan efficiency etc again.
but I think the slide is the thing that'll make the difference, it is probably around or just above ¼ throttle that he is riding...

thanks for the ideas

please read and check this out matey...
http://scooterotica.org/forum/viewtopic.php?f=5&t=9439

sean brady scooters wrote:please read and check this out matey...
http://scooterotica.org/forum/viewtopic.php?f=5&t=9439

ahh thanks. a good read

Fuel/oil percentage?

sideout wrote:Fuel/oil percentage?

that's fine afaik
but will change that for a known good mix if the next steps don't work
thanks.

time to change your signature ??

I've never known an X7 be anything but too weak in the midrange throttle opening on a Muggy. X13 would be better. Change to a 40 slide, reduce idle jet to 50/52, Tighten the Squish, set timing to 18 BTDC, and should be better. If it's a MK1 Muggy then the reaper heads supplied were dire . . . too high compression and the squish area not matching the piston. A properly machined head would pay dividends here. Keep the theoretical compression down to about 9.5 to one.

Good luck.

thanks again.
slide and needle change is next then

byron wrote:time to change your signature ??

Too right! Any suggestions