Lost low end power switching to 25:1 mix.

[scarabIII]

New builder here switched fuel mixture to 25:1 using 89 octane and seems like my low end went to ****. I switched the needle in the carb to the top slot helped some but still a lot of 4 stroking at low throttle. Will jets help with low and mid range power? motor not grabing to start while peddling does that mean clutch needs tightened up a bit? How do you know how tight to make it?

Thanks
Bob

 

[leo]

hi bob, and welcome.
sounds like you may need to let out a little slack on your cable.
as long as your clutch releases and catches properly, it should be fine.
i have mine setup to disengage the clutch very near the "all the way out" side.
that way, you don't have to pull the handle all the way back to the handlebar to get it to disengage.

 

[mogollonmonster]

Clutch adjustment:
http://motorbicycling.com/showthread.php?t=8392

I've got mine as tight as possible to stop the slip and whine, but my poor motor has to move 330lbs around, between me the bike the trailer and my crap. I also run about 32:1 because of it, and at nearly 3000 miles, my jug looks pretty good. Can't speak much on jetting other than when you change oil-gas ratio, air-fuel is affected as well. Less oil means easier movement, means you run a bit richer, sometimes...