Adjustable CDI for CN250 How to?

Posts: 5

Dear CN250 drivers,

I have installed an adjustable CDI unit and am experiencing idle trouble and slight misfire... I have a CN250 CDI unit which is yellow and has a single adjustment.

Can any of you give me some tips on tuning this type of unit?

Thanx Very Happy

Posts: 4286

if its the same unit I have, I have one on my cn250 and have found that turning the small dip screw to the left makes it start and run better than all the way to the right.

check the pins in the connector of the cdi plug, sometimes they push out as you plug it in

Posts: 5

This is my unit: (don't take into account the GY6 text it is only the image location)

Posts: 4286

that looks like the one I have.

Posts: 148

I have that one too. Turning it counter clockwise will advance the timing and clockwise will retard the timing. I advanced mine all the way counter clockwise. It only advances 4 degrees. But mine ran fine without any other adjustments.

Posts: 705

Out of curiousity, what does that CDI do for you (in a seat of the pants sort of way)?

Posts: 148

It controls the ignition firing and rpm range. It can limit your RPMs and it controls when the engine produces the spark. So with an adjustable one you can make the engine spark sooner and you can go from 9,000 rpms to 11,000 rpms.

Posts: 705

Posts: 296

My 150 misses after I installed a cdi unit is there an adjustment the the 150?

Greg

Posts: 4286

there is no adjustable one for the 150. I did not feel any seat of the pants feel with my cdi. I still need to play with it to get it set right