My CDI hates me

[butre]

I


Thank you for this picture! I am going to invest a few hours if elbow grease to see if I can replicate this!

that's not a completed head, the squish band needs more cutting. it's still at 40mm or so outside to outside in that photo.

it's also a stock head cut down to 5.5cc, so you'll want a colder range plug and colder burning fuel if you were to do it exactly as I did.

the tool I use for cutting a squish band is a fushigi ball on a stick with some sandpaper glued to it. it's a little more idiot proof than cutting it on a lathe and you don't need to have any fancy jigs to do it, just chuck it up in a drill and go to town. plus it was cheap, the aluminum round stock I used for a shank was scrap from another project and the fushigi was $1 at goodwill.

you could also use an old piston, but I save those for metal sculptures to sell on etsy.

 

[Bruce Welham]

I'm thinking that the little gear inside the clutch cover (main drive) may be loose, kicking out a bit and hitting the clutch cover. I wouldn't think that the CDI could make noises, at least not like that.

Probably the bolt coming loose that holds that little gear on. I had one come loose and it went right through the cover!!

 

[skyash]

I milled 1 mm off the stock head and got little power increase looked just like the pick after a week it blows gaskets after gasket. So no gaskets just silicone. And working fine for a week then same blow out silicone. My bike went really good and with the 1 mm off not much difference like 1 percent but it all counts.

 

[mrbg]

My squeek is from no grease on bust bar, only cdi related stuff would be rough running and vibration, connections loose somewhere. My two bikes both with so called balanced motor are settled and run well a 40t sprocket and CNC clamshell. That is good for cruisin 25-30,motor isn't.

 

[Tank352]

No more noise. Thought about it after I fixed it. The noise was coming from air going around the head gasket just as the sound when you blow on a piece off grass or plastic to make the scretching sound.