Installed new clutch into 98 civic ex sohc... Stock tranny stage 2 mitsuto manufacturer... When from start motor shakes when engaging... Used stock flywheel didn't replace it... What could be causing the shake in first gear a little in second... Could it be flywheel is bad could that be causing the shaking in first gear

 

Could be the flywheel surface. Could be the subpar quality dollar store clutch kit.

 

 

Clutch chatter from either aggressive clutch material, or a combination of that and a non-machined flywheel surface.

 

It just MIGHT be that shitty clutch you're using.

For what reason did you upgrade the clutch?

 

If you don't have any major power mods, a stage 1 is plenty (our OEM clutch is a stage one Exedy-Daiken clutch - compared to other makes of cars, the D16 have a pretty sporty clutch stock.) If the car shakes and goes away after it engages, that is called clutch chatter and you can adjust your clutch pedal to help a little bit. However, changing a clutch without resurfacing your flywheel is like putting on new brake pads on an old rotor, you aren't getting full contact. Ideally its best to take it apart asap and resurface the flywheel. If you're too lazy, find a steep hill and burn your clutch on it for about 5 or 6 seconds. Rev to about 3500 and let the clutch slip till you smell it. Its a hackjob but its like fast bedding in brakes, and will help for the time being. As you continue to drive, it should get better in time.