the cams measure lift and duration basically the same, (yes i measured them). however the trail is slightly advanced for low rpm re pin location. there are other small minor differences but nothing i saw that was noteworthy. and i did try them all.
I have a 143, cam, pcx injector, etc. decatted exhaust etc, all this was documented on here. I also have an adjustable cam gear and tried them 2 degrees more advanced, and then 2 and 4 retarded. didnt make much difference in maintaining top speed. stroke is the same, cyls actually will swap right over. I even tried a 125 high compression piston. tb cam, etc. Im 99% sure its the ecm, and like said have one on the way.
This is the cam, the 143 cyl (i know it says 124 but its a sleeved stocker). and the yuminashi 238 cam. I can
maintain 55 pretty well flatland, and on long flat runs touch 58-60. and im 205-210 lbs. So, it helped for sure some. the midrange and overall acceleration is
vastly improved though.
these are the trail, grom and TB cam side by side.
I used my dial gauge and degree wheel in my mini lathe to compare them. TB cam was def better for high rpm. the 238 yuminashi cam is better from down low until about 9k. Thats why i went that way, Im not looking for an 11k screamer.
more importantly, i can maintain speed uphill. I know.. a big ask. lol.
But my final mechanical setup is the yuminashi 143 cyl w adjustable gear, the 238 cam, eife set to 21mV, pcx injector and modified exhaust. Over 1200 miles so far on that setup no hiccups. If the ecm works, then i should be good to 60-65 minimally. If not, then i'm going to try a separate stand alone timing controller
also, as aside note the grom heads/cyls WILL swap on w no modifications. ( i had a bunch of stuff leftover from my OG grom, then 2t swapped it later
)