does anyone know what this primary weight number means

[sunbather1969]

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its a 07 m1000 4 weight primary and numbers on weights are 710/72 are these 72 and are these stock. thanks

 

[sledstew]

yes 72 gram weights

 

[Idcatman1]

0646-710 is the part number. For some reason Cat only puts the last three digits on the weights. Lack of room maybe?

 

[sunbather1969]

thanks

hey thanks alot that makes a little sense i was shy on r's and not pulling the track speed i wanted. i hear all kinds of info on track speed and rpm . mine with y/w and 72 in primary rkt sec with 38/34 and r/w spins 7250 and 42 track speed in heavy wa powder. stock except bdx black box intake and jaws can with a 174. (i know bought it that way) im not having any problems it tacks instantly should i do anything.

 

[sledstew]

take out the y/w primary spring (thats a 285 finish) and put in a 310 or 320 finish that will raise your rpm or you can tighten your secondary if you have RKT torsion setup that will also help you out on top rpm.

 

[Eli]

Sounds pretty good. Those engines make good power stock in that 7200-7400 range. I don't think 100-200 rpms are going to make any more power or track speed....as long as your backshift and response are good, it sounds pretty good.

on edit:Just looked at Dynotech, and that engine stock makes the same power from 7000-7300....at 7400 it drops by 3hp. I think you are right on the money with a decent track speed for that length!

 

[Arctic Thunder]

take out the y/w primary spring (thats a 285 finish) and put in a 310 or 320 finish that will raise your rpm or you can tighten your secondary if you have RKT torsion setup that will also help you out on top rpm.

^^^I agree get a 300+ finish rate primary spring it will gain you a some R's.

But you are really close on the RPM's now. But for the cost of a spring it might be worth changing it out.

Thunder