I am having trouble starting my new motor(80miles on it). I can not crank the motor with the battery alone, I need to put a 100A booster on it and it cranks and cranks and cranks and after about 5-10 mins of cranking(with lots a cool downs) it will begin to sputter then finally fire up. I do believe I need a new battery but I wanted to exhaust all other options before hand. I check the leading coil connector and WITH the booster I am only seeing 10.5V and 6.5 without. Is there any reason as to why there is such a drop? The dash volt meter shows around 15.5v with the booster on. Any help would be awesome, I want to drive this thing and have it reliable.

i think, that the power goes from the battery to the fuse block thru the main relay, to the coil. soOOOooo there are a couple connections on the under hood fuse block that can get cleaned up, and then you may wanna check out the main relay too

first off clean all connections at the battery and check all the connections at the fuse box under the hood. after that read this and do it.

VVVV

http://www.aaroncake.net/rx-7/grounding.htm

How would I test the main relay?

two ways, either check the voltage in and out, or click it "on" and check resistance.

Thank you! I am going to try the grounding writeup. Today I replaced the positive battery cable and it helped a bit but I am still having the problem. Also, I had the battery tested and it passed but the guy at the store only tested it at 200 cranking amps, so could the battery still be toast?