Hello all,
New member here with a restoration project that is starting to get the better of me. I posted this on another forum, but wanted to see if I could gain some info here as well...
First the history...
Back in November of '16, I bought a 05 sportsman 700 twin efi. This would be my first atv and between my untrained eyes and the sellers skill at camoflaging it's many issues, I took it home after paying about twice what I should have. I also made the deal at 7pm, in the dark and had to use a flashlight to check it out...lessons learned...
The next day, I unloaded it and started checking it out and began reading through pages on this and other atv forums.
I could fill a truck bed with all the parts I have replaced and hauled off including all the a-arms, bushings, wheel bearings, front struts, tires, sway bars, ball joints, T-bap sensor harness, exhaust header, rocker cover and breather, air filter, water pump mechanical seal and impeller, oil pump seal, voltage regulator, starter solenoid, battery. I've changed all the oils in the transmission, diffs, and engine (x2), new drive belt and coolant. I even rebuilt the gear selector box on the transmission.
I have a service manual, and all the tools I need to do almost anything I may need to do to this machine. I know how to use the diagnostic function on the machine.
At present, there are no codes. When the battery is charged, the machine starts and runs great! Lots of acceleration and scary fast! No miss firing, knocking, or rattling, (except a little tapping near the flywheel area that I've learned is normal).
The main problem I have left to overcome is a battery drain. If it sits overnight, it won't start in the morning.
I've done the voltage checks and believe it's charging properly, however, the voltage shown on the diagnostic menu differs from what my meter says at the battery...meter showing 14.4, screen showing 13.9...
When I pulled the flywheel and stator, nothing looked burnt or melted...
Speedometer doesn't work, but hall effect sensor cable doesn't appear to be damaged. AWD works properly.
I went so far as to buy a used ECU from same model and year atv on ebay. When I changed it out, the machine wouldn't start. When I put mine back on, it started and ran fine. Seller refunded money but told me it tested fine on his end. I'm prepared to buy a brand new ECU, but I'm into this 12 year old atv for almost 4k now and am getting frustrated.
Can anyone offer suggestions as to what can cause the drain? I've searched many times and most problems of this type on the forums involve a carbureted 700. Not the efi that I have...

One more thing...the old battery was a sealed agm and I replaced it with a new lithium type. Might this have something to do with it?

Sorry for the long post and any insight would be appreciated.

 

I'd check for a parasitic drain. May involve unplugging different items one at a time until you find the voltage thief.See if the last paragraph from Battery Stuff helps. https://www.batterystuff.com/kb/arti...itic-load.html

 

Polaris Tech,
Thanks for the quick response. I did what you said and if I did it right, it has a 3.2 milliamp drain...



I've already disconnected the winch to eliminate it from the lineup. Also, evidently I didn't fix the charging problem when I replaced the voltage regulator. I rode it today for about 20 minutes and it almost killed the battery. I shut it off and went to restart. It turned over slowly and the battery indicator was flashing once it fired up.
BUT...while it's running I can probe the battery terminals and it shows 14.4 volts!
I'm leaning towards ECU, but would like to be more sure before I cough up another $300...

 

Well, it turns out that the brand new battery that I installed came with a dead cell. Because it was so new, the store refunded me the money and after purchasing another new AGM battery, the charging and draining issues all went away.
Thanks for the reply.

 

Like posted on the Battery Stuff site batteries can be bad even if new. I had stacks of them waiting for warranty pickup at the shop that were doa or shortly after installation and couldn't hold a charge. Just because one may show 12+ volts doesn't mean that it's good. Glad you found the problem.