[glenn72pc]

I have an rv 10 with a io540 using good size cable "0" gauge cable concorde
25xc and air tech starter the engine is new 90 hr all solenoids check ok cranks slow is the 25 xc the battery used on most 10 or is it to small

 

[170 driver]

I have had alot of success by adding a heavy ground cable between the engine block and the firewall on several cessnas with big continentals in them. A weak ground can be the cause of alot of slow starting problems.

 

[rvbuilder2002]

Make sure you installed the ground cable between the engine case and the firewall, and that you cleaned the paint off the engine case for a good electrical connection with the cable terminal.

 

[CE196]

small battery

I would'nt have a 540 or 520 powered aircraft with a 25 amp battery. Put a 35 amp gel cell in it! Not sure I would do a four cyl with such a small amp hr batt. Not only do you need it for starting, but for your avionics if the alt. fails.