slow starter

[pa. jet]

thanks in advance for input. upgraded from 50 merc to 90 johnson. when cranking motor barely turns first rev. then spins fine.battery is good. cables are clean and mesure 3/8 od. i think # 6 wire.to thin? motor is a rebuild with 3 hours could it still be tight? thanks again

 

[ezeke]

Re: slow starter

Find the source of the resistance. It will be hot after cranking. Check the cables for corrosion, besides heat, you can feel it when you bend the wire, it gets crunchy. Clean all the grounds and connections at the engine.

#6 battery cables are not up to speed. That's more like what you use in a very short run, like in a car.

 

[tashasdaddy]

Re: slow starter

90% of starter problems are bad connections. remove and clean both ends of the battery cables, so that they are shiney, also the cable from the solenoid to starter. check for nicks in the cables. and make sure the connectors are on the wire good. the cable tend to corrode from the inside out, if nicked, corroded wires, and connections, heat up and cause resistance to the follow of electricity, thus the starter doesn't get enough. you can also take jumper cable pos battery post to large post on starter. with a good connection, the engine should spin. then if the starter is good clean everything and retest. then trouble shoot solenoid. starters can be rebuit at a starter/alternator shop, much cheaper than a new one.

also have the battery load tested at the auto parts store, free, i've had new batteries go bad

 

[HighTrim]

Re: slow starter

You may want to voltage drop test it, both from the battery to the solenoid, and the solenoid to the starter. You will need a DVM for this. A voltage drop test is an effective way to find excessive resistance in high amperage circuits. If a connection is good, you should find little or no voltage drop and see less than 0.4 volts for most connections, and ideally less than 0.1 volts. But if you find more than a few tenths of a voltage drop across a connection, it indicates excessive resistance and a need for cleaning or repair as stated by Ezeke and Tash.

Cranking problems can be caused by undersized replacement cables. A wire's ability to pass current depends on the gauge size of the wire. The fatter the wire, the more current it can safely handle. Some cheap replacement battery cables use smaller gauge wire, which may be camouflaged with thicker insulation to make it appear to be the same size as the original cable. But the cable doesn't have the capacity to handle the current.