1978 70hp starter won't turn flywheel

[bentcpaw]

I have a newly re-built starter, new battery, new solenoid and battery cables.

I've taken the starter back to the re-build shop and they can't find anything wrong with it.

80% or more the motor turns over easily, starts and runs good.

Some starts, the starter will engage the flywheel and strain to turn it very slowly or not at all.

If I try to turn the flywheel by hand or use a pull chord on the flywheel it is very difficult to turn or not at all.

Eventually, after a dozen attempts with engaging the starter, it will begin to slowly turnover and start as normal.

Could there be pressure build-up in the cylinders that isn't releasing?

Any help would be appreciated.

 

[jimg984]

Re: 1978 70hp starter won't turn flywheel

sounds like the new battery dont have enough cranking amps (2 small)
or its a deep cycle battery, they dont like the rapid draw for starting.
dirty cable connection, bad cable

 

[bentcpaw]

Re: 1978 70hp starter won't turn flywheel

I will check the connections and cables again.

I'm using an Exide Nautilus 1000. That should be plenty of battery.

 

[tashasdaddy]

Re: 1978 70hp starter won't turn flywheel

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

 

[JB]

Re: 1978 70hp starter won't turn flywheel

"If I try to turn the flywheel by hand or use a pull chord on the flywheel it is very difficult to turn or not at all."

You may have a mechanical problem, such as a hydrolock from fuel or water getting into the cylinders, Paw.

Pull the plugs and spin her over. Any fluids being spit out the plug holes? Still stiff? Let us know.

 

[mikesea]

Re: 1978 70hp starter won't turn flywheel

Check your
ground and positive cables,often they can have the insulation crack allowing the wire to become corroded,that will cause insufficent amperage draw.As tashasdaddy mentioned,you can use a good reliable jumper cable to substitute for engine cables.Also the wire from starter to solonoid can also have amp loss for same reason.

 

[bentcpaw]

Re: 1978 70hp starter won't turn flywheel

Can someone tell me what gauge wire runs from the starter to the solenoid?