Slow crank

[wendellbee]

I have twin inboard ford 460's mated to v-drives. I brought the boat with knowledge that port engine wouldn't turn over at all. the starboard motor cranks and starts with no problem. I was able to turn the port engine by hand so proceeded to repair any thing that needed replacing including a broken dizzy from the PO trying to remove it . Battery is brand new and charged. when cranking, the motor turns very slowly and grinds to a halt after 2-3 rotations, similiar to a dying battery, (the dizzy is not wired yet so it's not firing, just wanted to get the engine to spin. I removed all plugs and motor spins . replaced plugs and removed valve covers to see if everything is moving and it is.. i removed starter and did notice PO ground down some of the housing. I checked with PO and he said starter wouldnt fit until he did that. starter is now in shop being load-tested. my questions:
1 - could i have the wrong starter or is this possibly a wiring issue(bad ground or solenoid)?
2 - even though rockers are moving could i have frozen exhaust valves? i didnt notice any
rust under the valve covers and the oil is clean.

one other thing. the boat sat for 2 years without being started.

thx

 

[Bondo]

Ayuh,.... Welcome Aboard,..... Have ya pulled all the spark plugs to see if the motor will turn over freely,..??

Any rust on any of the spark plugs,..??

 

[wendellbee]

thanks.
yes i did pull the plugs and it did turn over freely. no rust on any of the plugs and no rust visible when i pulled the valve covers. I did notice the large cable on the starter was getting warm, not too hot to touch, yet. .

 

[HT32BSX115]

I have twin inboard ford 460's

OMG!!

Double trouble!

1 - could i have the wrong starter or is this possibly a wiring issue(bad ground or solenoid)?

That is most likely the problem if the engines turn freely with plugs removed. ANY poor connection in either the positive or ground connections to and from the batteries/starters, solenoids can cause slow cranking because each poor /corroded connection increases resistance in the circuit resulting in lower voltage at the load(starter) An otherwise good "looking" solenoid can have internal contacts burned so badly that there'd be a huge voltage drop across it when it's closed and a big (starting) load is being drawn.

You can easily tell if the starter is "bad". Just connect a jumper cable directly to it. If it cranks good, the starter is not likely bad.

If the "large" cable is getting warm, you're drawing a LOT of current. (maybe a bad starter)............. if it's getting "hot" at the crimped connections, those connections are possibly corroded or loose......

2 - even though rockers are moving could i have frozen exhaust valves? i didnt notice any
rust under the valve covers and the oil is clean.

possibly, but that would either result in a rocker that is VERY loose (stuck OPEN valve) or a bent pushrod (depending on where the cam is of course.)

And both would be fairly obvious. grab each rocker and see how loose it gets when you turn the engine................... a stuck valve will have a very loose rocker when the follower is not up on a lobe......

Pictures?



Regards,


Rick

 

[wendellbee]

unfortunately i'm storing my boat 50 miles away from me so i can't provide any pics until friday. a
is that double trouble cause i have fords? LOL

 

[HT32BSX115]

unfortunately i'm storing my boat 50 miles away from me so i can't provide any pics until friday. a
is that double trouble cause i have fords? LOL

Yeah.....expect a lot of "friendly" humor on it. I know I got a little! Now I tend to dish it out!!


You have inboards so you've got most of the battle won! In reality, there's nothing really wrong with the 460. One of the best truck/marine engines ever made! produced from the 60's until the late 90's.............

Problem is the rest of the marine industry didn't support them very well after OMC disappeared.

If yours is an OMC inboard installation, your main challenge will likely be finding manifolds and risers since OMC Cobra manifolds are largely NOT available.

You'll need to obtain manifolds (and possibly risers) from aftermarket sources. For a while, there were adapters that would allow using BBC (454) marine manifolds and risers. I considered them for my previous 460 but I never did find anyone that had them in stock..........

OMC stern drive couplers (for the 460) were NOT available until few years ago when Sierra started sourcing them but they're very expensive, not sure if they are even available anymore and lucky for you, they're probably not used in any marine transmission.

Your transmissions (Hurth, ZF, Velvet etc) probably are still well enough supported by the OEM's for you to get what you might need to keep them running........

Carburetors, distributors and pretty much all the other hard engine parts are completely supportable.


Cheers,


Rick

 

[wendellbee]

thanks for the info Rick. humor never hurts. I'm very well aware of the manifold issue. researched it before i bought this boat/trailer combo. the PO did supply 2 extra manifolds he had, one brand new, the other with very little use (no rust on it). This is my 5th boat and the first one with fords. i prefer chevy's but i'll live with what i've got.