Motor stopped, now wont crank

[danman.]

Re: Motor stopped, now wont crank

will the box come off if its siezed? or will it be a pain?

also would it have done damage to the engine?

thanks

 

[Bt Doctur]

Re: Motor stopped, now wont crank

will the box come off if its siezed? or will it be a pain?
If you mean the complete outdrive, yes

 

[Don S]

Re: Motor stopped, now wont crank

Try removing it and find out. You will have to leave the computer in order to do this.

 

[JustJason]

Re: Motor stopped, now wont crank

So have you or have you not tried to spin it by hand???

most ECU's cut out around 9.5 VDC

 

[erikgreen]

Re: Motor stopped, now wont crank

Try removing it and find out. You will have to leave the computer in order to do this.

Son of a... so THATS what I've been doing wrong

Sorry, don't mean to threadjack...

 

[John_S]

Re: Motor stopped, now wont crank

You might consider finding a new mechanic, if this is the same one that gave it a good bill of health. It is a basic thing to check drive oil for metalic shavings and then refill. For him to tell you the prior owner was at fault because it was low on oil, is a cop out. He should have checked, thats part of the eval you were paying for.

If the drive is stuck on, corrosion on input shaft, etc, there could be other problems. Bellows leaking, u-joint/shift rusting, bad seals and bearings. If he is not experienced in Merc i/o drives, take it to someone that is.

 

[dcg9381]

Re: Motor stopped, now wont crank

So have you or have you not tried to spin it by hand???

most ECU's cut out around 9.5 VDC

Thats what I'd try also. Pull the plugs, put a wrench on the harmonic balancer bolt and turn.. It should turn freely.

 

[danman.]

Re: Motor stopped, now wont crank

Hi Guys,

just an update.

i managed to pull out the gearbox and the top box is definitely seized.

on the up side, the motor started first go and sounds like its running well.

does anybody know how much oil the OMC cobra sterndrives take??

i dont think the guy i bought it off had enough oil in it.

thanks

Dan.

 

[Fishermark]

Re: Motor stopped, now wont crank

Your original post stated you bought a boat with a Mercruiser engine - now you're asking about OMC Cobra outdrives.... what do you actually have?

 

[danman.]

Re: Motor stopped, now wont crank

Well the motor is a mercruiser 4.3lt vortx 92 model. And the sterndive is a OMC cobra. bit of a weird combination i have been told.

Dan.

 

[G1K]

Re: Motor stopped, now wont crank

maybe it's time for some pics?

Ryan

 

[Don S]

Re: Motor stopped, now wont crank

Well the motor is a mercruiser 4.3lt vortx 92 model. And the sterndive is a OMC cobra. bit of a weird combination i have been told.

Dan.

Where I'm from, that is pretty much known as a junkyard dog. It's pieces and parts put together from two completely different marine manufacturers.
The engine blocks may be the same, but everything else is just "FORD compared to CHEVY" different.

 

[danman.]

Re: Motor stopped, now wont crank

So would anyone know how much oil these boxes take?
it only looked as if there was about 800ml in there at most.

thanks

dan.

 

[Lou C]

Re: Motor stopped, now wont crank

So would anyone know how much oil these boxes take?
it only looked as if there was about 800ml in there at most.

thanks

dan.

The standard Cobra takes 64 Oz to fill, so you need 3 qts since you can never get all the oil out of the container using the gear oil pumps. The official OMC way of changing the oil is different from the Merc way (pump from bottom most hole for Merc) . For OMC you remove the dipstick in the top cover and put it in the hole but do not thread in. Then drain from the bottom most hole on the 'bullet' of the lower unit. After it drains, remove the fill plug which is just below the joint between the upper and lower units on the upper foward edge of the lower unit. Replace the drain plug in the bullet. Then screw the gear oil pump into the fill plug opening and SLOWLY pump in oil till it reads full on the dipstick which is resting in the top cover hole, the level should be between the marks on the stick and it should take 64 oz like I said. Then screw in the dipstick, and quickly remove the pump from the fill hole and replace the fill plug. You should use new gaskets on these BTW. The reason for doing it this way is to avoid an air bubble which could result in an underfilled drive. I let it sit for a while and re-check the level with the dipstick, sometimes you need to add a little thru the dip stick hole to get it right after running it. I have done it this way for 6 seasons and never had a problem, just followed the OMC manual.

 

[Don S]

Re: Motor stopped, now wont crank

It should take around 64 oz. (~1892ml)
You have less than half. Probably was filled improperly. It's killed more than one Cobra.

 

[JustJason]

Re: Motor stopped, now wont crank

You should post pictures.... but most cobras are about 2 qts i believe. If it's a king it may be closer to 3.

 

[BAYLINER185]

Re: Motor stopped, now wont crank

Dan
My guess is if the drive seized up due to no oil and it shut the motor down, stalls it out I dont think the motor would be damaged. Think of it like a stick shift car. If you pop the clutch and stall the motor normally nothing happens to the engine.

So I think you need to do what these guys say and pull off the out drive and then try to start the engine. My bet is the engine will start and run fine but it does soound like the drive needs work if theres as much steal comming out and not oil

 

[danman.]

Re: Motor stopped, now wont crank

Thanks for the comments everyone.

yeah as i said earlier i have pulled off the sterndrive and the motor is running well, so as you said the motor has just simply stalled under load.

question i have now is, will the bottom gearbox be ok if i give it a good clean? alot of metal shavings have gone through the bottom box, is it worth cleaning out? or will it be impossible to get all the shavings out?

the bottom box seems to spin freely and shift fine, but will there be any long term damage to bearings/gears/gaskets?

Thanks

Dan.

 

[sarantis]

Re: Motor stopped, now wont crank

I ve experienced the same situation when a mechanic was trying to find out why my engine's problem at WOT.No problem at all with the motor(except the problem i had allready had.I would advise you not to open the lower unit without serious reason.Flush it many times with a soft solvent like gas toghether with compressed air.Take out the impeller so that you can freely rotate the shaft by hand.Work it some times.Each time notice the magnet of drain's screw if it gathers metal shavings any more.Disassembling an old lower unit is a litlle dangerous to make damage.

 

[Don S]

Re: Motor stopped, now wont crank

question i have now is, will the bottom gearbox be ok if i give it a good clean? alot of metal shavings have gone through the bottom box, is it worth cleaning out? or will it be impossible to get all the shavings out?

All that metal floating around in the oil almost always destroys the bearings and usually the contact surface on the gears. They have a flame hardended surface, when that surface gets damaged the gears go very quickly.
Take it apart and look. If the gear contact areas are perfectly smooth they will be fine. But I doubt that will be the case if it was full of metal. Look at the bearing races, if they are all bumpy (for a lack of a better word) you can bet the gears are too.