Merc alpha one problems

[MCL]

Hi everybody!

Im having big problems with the alpha one gen one outdrive.The impeller pump broke when we testrunned it at the dock.It might have idled 5-10min without water flowing.Is it possible to burn the outdrive in that time?The engine&manifolds still had water in them.I could barely touch the risers.I had the water level above the water intake but I quess thats not enough.

Second when I put the gear in forward it locks the prop axle so that you cant spin it anticlockwise,but you can spin it clockwise but it makes a sound like it wants to engage a gear.If I put the gear in reverse you can spin the prop axle in either direction and it makes a sound like it tries to engage a gear.The forward gear engages before the engine starts to rev,while the reverse tries to engage only when the gas is at 100% reverse.I checked and the gas/shift mechanism seems to work fine.

Do you think this is a outdrive problems or what?If I replace the whole outdrive with a se drive,can I replace the gen 1 with a gen 2 and is there any improvement?

 

[cr2k]

Re: Merc alpha one problems

Two issues here....

1. No water flow, will not damage the outdrive in this situation. What you may have damaged is the exhaust coupler hoses. No water flow and they will burn up from the inside from the exhaust heat. You need to pull the risers and check the hoses.

2. The shifting issues you are having is either a simple adjustment or possibly a bad short shift cable.

If the impeller is missing any pieces you will need to find them or you will have problems in the future. Most pieces that make it out of the impeller housing get trapped in the heat exchanger (if you have power steering) or in the thermostat and or housing without PS. Either case it is important to find and remove ALL the pieces no matter how small.

 

[jerryjerry05]

Re: Merc alpha one problems

You most defiantly ruined the water pump. The flappers in the exhaust down tubes might have burned up.
The boat must be in the water to check the shifting.J

 

[bigskiohio]

Re: Merc alpha one problems

i agree with the shifting in water as mine shifted fine in drive but on lake i had to adjust my cable.

 

[achris]

Re: Merc alpha one problems

You may have also melted the water pocket cover, situated inside the drive.. Do a search here on water pocket cover. Plenty of threads on that. If you have damaged it, it's a nasty to replace.

What you are hearing with the prop shaft ratcheting in forward gear is normal.

Chris.......

 

[ziggy]

Re: Merc alpha one problems

hope ya didn't melt yer water pocket cover. they're miserable to deal with considering it's only 4 bolts and the cover and a gasket. i found mine bad while flushing impeller bits out of the system from ft. to back. had the lower removed and could see water flowing out the gasket seal. along with impeller pieces.. if you find it damaged. read up on it before you start loosening bolts. cause the bolts will likely break off. then you'll have a whole different problem.

Second when I put the gear in forward it locks the prop axle so that you cant spin it anticlockwise,but you can spin it clockwise but it makes a sound like it wants to engage a gear..

that's normal. the ratcheting is the dog clutch falling off gear as it is rotated the wrong way for engagement.

If I put the gear in reverse you can spin the prop axle in either direction and it makes a sound like it tries to engage a gear.The forward gear engages before the engine starts to rev,while the reverse tries to engage only when the gas is at 100% reverse

that is not normal.

when proper

fwd= prop locks in the ccw direction and ratchets in the cw direction
neutral= the prop freewheels in both directions and makes no sound
rev= prop locks in the cw direction and ratchets in the ccw direction.

something is amiss. ya can recheck your adj. for the lower shift cable. pretty much put the remote at the helm in fwd then measure center to center of the mounting points and it should be 6'' (read the s/m for the exact procedure). from what i've learned here from others, a lower shift cable don't go out of adj. they do however fail and need replacement when they become hard to move.
read this from the adults only sticky at the top of the i/o fourm..
http://forums.iboats.com/showthread.php?p=1930449#post1930449

 

[MCL]

Re: Merc alpha one problems

Hi,thanks for all the help.

The impeller is most definitely gone.I will order a complete impeller kit,a new circulating pump and the water pocket cover.Is thisthe right part?

I will clean all the remaining bits from the drive and run the hose to the engine into a bucket for a while.Im installing a full fresh water kit to it,I already checked the hoses from the risers and they all seemed fine.The engine only idle for 5-10min.What are the flappers in the exhaust tubes?

I hope its just a adjustment problem,I did get it once engaged in reverse but that was with some luck and throttle 100% reverse.So I hope the drive is fine.

 

[ziggy]

Re: Merc alpha one problems

and the water pocket cover.Is thisthe right part?

yep, that's a water pocket cover.
you do understand that if you touch them water cover bolts that are on your drive right now, that they will probably break off? you break just one off and you can commit yourself to a new upper for the repair. over one broke bolt, if you can't get it out.

i have read of people replacing the water pocket cover w/o breaking the bolts, but i've also read about folks that they do break on. i'm one of the ones that has had them break off. and they are extremely hard to extract if they do break off.

be sure that cover is truly damaged prior to replacing that item. this is not a part ya just wanna replace because you can get at it.

oh, did i say that them bolts are made of stainless steel. mounted in cast aluminum and that you don't wanna break them bolts off.... oh, i said that.

be very careful when dealing with the water pocket cover imho...

What are the flappers

they sit in the exhaust pipe and act as a one way valve to let water (and exhaust gases) out of the exhaust system. if water trys to flow backwards, towards the engine. the flappers (exhaust water shutter) mostly seals and prevents water from flowing backwards into the exhaust system.
flappers.. http://www.iboats.com/Mercruiser-Wa...6666975--**********.927138263--view_id.268813
you would order them per the kind of engine you have...

 

[MCL]

Re: Merc alpha one problems

Back again.I have the drive pulled and split.Waterpump was toast as expected.The plastic pipe from the waterpump had melted.The waterpump hadnt suffered any heat damage yet,so its should be good.I tested the water pocket cover and it didnt leak.

But I do have one question.With the waterpump removed there is a lot of play in the driveshaft in the lower housing.Is this normal?

 

[MCL]

Re: Merc alpha one problems

Also the grease on the upper housing drive shaft oil seal looked milky,I suspect it might be leaking a bit of water.Can I just pull these seals and install new ones?

 

[Bt Doctur]

Re: Merc alpha one problems

The play is normal, the gears are cut in such a way to force the driveshaft upwards for the correct clearance (Alpha) ,the older drives used a preload pin to push the driveshaft downwards to set clearance.(MC1, pre Alpha) The lower seal can be replaced with the unit split, the inner one needs the upper unit disassembled.