1988 Alpha One

[IVAZ]

Hello,
I purchased a boat over the weekend with a 1988 mercruiser 4.3 and a Alpha one drive. I test drove it with the guy I bought it from and took it home. When I was flushing the engine I noticed no water comes out of the center of the propeller. Is that normal? When I flush my other boat (1978 merc. 4.1 L6 pre-alpha drive) most of the water exits thru the center of the propeller. Are these drives just different or does something need attention?
On another note, what things should be inspected on a new to-you boat?
Thanks.

 

[ziggy]

Re: 1988 Alpha One

if no water exits from the prop. i'd think some inspections may be necessary...

this is a 1 drive. but think your alpha1 should look similar. water exits thru the prop, out the pee hole, and out the gimble housing right up close to the transom.

since the boats new to you, and you don't have water exiting the prop. ya should go look at and replace the water pump impeller... when ya get a new boat. i think it's probably some of the first maintenance ya should do.. overheats are real bad for your engine. these impellers are not to stout either... it don't take much to ruin them..

 

[IVAZ]

Re: 1988 Alpha One

Can the exhaust system be clogged and the engine still run well? Since the boat is new to me I dont really know what to expect out of it but it has way more bottom and top end compared to the 4.1 i6.
What should I check?

 

[ziggy]

Re: 1988 Alpha One

Can the exhaust system be clogged and the engine still run well?

i wouldn't think so...

What should I check?

the impeller...

if it failed. bits and pieces will flow towards the engine. possibly blocking cooling water flow. they can be trapped at the t-stat or worse case, get past that and get into you cooling passages in the block if your unlucky. 'if' it had an overheat (and no water flow out the prop could indicate this via no vanes left on the impeller) . all rubber parts are suspect. waterpump housing, impeller, waterpocket cover, flappers (which will melt off and possibly clogged the exhust flow, guide tube for water pipe between the upper and the lower. might be more that i can't remember too. ya really don't want an overheat and the impeller is the first place to look.... you should have water exiting the prop.. i believe i'd just replaced my impeller in my drive prior to my pic. so my flow is as good as i can get..

so did it run hot?
140* tstat operates between 140-160, 160 tstat operates between 160-180... basicly, whatever yer tstat says on it + 20* to full open..

it has way more bottom and top end compared to the 4.1 i6.

perhaps because they're rated at more hp? might depend on the pitch prop too. one things for sure. mine's a L6, yours is v6 and obviously not the same animals... but our drives are very simialar.. not much difference between a 1 drvie and an alpha1..

a note. it takes about a min. or a little longer for a alpha1 type impeller to go from new to total distruction if it's operated w/o water to the pump..

edit, a pinched water hose between the drive and the gimble housing. would cause no or less flow too...

 

[IVAZ]

Re: 1988 Alpha One

thanks for your reply.
No the engine did not run hot. Temp gauge read 140, a little above that when idling. I only seen it run twice. Once when I bought it an another time yesterday. I did run it about three hours yesterday with no issues. Temps would rise above 140 when idling for five minutes or more but would drop after taking off again. Is this consistent with a bad impeller?

 

[chiefalen]

Re: 1988 Alpha One

No water came out the bypass holes near the transom at all when you ran it on the muffs?

No water at all Came out the transom at all??

 

[IVAZ]

Re: 1988 Alpha One

chief,
Water was coming out of the two holes with the anodes obove them. There was not really any flow coming from the propeller.

 

[bigbob_FTW]

Re: 1988 Alpha One

this is normal. the water will come out the idle relief holes while on the muffs. it will come out the prop on the water at speed.

 

[IVAZ]

Re: 1988 Alpha One

so on the muffs its ok to only have it come out at the holes at the transom.
Thanks bigbob.

 

[bigbob_FTW]

Re: 1988 Alpha One

That's all mine has ever done. No harm at all.

 

[Bondo]

Re: 1988 Alpha One

Ayuh,... Unless that motor's been run Without Water flow...
Then the exhaust flappers might been Burnt up,+ fallin into the exhaust cavity,...
Like this 1,...

 

[IVAZ]

Re: 1988 Alpha One

bond-o,
Are you saying I should have water coming out at the propeller at idle? Im not real clear on what you mean.
Thanks.

 

[Bondo]

Re: 1988 Alpha One

Ayuh,...

There should be Some water thru the prop,... It's a Straight Shot...

If you're getting None,... I'd look deeper to see Why...

 

[ziggy]

Re: 1988 Alpha One

fwiw, here's a 1 season (april-oct) old impeller. exact same as the one in your alpha1. it was not run dry, just used. est. usage is 100hr + or - 25 i suppose. i don't have a hour meter..

got a nice curl to it. it's lost some of it's resilience...

cracks like these appearing on all blades... while some may still call this serviceable. i don't and still think you should go look at yours. just kinda the first thing to do after ya get a i/o. inspect the impeller + inspect the bellows, ujoints and gimble brg. to make sure ya don't get hosed right off the get go...

the water flow out my prop decreased over time from early spring when it was new, to after the end of the season when it had less flow out the prop hub. but still had some...

 

[IVAZ]

Re: 1988 Alpha One

I will change the impeller before running it again.
BTW those are good quality pics ziggy.

 

[dgopetactical]

Re: 1988 Alpha One

I have a 87 alpha one (5.7) with the same issue and it has done this for the 3 years I have had it. No water comes out the prop other than a drop or 2 (spit)pushed out with the exhaust when on the muffs,I do get plenty of water comming out the pee holes on th bottom of the drive and the 2 "exhaust pipes/bypass holes" between the drive and transom.. I have changed the impeller every year and replace the manifolds and t-stat housing last year and im sure nothing restricting flow in the drive and I have no evidence that anything is restricting my cooling system. I have ask merc techs in Md and Pa about the issue to make sure I was not missing something and not one gave me a hint to be concerned when I explained this.

They only time I had water come out of the prop other than some spit is when on the muffs was when I was at a marina in maryland and flushed my motor on the trailer, they had outragous water pressure.

I would do the regular cooling system maitenance..replace impeller, pull the drive and check for restrictions and inspect your manifolds, make sure your boat runs at the recomended temp. etc. Once you have done this and you are sure your cooling system checks out good I personally would not be concerned.
Denny

 

[roks84]

Re: 1988 Alpha One

The only time you will get water out the prop exhaust is when th thermostat is open. While running off the muffs the entering water temperature is between 55 to 65 degrees and if you have the water on full your boat will not get hot enough to open the stat, especially with having no load on the propeller. If there were an issue with the water pumps it would show up while running in the water. If you want to check it, you turn down the water flow and have the boat at idle. What I usually do is reduce the flow so the water is not coming out from the muffs. The boat will heat up now. Most boats stats are 160 degree or a little less. When the stat opens you will see water come out. I do this when I winterize the boat to get all the antifreeze through the engines cooling system and outdrive. Remember to keep an eye on the temperature gage as to not overheat the engine.

 

[IVAZ]

Re: 1988 Alpha One

The only time you will get water out the prop exhaust is when th thermostat is open. While running off the muffs the entering water temperature is between 55 to 65 degrees and if you have the water on full your boat will not get hot enough to open the stat, especially with having no load on the propeller. If there were an issue with the water pumps it would show up while running in the water. If you want to check it, you turn down the water flow and have the boat at idle. What I usually do is reduce the flow so the water is not coming out from the muffs. The boat will heat up now. Most boats stats are 160 degree or a little less. When the stat opens you will see water come out. I do this when I winterize the boat to get all the antifreeze through the engines cooling system and outdrive. Remember to keep an eye on the temperature gage as to not overheat the engine.

Welcome to iboats.
This is kind of an old post, the issues have been resolved. I appreciate your reply. In the future it?s best to resist the urge to reply to old threads. If you have something useful to contribute you should start your own thread. Everybody here enjoys learning new things.

 

[Bigdave196]

Re: 1988 Alpha One

Please tell me that you are lowering your outdrive when your running your Alpha1. U-joints are seriously stressed when you have your outdrive in the "Trailer" position. That is also why little to no water flows out of the Prop if your running muffs. I made that mistake this last early spring when I was breaking in my new motor, ended up replacing the U-joints again because I put about 5 hours on the motor with the muffs on and the motor in the trailer position. Appearently it kills the life span of the U-joints when you do that.

If you are curious to see if you have an exaust flapper stuck in the ehaust system here is an easy self learmed way to check. Run the motor and you should be able to place your hand on the top part of the exaust manifold where the elbow is just before it goes into the rubber pipe that is circle clamped to the "Y" pipe. if one side is noticibly warmer than the other then most likely your exaust flapper is blocking that sides exaust system. You can also remove the rubber hose that comes from the back of the boat that connects the exaust to the outdrive. it kinda looks like a hose for a washing machine drain hose. Look up with a flash light and see if you can see anything. If you still think that there is an issue, go to any auto parts store and get a good exaust manifold gasket set, and pull your manifilds. The Flappers should be sitting a few inches down the Y pipe. They should be sitting right there, if not then its time to start looking for them and get new ones, no flappers can mean a huge repair bill if water gets up in there.

 

[Bigdave196]

Re: 1988 Alpha One

I have also found out the best way to keep certain problems from hiding until your in the water is run the boat like your in the water.

I dont use muffs anymore because if you have a weak or totally failed water pump, you wont know about it until your overheating at the lake. Muffs force water into the system as to when your sittng in the water the water pump in the outdrive pumps it into the system. Bad waterpump in the outdrive means very little water gets pumped to the motor, then your having alkinds of issues.

I went to the local hardware store and got a 33 Gallon trash can and used a razor knife to trim it to size. I lower my outdrive into the can, and turn on the hose full blast. this keeps fresh water going into the can and lets the system run as if it were in the lake.

Just my $.02. Do I get any change back??