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No Raw water flow 5.7 merc w/ alpha 1 gen 1-gctid808534

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  • grey.wilfong
    replied
    Steve in Cal,

    I did have to polish the surfaces where the balls seat and stretch the springs out a little, but other wise, like Ruffy said, just tighten the Lock nut down and be sure everything is moving smoothly and seating properly.

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  • captharv
    replied
    "Chief Alen" post=808751 wrote:
    check #9 #3 #2 ether the tube is cracked , the impeller housing wear plate or the housing itself is fugazied.

    I like to install the complete new housing with impeller.

    Speaking of the impeller it's aftermarket ?

    Reminding everyone this is a alpha 1 gen 1 drive he has, and i actually prefer it to the gen 2.

    [attachment]36229 wrote:
    Alpha-one-lower-gear-case-layout-drawing.jpg[/attachment]
    Look in the diagram where #36 is. This is a cover on the "strainer" for the intake water to the pump above it. When Alpha impellors get dry and disintegrate, the pieces drop down into the compartment inside #36. Take the screw loose and look inside, if there are pieces of rubber inside, that's the problem. Clean it out and try again. The reason I know this is my friend had this happen on his boat. Also run a car speedometer cable thru the part from the pump to the top of the drive.

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  • Ruffryder
    replied
    No adjustment to those check balls,

    Just tighten the lock nuts.

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  • SteveInCal
    replied
    "grey.wilfong" post=811514 wrote:
    Small note on my specific engine and thermostat housing. This specific version appears to be around 1989 or so thermostat housing design number II. It has the two additional hoses that connect to the upper exhaust elbows(presumably for cooling the elbow?) and apparently needs those check ball and for them to be adjusted properly.
    Haven't been on this site in a long time! Good to see the same good folks helping people with problems

    How do you adjust the check balls? I have a 1989 5.0 with A1G1 and a similar setup. My elbows always run hotter than most folks say they should., so maybe my check balls need adjustment?

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  • grey.wilfong
    replied
    Small note on my specific engine and thermostat housing. This specific version appears to be around 1989 or so thermostat housing design number II. It has the two additional hoses that connect to the upper exhaust elbows(presumably for cooling the elbow?) and apparently needs those check ball and for them to be adjusted properly.

    Leave a comment:


  • grey.wilfong
    replied
    OK problem solved! Did a run all day temp guage spot on @ 175.

    Did a run in the lake and got impeller flow but still overheating.Turns out It was the durn check balls. Found a used set as my unit didn't have any, and for grins and giggles popped 'em in and made sure they seated nicely. I'm figuring since mine weren't installed it was allowing too low of a pressure in the thermostat housing and letting too much water go directly to the exhaust elbows causing the overheat. it may have worked fine at higher RPM but I never got that far as it heated up rather quickly.

    Problem solved and I am loving running the ol girl around the lake!

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  • grey.wilfong
    replied
    Bounty, Excellent info! I can infer the rest from the small differences. Thanks a lot!

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  • grey.wilfong
    replied
    Sounds like exactly what I may be looking at! All indications of centering of the shaft is slightly off center but if the blades took a set and pushing against water might be just enough to cause the problem I'm seeing especially at idle "displacement " mode. Intend to put in a whole new kit before my next outing.

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  • 2850Bounty
    replied
    "grey.wilfong" post=808717 wrote:
    Bounty, Nope no debris and thanks for the rundown...for what ever reason i was having trouble picturing the inner chambers of the T stat housing.
    [color]blue wrote:
    This first image was drawn up for a member with an AQ series Volvo Penta with the crankshaft seawater pump.

    The T-stat housing (in the way that it directs seawater) is very similar to what you will have.

    [/color]

    [attachment]36260 wrote:
    Raw water cooling T stat housing explanation.jpg[/attachment]

    [attachment]36259 wrote:
    Raw water cooling T stat housing explanation 2.jpg[/attachment]


    Attached files

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  • Chief_Alen
    replied
    If you had open / apart on a bench both the gen 1 and the gen 2 you would understand why the gen 1 is the superior drive.

    Yes the impeller and housing should be changed out, a complete new oem one.

    Can't seem to get that across to my friends as well as on this forum, trying to save a few dollars by just changing out the impeller.

    Leave a comment:


  • Guest
    Guest replied
    We had an A1Gen1 for a while in our '86 Wellcraft. The Impeller in the raw water pump was problematic. Needed to be replaced regularily. The pump works by having the metal cover over the rubber pump a bit off centered. The water on the intake (wide side) is forced into the housing and pushed out through the narrow side up into the engine thermostat area as the engine turns. The problem is the rubber impeller blades take a set after a while and don't ssring back out when the impeller is approaching the wide side causing leaks and therefore no water to the engine. If you saw an Alpha "Gen II" impeller you would immediately see how much bigger and beefier it is. Our second boat , a '97 2355 is a gen II. Much better.

    For you, I recommend either a new rubber pump or a whole new--pump. And buy a good set of ear muffs. Also, the pros often wont start your engine out of the water. They don't like to gamble on air getting air in around the muffs. I don't know if one can backfit a Gen II into an older boat which had the Gen I. It would be nice if they could! Hope this helps.

    Don

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  • 88fourwinns
    replied
    I think your problem is trying to run it in a barrel. This really does not work with outdrives because due to the design of the transom mount you can't get the water intakes deep enough. Ideally you would want the drive submerged fully so the water will force the air out of the pump. Impellers will not pump against air. Use a set of good fitting muffs or you will just burn up perfectly good impellers.

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  • grey.wilfong
    replied
    Yep thats what I'm trying next.

    Quoted from my post #7: After some sleep on it, I'm thinking that the impeller is having issues priming. Perhaps I need a bit deeper tub. The current one comes up to the Cavitation plate but the drive usually is deeper than that in the water and at the cavitation plate the impeller may not be completely submerged. SOOOOO...either get it on muffs(difficult at my storage location) or take her out to the ramp and see what she does.(Thinking that would be better as it is closer to actual operation and doesn't have the extra PSI you would get from the hose.)Then if I get good flow to all the places I've already checked, I'll either be cooling good or Dig deeper

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  • Chief_Alen
    replied
    Try to submerge the drive past the water pump.

    You may have to dip the boat in a lake or sea.

    Leave a comment:


  • grey.wilfong
    replied
    I replaced #3 it was dry rotted

    #9 is the guide tube that was fine

    #2 the housing itself was in good condition no cracks gouges wear or melting of any sort.

    Upper and lower wear plates in good condition

    I also replaced the slinger (72?)

    Leave a comment:

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