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gazza2006au
09-11-2018, 08:02 PM
A bit baffled by this one, as you know i have a mid 1980's Mariner 50hp the 3 cylinder model i got it running the other day and put a new impeller in it tonight i grabbed the test drum filled it up got the engine running it was idling a little high so i shut it down it was pumping good water i topped off the drum with water made throttle link adjustments than started her up and she wouldn't pump water

i have had the entire power head off and i could not find a thermostat do they have one internally? i never stripped my old power head as i had a replacement

its like this boat never wants to see the sand and salt

Triple
09-11-2018, 09:08 PM
http://www.marineengine.com/boat-forum/showthread.php?384998-Where-is-the-thermostat-1983-Mariner-50-HP

gazza2006au
10-11-2018, 06:29 AM
Thanks Triple about to head off to get some fuel and test her again i am hopping its just a bit of old impeller lodged somewhere otherwise if it is the impeller those ebay ones really are crap

Fed
10-11-2018, 07:09 AM
My first guess would be either the impeller key slipped out and the impeller just started slipping on the second run or you didn't top the water level up enough before the second run.
Those keys are slippery little suckers.

gazza2006au
10-11-2018, 07:59 AM
Could be i didnt have enough water level in the bucket fed but it would have been no more than 10mm below the impeller at the best, the impeller from ebay i was really sus of its quality it was a loose fit over the drive shaft so i had some concern

i just realized some #*@#@ scum bag has been in my boat they took my anchor, chain and rope leaving the bucket it was in, they opended my tackle box with all my big sinkers in it leaving the tackle box and leaving my life jackets i am pissed off BCF want $80 to $130 to replace my anchor there goes my afternoon fishing trip :(

gazza2006au
10-11-2018, 08:05 AM
I ran the engine for around 8mins this morning a small amount of water was coming out the exhaust ports same as the other day on the muffs and water was coming out the propeller but none out the pee hole i may need to look at the impeller housing maybe that is eating impellers as i noticed it had no limit when bolting it down the housing just kept squashing down i didn't want to under do it and have the pump leak but i didn't want to over tighten it either

ericcs
10-11-2018, 08:20 AM
drop the leg and jam a hose over the pick up tube, at least that will rule out blockage in the powerhead. i never trust dropping a leg into a bucket, had the same as you, works one go, then nothing the next.

gazza2006au
10-11-2018, 09:53 AM
I'm thinking the impeller is chewed up or the wrong impeller all together i will drop the gearbox later on today i was planning on doing it this morning and heading to the shop before 12 to pick up a quality impeller but ended up at the bolt shop so i will work on the trailer and do the motor during the week

Fed
10-11-2018, 02:02 PM
Unblock the pee hole fitting on the cowl or the pee hole rubber tube or the pee hole fitting on the cylinder head cover.

gazza2006au
10-11-2018, 02:11 PM
Hey Fed i have the whole pee hose disconnected so its a 8mm hole off the top of the powerhead it may have sucked up a piece of the old impeller I'm not sure untill i get it off again

gazza2006au
13-11-2018, 07:32 PM
Was looking for Moby Marine yesterday got lost and ended up at Hunts Marine picked up a new impeller, The ebay impeller i bought was so soft compared to the genuine impeller i would say it fell to pieces on the first start

the genuine impeller was easily 4 times stiffer than the ebay impeller

gazza2006au
17-11-2018, 05:11 PM
Dropped the leg today and the port in the pump was blocked with old impeller bits when the old impeller went it must have dropped all the veins down into the pick up of the skeg

new ebay impeller looked ok i was to buggered to worry about installing the genuine impeller as the ebay one looked good the pump cover slid strait over the impeller i should have stopped right here and installed the genuine impeller but i kept using the ebay one, got the engine running and it wouldn't pup water at idle i gave it a bit of throttle and she pumped heaps of water and cooled down

my day has turned into an absolute shit fight, the ebay impeller is to soft and its not acting in a centrifugal force way so i think the veins on the impeller are just folding back allowing water to pass over them

tomorrow i will install the genuine impeller and take her down to the river for a spin and to set that mad advanced timing whole at WOT should be interesting.... 45kph down the lake while i have my head and hands next to the flywheel

Andy56
17-11-2018, 07:37 PM
Dropped the leg today and the port in the pump was blocked with old impeller bits when the old impeller went it must have dropped all the veins down into the pick up of the skeg

new ebay impeller looked ok i was to buggered to worry about installing the genuine impeller as the ebay one looked good the pump cover slid strait over the impeller i should have stopped right here and installed the genuine impeller but i kept using the ebay one, got the engine running and it wouldn't pup water at idle i gave it a bit of throttle and she pumped heaps of water and cooled down

my day has turned into an absolute shit fight, the ebay impeller is to soft and its not acting in a centrifugal force way so i think the veins on the impeller are just folding back allowing water to pass over them

tomorrow i will install the genuine impeller and take her down to the river for a spin and to set that mad advanced timing whole at WOT should be interesting.... 45kph down the lake while i have my head and hands next to the flywheel

isnt it easier to take the prop off and put the leg in the bucket? :o:o:o

gazza2006au
18-11-2018, 09:38 PM
Andy i had the gearbox off today installed the new genuine impeller filled up the test barrel it pumps good for 15 seconds than nothing if i turn up the idle she pumps water steam comes out of the pee hole

Im taking it to the lake tomorrow to hopefully see it work but not expecting much to change

My pee hose goes to the top of the engine block than a hose runs down to below the powerhead with the outlet do u think it needs this hose attached to gravity siphon the water some how? I couldnt get the hose on so left it off for testing

scottar
18-11-2018, 10:12 PM
If it pumps and then stops, my money is on a chunk of impeller still floating around that eventually makes it's way somewhere and blocks the flow.

gazza2006au
19-11-2018, 06:35 AM
Yeah i thought that to Scottar i watched a guy on youtube last night hook a hose up to his pee hose and back flysh the engine

Andy56
20-11-2018, 03:50 PM
I meant to do the timing test, pull the prop off and drop the leg in a bucket. Shouldnt be much turbulance.

Gon Fishun
20-11-2018, 04:43 PM
I meant to do the timing test, pull the prop off and drop the leg in a bucket. Shouldnt be much turbulance.

You need the prop or a test prop to put the motor under the correct load.

Andy56
20-11-2018, 06:02 PM
You need the prop or a test prop to put the motor under the correct load.

Ok, i just saw 5400rpm and i didnt think the timing changed under load or no load.

gazza2006au
20-11-2018, 06:05 PM
Called around again to find a shop to do my timing this time i called Wollongong a Mercury dealer and the wait is 3 weeks and it depends on the condition of my engine so I'm just going to wing it and take it down the river/lake hopefully later in the week

ericcs
20-11-2018, 06:30 PM
as you are probably aware, the advance is mechanical(so load is not critical), so you should see the timing plate rotate as you wind on the throttle, thus advancing the timing. if you drop the leg in the water without the prop, take a lead off no.2 or 3 plug(assuming its a 3cyl.). the motor won't rev as high, but the timing will still advance. adjust as required.

gazza2006au
20-11-2018, 09:41 PM
I'm just going to do it as per the manual mate i have set the cranking timing to 28 degrees which should put me in the ball park of 23 degrees at wot i think that is my understanding than i need to fine tune it to 23 but 28 cranking gets me in the range that wont melt a piston

the work shop manual is really crappy hard to understand

gazza2006au
22-11-2018, 03:28 PM
Took her down the lake my cousin was sitting in the xtrail with foot on brake i started her up done the first test it showed 24 degrees at WOT throttled back made adjustments, throttled up 23.5 degrees throttled back made adjustments 23 degrees bang on

the power of the engine increased probably 1/4 extra once i hit the right timing the engine had that nice WOT rorrr of a 2 banger

still not pumping water at idle tho with a little rev she starts pumping do u guys think i might need a whole new pump kit? kind of baffled by this the housing looked fine, i took the intake grate off today and checked for left over impeller bits couldn't find anything

Aussie123
22-11-2018, 03:36 PM
Sounds like the wear plate may be worn.

Dignity
22-11-2018, 03:49 PM
I'm not sure if this was covered but what does the thermostat look like, my little 30hp was playing up at low revs, the thermostat was stuffed, replaced it and worked well afterwards.

gazza2006au
22-11-2018, 03:53 PM
Aussie the top plate looked ok i might have ot take it off for another look

Dig no thermostats on this model as i thought the same thing

kind of thinking the only thing it can be is the pump however running it at WOT for 1 to 2mins it never got hot it only reached running temps

scottar
22-11-2018, 07:54 PM
Took her down the lake my cousin was sitting in the xtrail with foot on brake i started her up done the first test it showed 24 degrees at WOT throttled back made adjustments, throttled up 23.5 degrees throttled back made adjustments 23 degrees bang on

the power of the engine increased probably 1/4 extra once i hit the right timing the engine had that nice WOT rorrr of a 2 banger

still not pumping water at idle tho with a little rev she starts pumping do u guys think i might need a whole new pump kit? kind of baffled by this the housing looked fine, i took the intake grate off today and checked for left over impeller bits couldn't find anything

Personally I never do just an impeller change - but in saying that I don't change my water pump every year either. A full pump is where I would go next but only after removing the leg and stuffing the hose into the water tube to run it to see if then works. If it's all good on the hose - fit a new pump. If not you will need to look deeper.

gazza2006au
22-11-2018, 08:25 PM
Scottar yeah i hear ya, i'm thinking it could be the whole pump there are like 5 gaskets and seals in the pump i have only removed the pump top cover i will pill it apart and see

gazza2006au
23-11-2018, 08:10 PM
Removed the gearbox late this afternoon took the impeller out and noticed there were no water pick up pipe seal all fixed now something so simple... i had looked down thru the top of the port but the seal goes up thru the bottom of the housing