merc thundblt 80hp 4cyl last straw

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iaincwil

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Jun 21, 2006
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still has no water coming through the tell tale with the hosepipe attatched to the water tube above w/pump should this be or is there a blockage somewhere poss the rubber gromet at the top

can I pull this pipe out and get it back in without removing the powerhead???????
ta!
mick
 
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Laddies

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Re: merc thundblt 80hp 4cyl last straw

Can't speak for you mick, but I can. Good Luck--Bob 8) Have ya just hook a garden hose to the water tube and checked the damn thing for water flow that way to see if the problem is in the bottom or top
 
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iaincwil

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Re: merc thundblt 80hp 4cyl last straw

yep have done that! and removed the cover over spark plugs to check for water flow and its only coming out the bottom if I block the bottom off there is no flow to the top inlet by the outlet to the tell tale pipe,
we have decided to put the whole thing back together with the new pump fitted and just give it another try and see if it works or not,
 
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iaincwil

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Re: merc thundblt 80hp 4cyl last straw

well someone said check out the thermostat!! does it have one ?? if so any idea where it is as I cant see anything I would recognise as a thermostat !!!!!
getting fed up with this now its one thing after another, we cant get new bolts for it anywhere as they are like whitworth or american coarse everything here is flamin metric, like all but one snapped when we took the cover off the spark plugs,

laters
mick
 
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iaincwil

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Re: merc thundblt 80hp 4cyl last straw

thank's I couldnt see anything like one ! so you any idea why there is no water getting through??
I have poked wire into every hole I can find and only found a little bit blocked, when we opened this thing up there were mussell's been growing inside it and white barnacle things as well

we have run it untill it started pushing steam out then stopped a bit quickly when I noticed no tell tale,

do you think it would be wise at this stage to just put everything back together and see if it will pump water through now?? the summer is gona be over soon!!!
 
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emckelvy

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Re: merc thundblt 80hp 4cyl last straw

If it's getting only minimal flow with a water hose hooked to the supply pipe down below, it's not going to get any better by putting it together and running it. That will only serve to overheat the motor even more and likely ruin it.

I think the key here was your comment about sea growth, sounds like it's pervasive in the powerhead and you really need to pull it down to check for obstructions at the upper end of the water tube, and likely the passages inside the exhaust cover are all blocked off and you'll need to pull the exhaust cover for inspection.

This is the nasty part as the cover bolts get all salted up and can be a real "bugger" to remove:devil:

If you encounter a frozen bolt, use heat from a propane or MAPP torch to free it. Don't use undue force as it'll break. No fun drilling stainless out of aluminum!!

Worst case, drill out the bolt heads then use Vise Grips on the stubs once you get the outer cover and exhaust baffle off.

I expect you'll find lots of Critter Remains inside, G'luck.

HTH............ed
 
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iaincwil

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Re: merc thundblt 80hp 4cyl last straw

aye we thought of doing that so looks like we got to get on with it,

right which is the exhaust box cover will have a closer look at that and see if we can get it of for a looksee, we took of the box cover over the plugs and its not too bad in there just like chalky deposit but every bolt barin one broke off we managed to get the remaining stud out but we cant get bolts for it anywhere up here as everything is metric and the bolts are something like a/coarse or whitworth definitely not metric,
does the water pipe pull out cos we cant get it out and can we get it back in without splitting the powerhead??

right be back shortly
mick
 
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iaincwil

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Re: merc thundblt 80hp 4cyl last straw

er!!! we have taken a cover off from the s/plugs where is the exhaust cover??
 
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emckelvy

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Re: merc thundblt 80hp 4cyl last straw

The exhaust cover is on the port side of the engine.
 
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iaincwil

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Re: merc thundblt 80hp 4cyl last straw

got it thanks!!!!!!! will be having a go at that asp. hope thats the final move getting sick of it now,

keep looking in will keep you informed on progress if any,

any idea where to get gaskets from?? if I can get material will be making them ourselves,

laters
mick
and thanks again
 
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iaincwil

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Re: merc thundblt 80hp 4cyl last straw

well finaly fixed it we tried to take off the P/H but couldnt move it so to get to the water jacket cover is almost a no go, so thefairing around the bottom we cut in half so we could get in we will stitch it back together! anyway took off the cover and there was 3/4" of dead reamains in there and two of the small holes that go into the water jacket were completely blockedso spent 2 hrs, poking around and flushing out than put the whole thing back together and turned the engine over wi nae plugs and yes we have wtaer from the tell tale,
just to finish off tomorrow and see if she runs, cor blimey mate what a job BUT having done it once would not hesitate to have another go,

thanks for all the help, and dunit make yer feel good when yer right!!

thanks again
mick
 
lilmandavis

lilmandavis

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Mar 9, 2006
Messages
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Re: merc thundblt 80hp 4cyl last straw

i would of scraped all the carbon out of around the exaust ports as well. i took a drill and drilled out the corrosion to get it back to normal sizes in the flow throughs on the exaust cover. theres only about a 1/4 inch for the water to flow through it seems so its got ta be clean and free of corrosion and sea growth. i put anti sieze on my "new" bolts so that when the season is over ill take it back off and ream it out again. cause the salt down here sucks, but the fishin is great!!! i got rid of my 800. but i just upgraded to a 1400!! now goin through that.
power heads on these engines are actully easier to take off than the covers on the engines themselves.
 
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emckelvy

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2,506
Re: merc thundblt 80hp 4cyl last straw

If you run some Salt-Away thru the motor after each outing it'll help cut down on the salt deposits. They have an applicator you add the flushing solution to then it hooks to the hose and muffs flusher and feeds thru with the flushing water.

Glad we managed to get to the root of the circulation problem, a real bugger, eh wot?
 
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