98 merc 5.0 overheating on driverside only

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poor boater

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I have a 5.0 merc alpla one gen two. was given as gift boat sat for three years have rebuilt carb and have it running. after idleing for 20-30 minutes the elow temp is 135F, while the other side is 105. took out to lake and was running around 130 while moving gear and getting set up. took kids tubing and thought boat was on fire put i.r. gun on it and elbow was 215F. opened elbow found quite a bit of metal debris in ports. I assume the entire manifold needs to be looked at but can they be cleaned or just replaced and what if any signs to look for if the motor on that side.
 
P

poor boater

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Messages
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Re: 98 merc 5.0 overheating on driverside only

went through everything again and found that the side in question had the valve on the inlett closed down 80%. just got the boat fo free from family. upon tryin to open the damn valve the plastic cap broke does any one know if the can be replaced or am i screwed.
 
Bondo

Bondo

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Re: 98 merc 5.0 overheating on driverside only

poor boater said:
went through everything again and found that the side in question had the valve on the inlett closed down 80%. just got the boat fo free from family. upon tryin to open the damn valve the plastic cap broke does any one know if the can be replaced or am i screwed.
Click to expand...

Ayuh,... What Valve,..??
 
P

poor boater

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Joined
Jul 5, 2011
Messages
10
Re: 98 merc 5.0 overheating on driverside only

looks like either my uncle or the shop he was using in WA. installed a shut off valve instead of the drain valve the manual says should be there. removed the exaust manifold there is some build up in there but not what i would have expected. Was thinking about running some clr or a low ph mix through it to see what comes out instead of buying a new manifold any sugestions?
 
Y

yomamaho

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Jul 8, 2009
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Re: 98 merc 5.0 overheating on driverside only

Put an 18 inch piece of throttle cable in a drill and ream it in and out through manifold. As long as the flat edges where gaskets go are smooth and not to far out of shape from erosion you should get more use out of manifold. Trick i learned from an old salt that got me 2 more years out of manifolds on my boat. Theyre espensive.
 
Bondo

Bondo

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Re: 98 merc 5.0 overheating on driverside only

to see what comes out instead of buying a new manifold
Click to expand...

Ayuh,... Ya can Roll the Dice, like yomamaho, or replace 'em like most Saltwater boaters...
 
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