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Closed cooling system overheating

I have a 260 hp m/c with inboa

I have a 260 hp m/c with inboard and after replacing the risors and manifolds I have a overheating problem. the hoses were checked and in the right location sea cock open. Manifolds are too hot to touch but elbows ok .I added coolant Does air have to be bleed from the system? If so what is the proceedure? Kevin
 
"Looked for a pipe plug in the

"Looked for a pipe plug in the thermostat housing. with engine cool, remove the plug and add A/F thru HX until coolant appears at the pipe plug opening. reinstall plug. finish filling HX.

Some, depending upon instlled angle of engine, require a couple heat up-cool down cycles to get all the air out.

Don't forget to add some coolant to the overflow bottle. Remember to check the bottle over the next few trips. I found my big blocks will take about three trips to get all the air out."
 
"Thanks for the info. As soon

"Thanks for the info. As soon as the hericane like rain stops I'll check. I don't remember seeing a plug in the thermostat housing,if not is there another way to remove the air.Kevin"
 
"I checked the 85-89 GM and t

"I checked the 85-89 GM and the small block vortec service manuals - both had the same verbage - plug on top of thermostat cover...

I imagine you could pull the tstat and fill the block. reinstall tstat and then fill the manifolds. Big PITA...

I'd bet if you run it thru a couple cycles, it will purge the air as long as you keep the overflow bottle at least half full when hot. I found warming mine up is fastest by starting and fast idle for a minute, then idle on teh stop for another minute, then push it into fwd, while still tied in the slip...It takes less than five minutes in December so doing it now should take two minutes. Cool down is helped by leaving the motor box hatch open with the bilge blower running. A 20-24" window fan will increase that if needed."
 
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