riser petcock / no flow

steve n carol

Chief Petty Officer
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May 8, 2004
Messages
459
merc 225, 188hp 302 ford. Got the new BARR log style and risers, T-stat and hoses. Put the muffs on 'and farred that mamma uhp'. Prior to starting the engine, I checked water flow into the block and manifolds by opening up the petcocks. water came out of all of them except the petcock on each riser. When I installed the logs and pet cocks haha, I had to clear away the blue thread sealer. <br />Q), is there suppose to be water flowing through the riser petcocks? <br />after warm up and carb adj. While the engine was running, I opened these petcocks, nothing came out. logs were hot to the touch, risers a little warmer, the U pipes below the risers were much cooler, just warm. The gauge stayed at 175 for about 30 minutes. then went up to about 200. Well, no water in the oil....thats a good thing. The BARR risers are 'an improved style for better cooling'. I used the S.S. block off below the risers, just as with the originals. Any thoughts about the riser petcocks?
 

crazy charlie

Vice Admiral
Joined
May 22, 2003
Messages
5,581
Re: riser petcock / no flow

Too much sealant will close off the water flow that why no sealer is recomended when installing.Take the riser off and see if there is blockage.Charlie
 

steve n carol

Chief Petty Officer
Joined
May 8, 2004
Messages
459
Re: riser petcock / no flow

Charlie, So, there should be H2o flowing out the petcocks, (riser)? would it matter, warmed up, (t- stat) or cold? BTW, this is a raw water system.
 

Bondo

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Re: riser petcock / no flow

BTW, this is a raw water system. I used the S.S. block off below the risers<br />
The Block-Off Gaskets are for Freshwater Cooling Systems.............<br /><br />You're pumping water Into your system, With No Way Out.......<br /><br />Where,+ How Much water was coming Out of the motor when you had it running ?????????
 

steve n carol

Chief Petty Officer
Joined
May 8, 2004
Messages
459
Re: riser petcock / no flow

Bondo, "Where,+ How Much water was coming Out of the motor when you had it running ?????????" <br />This is a tough one to answer as I was not measuring this. I was monitoring this as it was/is important that the muffs hadn't slipped off. Water was squirting out from around the muffs, (typ.), and exiting out form the prop area. When the temp gauge showed 190, (new marine T-stat), I went and stuck my hand on the "Y" pipe beneath the riser. this was only warm and cooler than the log and/or riser. Next I went to the stern, checked the water hose connection, placed my hand in the exhaust water, this was hot enough to burn but not to the boiling point. <br /> "The Block-Off Gaskets are for Freshwater Cooling Systems............." <br />I read another post, (yours?), yesterday regarding this same issue on a similar (merc 888 i think it was), with raw water cooling. You had posted much the same reply. The author of that reply, mentioned that this Cold water had to pass through the log to warm up in order to open the T-stat, then Hot water to exit out the riser. <br />With all this chatter you would think it was Carolyn typing! In truth it's the coffee talking.<br />Now, more coffee, I believe you run a GM stroked small block, Fig. #6 page 7D-4 in my mercruiser manual, shows an exploded diagram of a standard cooled NOT utlizing a block-off plate. page 7D-2 Fig. #2 model 225 shows this plate in use. (truth..I am not comfortable w/the block off plates). I will be investigating the riser pet cocks and the engine circulating pump, (salt water), as well as replacing the water and oil sending units. more coffee now.
 

qystan

Petty Officer 1st Class
Joined
Apr 26, 2004
Messages
291
Re: riser petcock / no flow

Steve n Carol<br /><br />When Bondo mentioned Freshwater Cooling System, he meant Closed Cooling System.<br /><br />If yours is a standard cooling system (never mind salt or fresh) it must not use the blockoff plates, else the cooling water cannot exit the engine.<br /><br />Your book differs from mine, section 7 in my book is for the exhaust, section 6 is the cooling and it shows only seawater cooled and closed cooling options only.
 
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