525 question
#1
Registered
Thread Starter
525 question
im looking at a boat with twinn 2004 525 merc's is there any known problems with this year of motors. if so what should i look for ?
thank's
mike
thank's
mike
#6
Charter Member
![](https://www.offshoreonly.com/forums/images/icons/charter_member_star.gif)
![Default](/forums/images/icons/icon1.gif)
From Powerboat Mag-Teague on Tech:
All three headers feature the CMI "cool collar" construction, which results in a small section of the primary tubes next to the head flange being nonwater-jacketed. The cool collar feature has virtually eliminated the cracking problems that used to exist on headers that have the water jacket extended to the head flange. It is the differential of temperatures combined with the different material thicknesses involved that causes the cracking on the old-style headers
All three headers feature the CMI "cool collar" construction, which results in a small section of the primary tubes next to the head flange being nonwater-jacketed. The cool collar feature has virtually eliminated the cracking problems that used to exist on headers that have the water jacket extended to the head flange. It is the differential of temperatures combined with the different material thicknesses involved that causes the cracking on the old-style headers