hi guys, still having headace. twins 470 i just got one rebuilt, since the mechanic install it i has been having a very high back pressure i busted up all the coolant hoses already. i found the hose from the radiator cap that goes to the rezevor it was clogg from inside the cap i cleac that but still having the problem. what i notice if i drove the boat say at 2500 to 3000 rpm i might be ok but if i go any thing over i will get the hoses busted or overheat. the mechanic says i might have some exaust flapper stuck in the exaust system. any info will be great<br /><br />this mec already took me for a ride so now i want to help my self. thanks.
