Mercruiser 496HO Mag Risers
 

I need to replace my 2001 496 HO Mag Exhaust risers. I would like to use a set that are longer (use less rubber exhaust hose) and risers that will bolt up to my stock manifolds. I also do not want to screw up the Guardian System, or have to do any recalibrations. Jeff

Re: Mercruiser 496HO Mag Risers
 

You say you need to replace, is there something wrong with them?

Re: Mercruiser 496HO Mag Risers
 

I had a local Marine Replace a broken bellhousing and in turn when the motor was reinstalled the exhaust tips from the risers burnt through one of the rubber exhaust hoses. When I took the boat back they stated that they had to change the rear angle of the motor (high) to align with the drive, They also took and changed the exhaust port in the risers for more clearance around the rubber hoses. I noticed that the rubber hoses felt a lot warmer than before the change. I want to go to a longer riser with less rubber hose if possible? Jeff

Re: Mercruiser 496HO Mag Risers
 

something is very wrong with that!!!! If your exhaust was ok before the broken bell housing then it should not change ....I will assume you are talking about the flywheel bell housing.... in that bell housing there are two motor mounts pressed in, If these mounts are pressed in correct and the correct bellhousing was installed correctly and we will assume that there was no alighnment issues everthing will be ok....when the motor is reinstalled the alignment should have been checked...I will also assume that that the boat had no problems before the broken bell housing....like bad ujoints, or bad coupler....If all those parts are ok then something is very wrong.

Re: Mercruiser 496HO Mag Risers
 

Something is definitely wrong, most likely with the re-installation some how. The exhaust should not get hot enough to burn the hose. Make sure you have good water flow from that exhaust. If you have a scan tool available, it can read the exhaust temps. Jboater is correct, there is something hokey with this adjustment. What originally broke the bell housing? That appears a little strange in itself.

Re: Mercruiser 496HO Mag Risers
 

Sounds like the motors were run with the air-actuated drain pumps open not getting water to the risers and therefore heating up and burning the hose. No other reasonable explanation to me. Maybe they had the alarm disconnected too? But i agree with the Hopper, something ain't right and it sounds like some damage control going on. I'd demand a little more "logical" explanation from the mechs...