It's natural for one exhaust to get roughly 20 degrees hotter than the other. They still should not exceed 120-130 degrees. As previously stated, running it on the trailer if you have a low water pickup can be an issue. I had a boat we did a shifter install on the other day, and when we fired it up on the trailer to check the shifting, when we reved it up, the alarm would sound. The boat had the CMI kit, and the headers were pretty hot. We were using side ear muffs, with a ton of water, We plugged off the front, and it was fine. The rear location of the heat sensor, does make the sensor a little warmer, but nothing that will casue the alarm to sound under normal operating conditions. We've had a couple of installations where the the lower merc fittings were bleeding off water and caused the exhaust to get hot. The upper hose should not be kinked. If it is it will cause a slowing of water flow through the system, and not only sound the heat alarm, but also possibly hit the pressure sensor on the water system. Check for hose kinks, if the hoses are good, check the lower fittings to make sure they are not bleeding off water. This can be done by pluggin the drainback line. At that point there is nowhere else for the water to go. The only other potential issue is a mis-alignment issue with the tailpipe and exhaust boot. Some exhaust boots have a rubber inner stop that hangs down in the exhaust boot roughly 3/16" of an inch. If that boot is crammed up against the water outlet of the riser, it will slow the water flow. If you need any further assistance, please let me know.

pictures
 

heres some pictures of the install and how they look, again they look awesome and sound awesome, just a few bugs to work out, i really wish dana marine was close cause im sure they would have this fixed in no time.. might have to send a plane to pick one of them up for the weekend:evilb:

forgot
 

also you'll notice i had to make a different hose on the port side so the water would flow better, theres a lack of water flow to this side of the motor, i know that much!

Ritts, I had the same issue with my Dana exhaust port side was getting hot setting off temp sensor..what my mechanic did (Jaime @ Lakeside) was get more water flow to the port side by removing the drain back valves and installing a adjustable valve in where the Dana piece is in the above pic that way you can tune the water pressure to port & starboard side and get the temps on each side very close....been running my boat that way for a month now with no issues at all as a matter of fact ran this past weekend (Fri, Sat, Sun) and boat ran flawless.

Unfortunatley Dana was NOT a big help to Jaime and myself because at the time they said they had no issues like mine so Jaime was behind the solution....good luck


Undertaker

Using a scan tool to observe the left and right exhaust manifold temperatures on a fully stock 496HO with the earlier Cool Fuel System, they both read ambient at start but as they warm up and stabilize in temperature the same side is always about 20*F hotter than the other side. I can not say which at the moment. I assume it has to do with the sea water cooling different things on the different sides of the engine and likely water could be hotter on one side than the other before it enters the exhaust manifolds.

This same temperature differential now exists since installing the Dana's.

Jaime @ Lakeside did put my motor on his laptop while he was running the boat port side was 60 degrees hotter than the starboard thus the temp sensor going off. On a stock motor there is a degree difference between port & starboard, port being a little hotter like 20 degrees, but not 60 degree difference.

PM me if ya need any more info, it fixed my problem.


Undertaker:D

On my stock 496 the port side runs about 15* warmer.

Did they tell you to go to the hardware store?:evilb:

They told me to change props and get my tach looked at......
it is a long story.....will not get into it here

Undertaker:D

Makes me glad that Dana changed their price after the first of the year. I almost had these same headaches and the less than stellar results that I have read about. Though there has not been much talk about them. I am sure they sound good and look purdy.