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View Full Version : risers and engine heat? MCX 07


hawaiianstiln
06-11-2009, 12:51 AM
I took my boat out for the first time tonight and everything ran super great. Oil pressure, eng temp all looked great (by the book). However, I noticed that the risers were SUPER SUPER hot and there was just a lot of heat coming from that engine compartment after running it for 20 minutes at all speeds (loaded and unloaded ballast). After bringing it back home (25 minute drive back), I turned the key to on and the temp guage still said 160. Isn't the water suppose to cool those risers down?

My previous malibu monsoon engine didn't seem to get hot like that if I recall. I guess the important part was that the engine temp was at 160 like normal. However, is it normal for your risers and other parts to heat up that you can't touch it but for maybe a few seconds.


That MCX sure is a SWEET engine for that 2007 X2. MORE than enough power.

JimN
06-11-2009, 01:08 AM
I took my boat out for the first time tonight and everything ran super great. Oil pressure, eng temp all looked great (by the book). However, I noticed that the risers were SUPER SUPER hot and there was just a lot of heat coming from that engine compartment after running it for 20 minutes at all speeds (loaded and unloaded ballast). After bringing it back home (25 minute drive back), I turned the key to on and the temp guage still said 160. Isn't the water suppose to cool those risers down?

My previous malibu monsoon engine didn't seem to get hot like that if I recall. I guess the important part was that the engine temp was at 160 like normal. However, is it normal for your risers and other parts to heat up that you can't touch it but for maybe a few seconds.


That MCX sure is a SWEET engine for that 2007 X2. MORE than enough power.

The raw water is supposed to cool the exhaust, risers and manifolds. Check the flappers and flanges for blistering and check your impeller. While you're at it, make sure the oil cooler is clear of any obstructions. I have read that Eurasian Millfoil has spread West of the Rockies, and it's a big problem for raw water cooling systems.

hawaiianstiln
06-11-2009, 02:11 AM
hmmm, well I did take the impeller out last night and look at it since I bought the boat used. The impeller looked brand new (only 42 hours on the boat). I stuck it back in, but is there a chance that I could have shuved the impeller in wrong with the blades folding the wrong way?

Never heard of Eurasion Millfoil, but this was the first time in AZ waters. This boat was previously near the bay area.

Are you talking about the flappers on the back of the boat? Not sure what exactly you are talking about with the flanges and flappers

Sodar
06-11-2009, 02:30 AM
hmmm, well I did take the impeller out last night and look at it since I bought the boat used. The impeller looked brand new (only 42 hours on the boat). I stuck it back in, but is there a chance that I could have shuved the impeller in wrong with the blades folding the wrong way?

Never heard of Eurasion Millfoil, but this was the first time in AZ waters. This boat was previously near the bay area.

Are you talking about the flappers on the back of the boat? Not sure what exactly you are talking about with the flanges and flappers

JimN is not quite up to speed on the newer boats. The '07s do not have flappers on the exhaust, so there is nothing to check.

Since your boat is an 07, I am guessing you have the Cat exhaust. By design, these manifolds run at a higher temp than average.

Did you smell/see any suspicious smells/sights in the engine compartment when you checked it out? ie. burning rubber smell or super soft engine hoses.

My guess is that all is well with everything.

As always, let the boat idle a few minutes before shutting it down for the day. The cooling water is only circulated while the engine is running. In my '07, it is common for the temps to stay high for about a half hour before it starts to cool down.

hawaiianstiln
06-11-2009, 02:39 AM
no weird or burning smells at all. No soft hoses, but I did check that..

Maybe I will pull out the impeller and make sure the impeller blades are not jacked up. I guess I thought the engine would fix the blades being folded down the wrong way.

hawaiianstiln
06-11-2009, 02:51 AM
Just checked the engine temp again by turning the boat back on (not cranking it tho) and the gauge still reads 120 degrees. We got off the water almost 4 hours ago and the engine cover has been open the entire time. I also felt the risers and they are still pretty dang hot. The hoses are kind of soft I would say. However, like I said, this is the first time out with this boat and just want to make sure things are good before we ride on Saturday morning.

Maybe I’m being a little too meticulous. :)

JohnE
06-11-2009, 09:30 AM
I stuck it back in, but is there a chance that I could have shuved the impeller in wrong with the blades folding the wrong way?



If you put it in the wrong way it would right itself as soon as it spins.

vision
06-11-2009, 10:15 AM
If you have an MCX with CAT (was not sure if CAT/EX started in 07 or 08) then hot risers is likely normal. But, as Sodar said, there was a recall on certain CAT risers for deficient water circulation which lead to higher than normal temps and melting of the connecting rubber exhaust hoses. So if there is a burning smell or the hoses appear melted anywhere, you may need new risers.

Temp of 120 4 hours after running is normal. The heat mass of an engine is huge.

JimN
06-11-2009, 10:18 AM
JimN is not quite up to speed on the newer boats. The '07s do not have flappers on the exhaust, so there is nothing to check.

Since your boat is an 07, I am guessing you have the Cat exhaust. By design, these manifolds run at a higher temp than average.

Did you smell/see any suspicious smells/sights in the engine compartment when you checked it out? ie. burning rubber smell or super soft engine hoses.

My guess is that all is well with everything.

As always, let the boat idle a few minutes before shutting it down for the day. The cooling water is only circulated while the engine is running. In my '07, it is common for the temps to stay high for about a half hour before it starts to cool down.

If I had seen the year of the boat, I wouldn't have mentioned the flappers but you're right, I'm not up to speed on the newer boats.

snork
06-11-2009, 10:48 AM
The cats on your exhaust manifold will get really hot by design, its not uncommon for your engine to remain hot due to the internal block water temps. Be careful when draining your exhaust manifolds.

JimN
06-11-2009, 11:23 AM
Just checked the engine temp again by turning the boat back on (not cranking it tho) and the gauge still reads 120 degrees. We got off the water almost 4 hours ago and the engine cover has been open the entire time. I also felt the risers and they are still pretty dang hot. The hoses are kind of soft I would say. However, like I said, this is the first time out with this boat and just want to make sure things are good before we ride on Saturday morning.

Maybe Iím being a little too meticulous. :)

Cast iron retains heat well, which is why radiators for houses and furnaces were made from it. Even after the fuel had run out, it would still radiate heat. In a motor, consistent temperature is a good thing for combustion and without a fan blowing on the motor, it will take quite a while to come down to air temperature. It's a matter of mass, time, influence on heat lost and temperature differential.

hawaiianstiln
06-11-2009, 11:34 AM
yes, they are the new risers.

Okay, thanks all for your input. I just got back from another lake test this morning and it stayed at 160 the entire time. I ran it for a good 30 minutes at all different RPM's (loaded/unloaded ballast too).

Yah, those risers just seem to stay hot, but keep the same temp. I then hooked it up on the fake-a-lake when I got home to make sure enough water was coming out and plenty came out.

Thanks! :)