Starboard exaust manifold runs hot, while the port exaust manifold stays cool?.???

[alldodge]

Re: Starboard exaust manifold runs hot, while the port exaust manifold stays cool?.??

My boat does this. If I put her in neutral and rev her a bit they both become the same temp. Figured it was not a big deal.

I agree, I don't think the OP has an issue. Mine does similar on both boats. While I have an issue holding my hand on one of the rises it will not burn me over the short period, just hurts. This is a difference of around 15 degrees which is enough to cause skin problems. Need an IR thermometer to check.

 

[TampaBoater]

Re: Starboard exaust manifold runs hot, while the port exaust manifold stays cool?.??

So, I took out the starboard riser and there is no visible obstruction. I guess its like the last couple of posters said. Maybe its just thr way it goes.

 

[tazrig]

Re: Starboard exaust manifold runs hot, while the port exaust manifold stays cool?.??

You might want to drain the block then pull the right manifold and check for obstruction there also. The water has to go through that before it gets to the riser. I'm just a little concerned about the riser being too hot to touch. It should be cool to very warm but when it gets too hot to keep your hand on it there is usually a blockage somewhere. Assuming you have plenty of water pressure going to the muffs it shouldn't get that hot.

 

[TampaBoater]

Re: Starboard exaust manifold runs hot, while the port exaust manifold stays cool?.??

You might want to drain the block then pull the right manifold and check for obstruction there also. The water has to go through that before it gets to the riser. I'm just a little concerned about the riser being too hot to touch. It should be cool to very warm but when it gets too hot to keep your hand on it there is usually a blockage somewhere. Assuming you have plenty of water pressure going to the muffs it shouldn't get that hot.

Well it is not like it gets super hot that you can't touch it. Like the time I was running the boats and I got the hole in the manifold I put my hand to the starboard the riser and it was pretty hot enough to take it off within a few seconds while the ports manifold was not as hot.

 

[tazrig]

Re: Starboard exaust manifold runs hot, while the port exaust manifold stays cool?.??

I guess I misunderstood. So long as you can put your hand on it and leave it for a few seconds you should be fine. It IS normal for one side to run a little hotter than the other. I thought you had one side that was warm and one side that was too hot to touch.

 

[Lou C]

Re: Starboard exaust manifold runs hot, while the port exaust manifold stays cool?.??

It really depends on how you are running the boat. If I run my Cobra on the muffs each manifold is about 85-90 degrees on the IR temp gun....that feels just warm not hot. If its in the water just idling same thing. When I run it on plane and then come off plane the hottest they get is 125-130, that feels very warm but you can keep your hand on it. After a few minutes of idling it goes back down to 90 or so. Any hotter than those numbers then I start looking for problems.
If you can't keep your hand on it then it's probably hotter that 140 which is too hot if the engine is just idling.
You also might want to check the water flow from the Thermo housing to that manifold. You need good flow in and good flow out. What is the temp on the temp gauge and how old it the impeller?