Exhaust hose over heating on Crusaders

[Coppifan]

The hoses coming off of my engine elbows are overheating. The mechanic has torn the boat apart looking for a cause. There is nothing wrong with the engine. Exhaust hoses and one elbow were replaced. Water flow is good. Impeller and pump are good. Raw water intake is clear. Muffler doesn’t seem to have any blockage as far as we can see. Can’t figure out how you would even get the muffler out of the boat if had to.
Right now I have spent almost $2000 on this issue on my 2000, Tiara 31 Open.
Very frustrated! I’m about ready to give up boating and become a golfer!
Any thoughts?
 Thanks

Bill Eggert
Punta Gorda, Fl
Coppifan@aol.com

[Sans Peur]

Did you change out the impeller? It can look like good flow but not be enough. The shower heads should fill and flow from all around the head, if it is not enough flow the exhaust gasses won't be able too be cooled, especially the top portion of the hose, and you will get burning rubber smell when you throttle up.

[jclark003]

Good advice above. Definitely sounds like a water flow issue. Possible causes are plugged riser/shower heads/ manifolds, restriction in heat exchanger, oil or transmission cooler, collapsing intake hose or a raw water pump issue. given that you recently replaced one riser and both hoses are overheating I would start down by the pump and work downstream. Make sure the intake hose isn't collapsing, check the raw water impeller, cam and wear plate (any one can reduce flow) and then the heat exchanger and coolers. The diesel guys like to use something called barnacle buster to flush out the raw water loop. Might be worth a try. A muffler plugged up that bad probably wouldn't let the engine make power.

Golfing isn't cheap or low on the frustration scale either.

[Coppifan]

Good advice above. Definitely sounds like a water flow issue. Possible causes are plugged riser/shower heads/ manifolds, restriction in heat exchanger, oil or transmission cooler, collapsing intake hose or a raw water pump issue. given that you recently replaced one riser and both hoses are overheating I would start down by the pump and work downstream. Make sure the intake hose isn't collapsing, check the raw water impeller, cam and wear plate (any one can reduce flow) and then the heat exchanger and coolers. The diesel guys like to use something called barnacle buster to flush out the raw water loop. Might be worth a try. A muffler plugged up that bad probably wouldn't let the engine make power.

Golfing isn't cheap or low on the frustration scale either.

---

Thanks! “Shower heads”?

[jclark003]

Sorry the Raw water is injected into the exhaust stream at the tail end of the riser. It is sometimes referred to as the shower head. If it gets partially or completely blocked you won't get enough water cooling the exhaust gas. If you changed one or both risers and both hoses are still overheating the problem is probably somewhere else.

[reeltimebrad]

Ive had cooling issues from millfoil getting through my strainers and plugging up my oil coolers and the only way to clear them is to backflush the coolers. I then went to a finer screen one my strainers and have to clean them more often. My point is you'll still have water flow but it can be restricted enough in a place you would not think it should be that it causes problems downstream.

[Coppifan]

The mechanic has spent hours going over everything. Replaced hoses, risers, water pump, impeller. Getting good flow but the hoses are still heating up too much. It’s driving him nuts.
It’s driving me both crazy and broke. I’m almost ready to sell the boat as is....

[RMS]

My buddy had a brand new impeller which was faulty. Made him crazy with the overheating until he replaced the impeller a second time. Bob