Exhaust hose Burning through

[scorpion24]

1984 Scorpion,5.7 mercruiser,thru hull exhaust,it seems that the port side exhaust hose from the riser to my thru hull tips lasts about 3 hours and then burns through just past the riser,any ideas,the boat runs at about 160-170 degrees at 3300 which doesn't seem to bad to me.would a lean carb cause this pushing the exhaust temp up?

 

[Bondo]

Re: Exhaust hose Burning through

the boat runs at about 160-170 degrees at 3300 which doesn't seem to bad to me.would a lean carb cause this pushing the exhaust temp up?

Ayuh,... I'd sooner think there's some sorta restriction in that riser affecting the Water Flow...

 

[Don S]

Re: Exhaust hose Burning through

You didn't by some chance replace the manifold and/or riser on the other side did you? IF so, that would explain where the water went for the side that keeps burning the hose.

 

[scorpion24]

Re: Exhaust hose Burning through

Thanks for the info,I will check out the water flow,i did notice with the engine running and the hose opening was filling the bilge with water,both risers were replaced before the begining of the season.

 

[littlebookworm]

Re: Exhaust hose Burning through

if you replaced both risers at the beginning of the season, they shouldn't be the problem. Did you use the correct gaskets for the exhaust arrangement you have? Some have a restriciton hole and some do not. Check your gaskets and the mating surfaces. Also, check the exhaust pipe as it goes through the hull. Is it clear? Are there flappers in it? if so, are they working properly or are they frozen, clogging the exhaust? Check it all. Please let us know what you find. Hy

 

[scorpion24]

Re: Exhaust hose Burning through

I would like to thank everyone for their help and responces,come to find out the guys who did the work on the boat never replaced the risers.(nice black paint on the outside,I removed the port riser and found the water hole just about plugged up.I spent about an hour cleaning both risers and chipping away at the buildup,everything is together and I plan to take the boat out tommorrow to see if it worked,I will be using and infra red heat gun during the ride.Once again thanks for the help and I will post again after I see how it works

 

[scorpion24]

Re: Exhaust hose Burning through

Thanks everyone for the help,pulled off both risers and the water outlet slit was nearly plugged up,spent about an hour on each one of them and ran the boat pretty hard,both exhaust temps were way down and now the boat seems to be running down even cooler close to 150 degrees,once again thank -you for the help