Riser rubber pipes on a 260HP Mercruiser? When to replace?

[Fiat4Fun]

Howdy, I have a 1986 Mercruiser with 260 HP V8, and the motor still has the original rubber riser pipes. There is a rubber pipe that comes off the riser, to a right angle metal pipe, and then another rubber boot that goes to the exhaust pipe "Y". Both sets are held in place with a pair of stainless hose clamps in each end. I suspect that water may be dripping out one side or the other, as I have had to tighten the clamps earlier this year.

Should these be replaced at a certain time? Boat has over 700 hours on it, and these are original. I am thinking that maybe these have shrunk over time an water may be leaking into the bilge.

Any thoughts would be appreciated
Thanks

 

[alldodge]

Howdy, I have a 1986 Mercruiser with 260 HP V8, and the motor still has the original rubber riser pipes. There is a rubber pipe that comes off the riser, to a right angle metal pipe, and then another rubber boot that goes to the exhaust pipe "Y". Both sets are held in place with a pair of stainless hose clamps in each end. I suspect that water may be dripping out one side or the other, as I have had to tighten the clamps earlier this year.

Should these be replaced at a certain time? Boat has over 700 hours on it, and these are original. I am thinking that maybe these have shrunk over time an water may be leaking into the bilge.

Any thoughts would be appreciated
Thanks

I use the old saying when in doubt, throw it out. Also add that I've seen a lot of old boots and only found a few which needed replaced. I'm mostly in fresh water so the impact is less. If your wondering, pull the boot off and make a close inspection in and out.

 

[Bt Doctur]

Sorry, dosent work like that. overheating usually destroys them from the heat of the exaust gas. There too high up to just leak when in the water.
Being a 86 could be the Y pipe has rotted thru , hyd connector block, water inlet tube, torn bellows, rotted transom

 

[achris]

I've worked on engines more than 25 years old with the original boots, and no problems. I would say your problem is more likely the aluminium tubes or the Y-pipe than the boots. Over time the aluminium corrodes and that builds up on the inside of the rubber. That's what leads to leaks. You need to pull the boots, properly clean the inside sealing surface and refit them. Check the aluminium surfaces too. If there's too much corrosion, replace them... I like to give the insides of the boots a liberal coat of grease before refitting. It makes them easier to remove in a few years time.

Chris.....