Yamaha 25-ii retrofit: Piccolo

Sep 8, 2021
8
yamaha 25 mkii tall rig vancouver
The throttle cable to the Morse mt control snapped on my 25-II, and I’m in the process of replacing it; It was easy enough to pull out of the bilge.

The picture attached is the part that rotates and attaches to the 33c cable (the smaller part with the cotter pin). Could anyone confirm the larger rotating part is meant to be bent so much? I think the top part (circled) should be flat, and my copy has been bent by accident. Many thanks !

Piccolo
 

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Mar 6, 2008
690
Catalina 1999 C36 MKII #1787 Coyote Point Marina, CA.
It appears from your photo that you are right that the section near your finger is bent due to excessive force, but the bend near the hinge is made by a machine at the factory. I would recommend replacing this piece instead of straightening it as that would weaken the metal.
 
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Sep 8, 2021
8
yamaha 25 mkii tall rig vancouver
I will post my ongoing repairs / maintenance tasks for Piccolo here, to share findings and ask for help too.

The control line was pretty easy to fix. It cost about $50 USD, and was easy to thread through the bulkhead and hull. One thing that I did find confusing was finding the cable, as the cable was originally made by Morse, than that company got sold, bought by others, having names such as Telefax, SeaStar, Sierra International, and now Dometic. They are still the Morse cables.

My next task after fixing the control line, is to tackle the exhaust riser, mixer elbow, and muffler. Pics shown before and after removal + some cleaning up with a small screwdriver. To be honest, I'm leaning towards replacing the whole shebang as I don't trust it, even if I do manage to get the surface rust off. The mixer elbow downstream side had minor carbon buildup, but since I haven't been able to get the parts apart, I can't really see how bad the carbon buildup is inside.
 

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Sep 8, 2021
8
yamaha 25 mkii tall rig vancouver
I am looking at purchasing the HDI stainless steel mixer elbow and adaptor joint. One concern I have is that my original adaptor is 3" long before the threads. The HDI model has a shorter threaded model. I know that the elbow has to be above the waterline, so should I be concerned? Will adding a black pipe between the adaptor and the mixer elbow to gain the needed space do the trick?
 
Sep 8, 2021
8
yamaha 25 mkii tall rig vancouver
Last part of the exhaust setup, is the muffler. I have what I think is the original waterlift muffler, which was a really pain to get out of the boat. A friend gave me a Vetus, but the intake diameter is significantly smaller than the old muffler. Since it's downstream, and the water is not pressurized, I was thinking it should be fine, but am looking for comments / advice. I could put the old muffler back, or buy a new one, if the Vetus is risky?
 

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Sep 8, 2021
8
yamaha 25 mkii tall rig vancouver
If anyone is looking for ysm8 / ysm12 Yanmar exhaust parts, here are the part numbers:
  • Manifold Gasket 104211-13201
  • Exhaust Elbow 104211-13070
  • Joint 104214-13580
  • Mixing elbow 104214-13521
 
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Jan 7, 2011
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Oday 322 East Chicago, IN
Last part of the exhaust setup, is the muffler. I have what I think is the original waterlift muffler, which was a really pain to get out of the boat. A friend gave me a Vetus, but the intake diameter is significantly smaller than the old muffler. Since it's downstream, and the water is not pressurized, I was thinking it should be fine, but am looking for comments / advice. I could put the old muffler back, or buy a new one, if the Vetus is risky?
What is wrong with the old muffler?

if it is serviceable, that is the path of least resistance.

Vetus is a well-known muffler. I have a similar water-lift exhaust on my boat with a Yanmar 2GM20F engine. How much smaller is the inlet than the exhaust hose? You need to have a tight, vapor free connection, or you could be pumping CO2 into your boat.

Also, not sure how a muffler is “sized” to an engine, and the exhaust hose (capacity for the WL).

Greg
 
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Jan 7, 2011
2,908
Oday 322 East Chicago, IN
I am looking at purchasing the HDI stainless steel mixer elbow and adaptor joint. One concern I have is that my original adaptor is 3" long before the threads. The HDI model has a shorter threaded model. I know that the elbow has to be above the waterline, so should I be concerned? Will adding a black pipe between the adaptor and the mixer elbow to gain the needed space do the trick?
I assume your mean that the nipple is too short (standard on the HDI elbow).

You can purchase a longer riser from HDI…


Also, note that (I believe) the nipple has opposite threads on each end…so a standard pipe nipple probably would not work.

1635895495042.jpeg


Greg
 
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Sep 8, 2021
8
yamaha 25 mkii tall rig vancouver
What is wrong with the old muffler?
Hi Greg,

Before I removed the exhaust and muffler, I believed the latter was rusting (see attached photo for the mess left behind). But it was actually the rusting exhaust riser, and the heat wrap disintegrating.

I'll have to check the muffler again for leaks, but I think your reasoning is right on - it seems re-usable.
 

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