I have a Yanmar 3HM that is repowering the original Atomic 4 aboard a 1969 Chris-Craft Cherokee 32 (Yes, Chris-Craft DID make sailboats!) which I bought last year. It sat at the dock sit for the better part of 9 years idle as a floating hobby boat (that just sat and rotted...ugh...) and "shag-shack" (for lack of a better term) for the previous 2 owners, and now, a year later, I was finally able to get the engine fired up. While the engine (now) fires up on the first try every time (that took awhile), the problem I am having is that there are only about 5-6 DRIPS per second coming out of the exhaust (and then, only at higher RPMs).
I've replaced the impeller with a brand-new Yanmar-certified one, checked to see that the seacock was open (yes, it was), checked the water filter (it's actually, believe it or not, fine and flows nicely), cleaned out the pump assembly thoroughly with both fine-grit sandpaper (!!!) and a vinegar solution, replaced the gasket (also with a Yanmar) with a new one, and...still nothing. Now, there are no leaks, and every thing LOOKED good, especially after I cleaned out the out-flow hose, which was COMPLETELY clogged with salt and mineral deposits, but, alas, still no water flow.
I hooked up a hose to our fresh-water supply from the marina (which has a very high pressure...actually, a little TOO high, truth be told, but that's neither here nor there) directly into the thermostat/bypass connection coming from the water pump, but still...nothing. I bypassed that directly and put it on the manifold intake, but again, nothing. No water, despite the pressure, was coming out of the exhaust.
Since this was repowered, it doesn't have the smooth flow-through of the original Atomic 4. That is, there isn't a nice mixing elbow going up to a vertical bend in the exhaust and out of the boat. Instead, from what I can see, it goes through TWO 90° elbows - one at the exhaust mix and another out of the muffler. I've tapped them with a mallet to see if this could loosen up anything that might be in there...hence, the drips I'm getting now.
I know that there is a blockage in there...somewhere...but the problem is that the Yanmar is a much larger engine, and I can't really get to where I could disconnect any hoses to see about cleaning them out in the "traditional" way (i.e; scraping out the crud with a screwdriver) without playing contortionist Yoga master...though I may have to before this is done.
What would you recommend in flushing the engine out? I've considered 50/50 mix of muriatic acid or some CLR, even just another vinegar solution, but am not certain about how I would get it in there, considering the strange setup that is in place now. I have a spare bilge pump (Rule 360) that I could probably use to keep the pressure on from a bucket intake, but that's about it. I also don't want to damage the hoses or any metallic parts, especially in the heat exchanger, so I'm a little leery about the acid flush. It IS, after all, an 8+ year-old engine (and I know that the parts haven't been changed in that time, despite the fact that they appear to be in good shape, especially all of the rubber hoses).
The engine runs strong, but there is just no flow, other than the drips.
Any help would be GREATLY appreciated.
Thanks in advance!
I've replaced the impeller with a brand-new Yanmar-certified one, checked to see that the seacock was open (yes, it was), checked the water filter (it's actually, believe it or not, fine and flows nicely), cleaned out the pump assembly thoroughly with both fine-grit sandpaper (!!!) and a vinegar solution, replaced the gasket (also with a Yanmar) with a new one, and...still nothing. Now, there are no leaks, and every thing LOOKED good, especially after I cleaned out the out-flow hose, which was COMPLETELY clogged with salt and mineral deposits, but, alas, still no water flow.
I hooked up a hose to our fresh-water supply from the marina (which has a very high pressure...actually, a little TOO high, truth be told, but that's neither here nor there) directly into the thermostat/bypass connection coming from the water pump, but still...nothing. I bypassed that directly and put it on the manifold intake, but again, nothing. No water, despite the pressure, was coming out of the exhaust.
Since this was repowered, it doesn't have the smooth flow-through of the original Atomic 4. That is, there isn't a nice mixing elbow going up to a vertical bend in the exhaust and out of the boat. Instead, from what I can see, it goes through TWO 90° elbows - one at the exhaust mix and another out of the muffler. I've tapped them with a mallet to see if this could loosen up anything that might be in there...hence, the drips I'm getting now.
I know that there is a blockage in there...somewhere...but the problem is that the Yanmar is a much larger engine, and I can't really get to where I could disconnect any hoses to see about cleaning them out in the "traditional" way (i.e; scraping out the crud with a screwdriver) without playing contortionist Yoga master...though I may have to before this is done.
What would you recommend in flushing the engine out? I've considered 50/50 mix of muriatic acid or some CLR, even just another vinegar solution, but am not certain about how I would get it in there, considering the strange setup that is in place now. I have a spare bilge pump (Rule 360) that I could probably use to keep the pressure on from a bucket intake, but that's about it. I also don't want to damage the hoses or any metallic parts, especially in the heat exchanger, so I'm a little leery about the acid flush. It IS, after all, an 8+ year-old engine (and I know that the parts haven't been changed in that time, despite the fact that they appear to be in good shape, especially all of the rubber hoses).
The engine runs strong, but there is just no flow, other than the drips.
Any help would be GREATLY appreciated.
Thanks in advance!
