Hi new to the forum and also Sea Plum, a 1979 Hunter 27 Cherubini. I searched the forums and found some great information that ultimately contributed to me getting the little YANMAR SB8 roaring back to life in front of the previous owner and which resulted in me completing my purchase yesterday. She was loved by her previous owner however sat on the hard for 3 years after he retired and moved away and was no longer able to use her as he thought he once would.
Hoping someone can point me in the right direction if my below assumptions or plan is not correct. I have searched multiple forums, ran internet searches and read the YANMAR service manual. If anyone has any recommendation or advisory against my methodology any and all encouragement and criticism is welcomed. I look forward to be a contributing member of the board. Thank you in advance.
I only ran her for a 2 minutes and shut her down due to no cooling water being supplied through the engine. I will complete the regular maintenance, ie ,Oil change/filter/filter screen clean, alternator belt, thermostat, fuel filter, racor filter, charge or replace batteries and drain fuel tank in the near future. Main issues I see with the particular YANMAR SB8 are related to cooling and exhaust issues besides already mentioned maintenance above Below are the 3 main issues.
#1The water isn't pumping through block.
#2Calcification in block
#3Rusted and compromised exhaust elbow ie hole
I inspected and completed or planning on the following on her however all 3 of my issues cause me concern about water backflowing into exhaust ports. Is the issue of backflow only at the mixing exhaust tube? If I disconnect the hose from the cooling water outlet to the water mixing elbow do I bypass the chance of water entering ports? After reviewing the schematics of the piping diagram in the service manual this looks like the only interface between H2O and ports, can anyone confirm before I flood my engine? , welcome any input.
#1 Yesterday, I inspected impeller it seemed flexible and intact. I cleaned off old filter material and installed new gasket. I detached intake line from sea cock and cleaned inline sea strainer filter and re-filled strainer with water and thought I primed hose line with enough fresh water. I also ensured all hose clamps were tight and placed hose in 5 gallon bucket of water. Still no uptake of water, took off impeller cover off again and turned her over to be positive it was spinning and impeller didn't detach from hub.
Sounds like air leak or worn impeller to me, any other ideas? If water pump was bad would impeller still spin? I disconnected hose immediately after cooling water pump should water that I primed with just drip or flow past impeller maybe impeller is worn even though still intact and flexible. What product should be applied to new paper filters, is it a specific type of grease? I couldn't pull out old impeller out I tried but was getting to dark. I saw there are expensive pullers but also saw long nose pliers with a 90 degree bend should work. Going with pliers before buying an actual puller. There is no set screw correct?
My Next step this coming Friday was to install new impeller, gasket and replace water supply hoses because they are severely stiff. I had the five gallon bucket originally on the galley floor when I started engine, should I set the 5 gallon bucket on the sink so I can start a siphon to confirm its primed. Cold weather is coming, I noticed a drain cock near bottom of block if I can't get winterizing fluid in there can I just drain the block for the winter and possibly blow air through cooling system to expel any water if I disconnect cooling water tube from the mixing elbow.
#2There is severe calcification and a corroded engine anode. I read about Muriatic acid wash I plan to do a 15 to 1 acid rinse instead of buying a commercially available product.
My plan was to use PPE, proper acid handling precautions, remove thermostat and disconnect rubber hose at cooling water outlet from water mixing elbow and connect it to a bucket or a longer hose that exits boat. I was going to utilize a drill pump to get solution into block, let sit 15mins and flush and capture wash in 5 gallon bucket from the mixing tube hose add baking soda to acidic water to neutralize and dispose. Possibly repeat procedure if need be. Replace anode and thermostat after wash. Does this sound like the right plan, specifically with disconnecting hose from water mixing elbow?
#3 Replace exhaust elbow due to hole and visible smoke in cabin. My local Yanmar dealer told me the part is no longer available I found stainless steel elbow online and ordered that is aftermarket for the SB8. Seems simple enough as long as elbow unscrews from block. I was going to hit with PB rust blaster until part comes in? Any recommendations or pitfalls to avoid when replacing elbow that others experienced. I plan was going to use a big pipe wrench, to heat or not to heat. Should I replace exhaust hose, I am sure its original doesn't appear to be leaking however usual dry-rot cracks visible from a 40 year old exhaust pipe? When I put the new water mixing elbow in should I use any anti-seize compound or pipe dope ectera on threads.
I hope to complete this project on Friday if parts come in and detail what I did with pictures and verbiage so I can post and provide to other members.
Thanks for any and all assistance.
Chris
Hoping someone can point me in the right direction if my below assumptions or plan is not correct. I have searched multiple forums, ran internet searches and read the YANMAR service manual. If anyone has any recommendation or advisory against my methodology any and all encouragement and criticism is welcomed. I look forward to be a contributing member of the board. Thank you in advance.
I only ran her for a 2 minutes and shut her down due to no cooling water being supplied through the engine. I will complete the regular maintenance, ie ,Oil change/filter/filter screen clean, alternator belt, thermostat, fuel filter, racor filter, charge or replace batteries and drain fuel tank in the near future. Main issues I see with the particular YANMAR SB8 are related to cooling and exhaust issues besides already mentioned maintenance above Below are the 3 main issues.
#1The water isn't pumping through block.
#2Calcification in block
#3Rusted and compromised exhaust elbow ie hole
I inspected and completed or planning on the following on her however all 3 of my issues cause me concern about water backflowing into exhaust ports. Is the issue of backflow only at the mixing exhaust tube? If I disconnect the hose from the cooling water outlet to the water mixing elbow do I bypass the chance of water entering ports? After reviewing the schematics of the piping diagram in the service manual this looks like the only interface between H2O and ports, can anyone confirm before I flood my engine? , welcome any input.
#1 Yesterday, I inspected impeller it seemed flexible and intact. I cleaned off old filter material and installed new gasket. I detached intake line from sea cock and cleaned inline sea strainer filter and re-filled strainer with water and thought I primed hose line with enough fresh water. I also ensured all hose clamps were tight and placed hose in 5 gallon bucket of water. Still no uptake of water, took off impeller cover off again and turned her over to be positive it was spinning and impeller didn't detach from hub.
Sounds like air leak or worn impeller to me, any other ideas? If water pump was bad would impeller still spin? I disconnected hose immediately after cooling water pump should water that I primed with just drip or flow past impeller maybe impeller is worn even though still intact and flexible. What product should be applied to new paper filters, is it a specific type of grease? I couldn't pull out old impeller out I tried but was getting to dark. I saw there are expensive pullers but also saw long nose pliers with a 90 degree bend should work. Going with pliers before buying an actual puller. There is no set screw correct?
My Next step this coming Friday was to install new impeller, gasket and replace water supply hoses because they are severely stiff. I had the five gallon bucket originally on the galley floor when I started engine, should I set the 5 gallon bucket on the sink so I can start a siphon to confirm its primed. Cold weather is coming, I noticed a drain cock near bottom of block if I can't get winterizing fluid in there can I just drain the block for the winter and possibly blow air through cooling system to expel any water if I disconnect cooling water tube from the mixing elbow.
#2There is severe calcification and a corroded engine anode. I read about Muriatic acid wash I plan to do a 15 to 1 acid rinse instead of buying a commercially available product.
My plan was to use PPE, proper acid handling precautions, remove thermostat and disconnect rubber hose at cooling water outlet from water mixing elbow and connect it to a bucket or a longer hose that exits boat. I was going to utilize a drill pump to get solution into block, let sit 15mins and flush and capture wash in 5 gallon bucket from the mixing tube hose add baking soda to acidic water to neutralize and dispose. Possibly repeat procedure if need be. Replace anode and thermostat after wash. Does this sound like the right plan, specifically with disconnecting hose from water mixing elbow?
#3 Replace exhaust elbow due to hole and visible smoke in cabin. My local Yanmar dealer told me the part is no longer available I found stainless steel elbow online and ordered that is aftermarket for the SB8. Seems simple enough as long as elbow unscrews from block. I was going to hit with PB rust blaster until part comes in? Any recommendations or pitfalls to avoid when replacing elbow that others experienced. I plan was going to use a big pipe wrench, to heat or not to heat. Should I replace exhaust hose, I am sure its original doesn't appear to be leaking however usual dry-rot cracks visible from a 40 year old exhaust pipe? When I put the new water mixing elbow in should I use any anti-seize compound or pipe dope ectera on threads.
I hope to complete this project on Friday if parts come in and detail what I did with pictures and verbiage so I can post and provide to other members.
Thanks for any and all assistance.
Chris