Well, we spent about 11 hours yesterday for our survey and sea-trial. Now I have more questions.;-) Overall, the results were good. The boat is a 1990 model, hull #6 I'm told. The main issues that came out of the survey are as follows: 1. The bottom paint is coming off in large areas and has water trapped under it in many places. The owner had the bottom done about a year ago, so of course he was surprised to hear this. Upon talking to the local Hunter dealer we were told that it probably was due to improper preparation before initial painting. The Hunter shop says that the factory recommeded that you use an etching agent prior to bottom paint and advised not to sand the bottom. Something about the type of resin used in the gelcoat. It appears that whoever did the initial bottom job applied a green colored material to the bare hull to attempt to give the surface some teeth. Anyone, had any experience similar to this? 2. The yanmar overheated after about 15 minutes of running at full throttle. The engine only has about 1200 hours on it. When the throttle was reduced to 2000 rpms the temp came right down and stayed there. The Hunter shop says that this behavior is not unusual for the P42. There is also a maxprop installed and the surveyor said it should be adjusted because we were only able to turn up to 3150 rpms. What should this engine turn? The Hunter shop says that the P42 is actually overpowered and that since you actually reach hull speed well below full throttle, increasing it beyond that could also help cause the overheating. Any thoughts would certainly be appreciated. 3. Finally, when the surveyor unearthed the holding tank it had a lot of caulk on the exterior of the tank. He then stuck his finger through the wall of the tank. It has to come out. Does anyone know what size the holding tank is? Also, what has been the success of replacing the alum tank with the poly tanks everyone is recommending? I spoke with Peggy briefly today. For those of you lucky guys who have already replaced yours, what did you replace it with? The one in our boat is in the right center of the saloon, I assume that is where it was originally. Have any of you installed them differently than the original install? Peggy recommends going with multiple holding tanks? Anyone done that? That is the majors, other than these the rest are relatively minor. Any experience on any of these would certainly be appreciated. Steve
- Status
AS to the engine . . .
What engine does it have? We have the 62 HP turbo on ours. Hull #206. It cruises at 3000 rpm, which is about 80% of wide open. You should try to cruise at 80% of wide open and wide open must be at least 3600 If you cannot reach 3600 then your propeller is too big or has too much pitch and should be adjusted. I think these rpm figures are the same for turbo and non-turbo 4 cylinder engines. If it cant reach these rpms you will get black smoke and will hurt your engine. Our engine will overheat if we run it wide open, too. But you are never supposed to run it wide open!!! About once a month we run at 3400 rpm for about an hour to burn out carbon and it does not over heat at that speed. But never run at full throttle except for testing and short speed needs. also, check your seawater impeller and make sure it has all if its paddles and check you heat exchanger and make sure no old broken paddles are blocking the way. Your antifreeze mix is important too. It must be 50/50, whcih allows the engine to run hoter without overheating. Also check the rating of the pressure cap on the antifreeze fill port and replace it. The pressure cap allows for hotter running without overheating but the caps wear out and need replacing every 4 or 5 years or so. We run at just below hull speed at 3000. Our prop is a little small, 17x15 two blade folding, because we want as little interference with sailing as possible. with a clean bottom we cruise at 7.8 kts at 3000.
What engine does it have? We have the 62 HP turbo on ours. Hull #206. It cruises at 3000 rpm, which is about 80% of wide open. You should try to cruise at 80% of wide open and wide open must be at least 3600 If you cannot reach 3600 then your propeller is too big or has too much pitch and should be adjusted. I think these rpm figures are the same for turbo and non-turbo 4 cylinder engines. If it cant reach these rpms you will get black smoke and will hurt your engine. Our engine will overheat if we run it wide open, too. But you are never supposed to run it wide open!!! About once a month we run at 3400 rpm for about an hour to burn out carbon and it does not over heat at that speed. But never run at full throttle except for testing and short speed needs. also, check your seawater impeller and make sure it has all if its paddles and check you heat exchanger and make sure no old broken paddles are blocking the way. Your antifreeze mix is important too. It must be 50/50, whcih allows the engine to run hoter without overheating. Also check the rating of the pressure cap on the antifreeze fill port and replace it. The pressure cap allows for hotter running without overheating but the caps wear out and need replacing every 4 or 5 years or so. We run at just below hull speed at 3000. Our prop is a little small, 17x15 two blade folding, because we want as little interference with sailing as possible. with a clean bottom we cruise at 7.8 kts at 3000.
2 Cents Worth
I would remove all the bottom paint and redo the bottom the right way. As long as there are no blisters you are ok. I also had to remove the holding tank on our 91 42. This is the 3 holding tank the boat has had. Why the 42 has a problem with the holding tanks is beyound me. The second tank was a stainless tank. Don't know about finding a plastic tank that will fit. I did replace it with a 35 gallon tank that the newer boats came with. Heres what I did to replace the tank. !. Remove the tank. You will have to remove as much as you can from the tank before starting. Also you may have to use a crowbar to get it out. 2. Clean out the old foam. 3. Check that the new tank and hoses fit. 4. Spray in new foam. 5. Install new tank. 6. Hook up new hoses. My old tank had over flowed which made the job not much fun.
I would remove all the bottom paint and redo the bottom the right way. As long as there are no blisters you are ok. I also had to remove the holding tank on our 91 42. This is the 3 holding tank the boat has had. Why the 42 has a problem with the holding tanks is beyound me. The second tank was a stainless tank. Don't know about finding a plastic tank that will fit. I did replace it with a 35 gallon tank that the newer boats came with. Heres what I did to replace the tank. !. Remove the tank. You will have to remove as much as you can from the tank before starting. Also you may have to use a crowbar to get it out. 2. Clean out the old foam. 3. Check that the new tank and hoses fit. 4. Spray in new foam. 5. Install new tank. 6. Hook up new hoses. My old tank had over flowed which made the job not much fun.
Thanks for the info. Bill, the surveyor scratched around in several of the locations in question. He said that they were not blisters, just paint that was no longer adhering to the fiberglass. He only found 2 blisters on the entire hull, each about the size of a nickel on the keel stub. He was very pleased with that,especially with a ten year old boat. I think that I should be able to find a poly holding tank for the area in question. I was just curious if anyone had relocated it or installed a second one as Peggy suggested. And Brad, the engine is the original yanmar, non-turbo 62 HP, with about 1200 hours on it. It has a maxprop on it and would only allow it to turn up to about 3150 rpms. I understand that it is restricting the engine from developing it's full power, but fail to see how that should cause it to overheat. I agree that the prop needs to be adjusted to allow the engine to deliver the recommended rpms, but think that it would overheat even quicker if it were developing more HP. When we powered back down to around 2500 rpms the temp came back down and stayed there. It may just be a normal characteristic of the installation. Thanks for your insight and assistance gentlemen, Steve
Holding tank
We should be able to supply a tank...but I'd like to elaborate a little on why, when you called yesterday, I recommended going with two tanks instead of only replacing the one: The boat has two heads--one forward and one aft...on a 42' boat, that means that the plumbing run from at least one head--and maybe both--has to be much longer than anyone is ever gonna keep pumping to move bowl contents all the way from the head to the tank. We don't recommend a head discharge hose longer than 10'...and that's being generous, 'cuz field tests over the years have shown that nobody pumps a toilet (or leaves their finger on the button) longer than it takes to move bowl contents a maximum of 6'...most people stop pumping as soon as the bowl is empty. Since the stuff only keeps moving as long as somebody is moving it, that means sewage is gonna just sit in the hose till the head is flushed again...moved a little further to sit till the next time..etc. Sewage left sitting in hoses permeates hoses...and permeated hoses make the boat stink. Boat builders are beginning to catch on to this, and later models now have two tanks, closer to the heads...but it's not at all uncommon to find just one tank, buried under the cabin sole, in boats that are 10 yrs old or older. They're just catching onto a few other issues too...installing sumps instead of letting iceboxes and refrigerators just drain into the bilge, etc...so you may find that installing two tanks (or maybe a Lectra/San on one head and a tank on the other one) isn't the only modification you'll want to make. But updating and upgrading is half the fun of buying an older boat...plus, when you own an older boat, you will never have to complain, "I don't have anything to do."
Congratulations on a fine choice...Give me another call when the dust settles after the purchase and we'll sort out the best way to solve your holding tank and any other plumbing problems.
We should be able to supply a tank...but I'd like to elaborate a little on why, when you called yesterday, I recommended going with two tanks instead of only replacing the one: The boat has two heads--one forward and one aft...on a 42' boat, that means that the plumbing run from at least one head--and maybe both--has to be much longer than anyone is ever gonna keep pumping to move bowl contents all the way from the head to the tank. We don't recommend a head discharge hose longer than 10'...and that's being generous, 'cuz field tests over the years have shown that nobody pumps a toilet (or leaves their finger on the button) longer than it takes to move bowl contents a maximum of 6'...most people stop pumping as soon as the bowl is empty. Since the stuff only keeps moving as long as somebody is moving it, that means sewage is gonna just sit in the hose till the head is flushed again...moved a little further to sit till the next time..etc. Sewage left sitting in hoses permeates hoses...and permeated hoses make the boat stink. Boat builders are beginning to catch on to this, and later models now have two tanks, closer to the heads...but it's not at all uncommon to find just one tank, buried under the cabin sole, in boats that are 10 yrs old or older. They're just catching onto a few other issues too...installing sumps instead of letting iceboxes and refrigerators just drain into the bilge, etc...so you may find that installing two tanks (or maybe a Lectra/San on one head and a tank on the other one) isn't the only modification you'll want to make. But updating and upgrading is half the fun of buying an older boat...plus, when you own an older boat, you will never have to complain, "I don't have anything to do."
Congratulations on a fine choice...Give me another call when the dust settles after the purchase and we'll sort out the best way to solve your holding tank and any other plumbing problems.Overheating, Brads response.
Steve: In regard to Brads response regarding overheating. Regardless of the ACTUAL rpm's, the engine is maxed out. It is the fact that you are putting the maximum load on the engine. It is kinda like your car. On the flats it will go 125mph in 5th gear. Try doing 125 up a hill in 5th gear, it won't do it. This is the only analogy that I can come up with. Remember that these engines must be able to rev to the max rpm out of gear as well as in gear. If you cannot rev to max (3600) out of gear there is something wrong with the engine, usually the govenor or the mixing elbow but can be pumps, injectors etc too. Then when we add the load of the prop we are then testing the prop (kinda like the 5th gear thing) load. We must be able to push the engine to 3600 rpm here again. Then when we run the engine at 80% we are going to get our max HP and cooling that the engine is designed for. I do not know if this makes it easier to understand or not.
Steve: In regard to Brads response regarding overheating. Regardless of the ACTUAL rpm's, the engine is maxed out. It is the fact that you are putting the maximum load on the engine. It is kinda like your car. On the flats it will go 125mph in 5th gear. Try doing 125 up a hill in 5th gear, it won't do it. This is the only analogy that I can come up with. Remember that these engines must be able to rev to the max rpm out of gear as well as in gear. If you cannot rev to max (3600) out of gear there is something wrong with the engine, usually the govenor or the mixing elbow but can be pumps, injectors etc too. Then when we add the load of the prop we are then testing the prop (kinda like the 5th gear thing) load. We must be able to push the engine to 3600 rpm here again. Then when we run the engine at 80% we are going to get our max HP and cooling that the engine is designed for. I do not know if this makes it easier to understand or not.
Brad? Are you saying...
...that the engine will overheat at max rpm under load and that it really shouldn't be run above 80% when under load? Please clarify.
...that the engine will overheat at max rpm under load and that it really shouldn't be run above 80% when under load? Please clarify.
Paul, Steve Dion is right
He is saying you cruise at 80% of max rpm under load, usually about 2900 to 3100. And that max MUST be at least 3600 rpm. 3700 is OK but 3500 is not. So, adjust the pitch on the feathering prop. Steve makes a good point on the "out of gear" rpm. slowly rev the engine up out of gear and make sure it will reach 3600. It should go to 4000 but dont take it there! stop at 3600 to 3800. Once your pitch is correct, about once a month run it at 3400 under load for about an hour to really heat it up and burn the carbon out of the system. It should not overheat at 3400. If it does, you have some sort of problem like I mentioned in my first post. Remember, these engines should be always under load within about 5 minutes after turning it on. Don't let it sit and idle and dont use it to make electricity or hot water at anchor. I hope you have a generator instead. You should look for a Yanmar class and take it. I took one in Deltaville by the very knowledgable Craig Beechler and even though I retained only about 20% of what he taught, it is 20% more than I knew and has really helped me to understand the engineering of the diesel system.
He is saying you cruise at 80% of max rpm under load, usually about 2900 to 3100. And that max MUST be at least 3600 rpm. 3700 is OK but 3500 is not. So, adjust the pitch on the feathering prop. Steve makes a good point on the "out of gear" rpm. slowly rev the engine up out of gear and make sure it will reach 3600. It should go to 4000 but dont take it there! stop at 3600 to 3800. Once your pitch is correct, about once a month run it at 3400 under load for about an hour to really heat it up and burn the carbon out of the system. It should not overheat at 3400. If it does, you have some sort of problem like I mentioned in my first post. Remember, these engines should be always under load within about 5 minutes after turning it on. Don't let it sit and idle and dont use it to make electricity or hot water at anchor. I hope you have a generator instead. You should look for a Yanmar class and take it. I took one in Deltaville by the very knowledgable Craig Beechler and even though I retained only about 20% of what he taught, it is 20% more than I knew and has really helped me to understand the engineering of the diesel system.
80% is the magic number
Diesels should never be run at maximum RPM for hours. Short periods of time to blow them out is OK. The previous post was correct in that you should be able to get just about as many RPMS with the boat in neutral as you do in forward. If you can't there is something wrong. Wrong prop, injectors, mixing elbow or something else. The Yanmars love to run at higher RPM and it's good for them. 80% of maximum RPM is the "rule of thumb" for long periods of time. Running at full throttle for 15 minutes or so should not cause the engine to overhead. You may see some black smoke, but that's OK, it's just unburned fuel. By the way, never rev up your turbo diesel then shut it off. Let it idle for a minute or so so the turbo has a chance to slow down while still being lubricated. It spins at very high RPM's and needs oil to cool it. Once the engine is shut off the oil stops but the turbo is still spinning if the boat is reved up before shut down. Mark Johnson
Diesels should never be run at maximum RPM for hours. Short periods of time to blow them out is OK. The previous post was correct in that you should be able to get just about as many RPMS with the boat in neutral as you do in forward. If you can't there is something wrong. Wrong prop, injectors, mixing elbow or something else. The Yanmars love to run at higher RPM and it's good for them. 80% of maximum RPM is the "rule of thumb" for long periods of time. Running at full throttle for 15 minutes or so should not cause the engine to overhead. You may see some black smoke, but that's OK, it's just unburned fuel. By the way, never rev up your turbo diesel then shut it off. Let it idle for a minute or so so the turbo has a chance to slow down while still being lubricated. It spins at very high RPM's and needs oil to cool it. Once the engine is shut off the oil stops but the turbo is still spinning if the boat is reved up before shut down. Mark Johnson
Howdy Ho Paul A.
As Brad stated, You should be able run your engine at 3400 rpms for upto an hour without overheating. The NORMAL operating range is 70-80% of the max rating (3600) this equates to 2500 - 2900. All of these numbers assume that the engine will rev to 3600 in neutral. If it will not then we have to look at other things. Operating your engine below the 2500 saves fuel but causes the engine run less efficent and less cooling. Operating above this range probably wastes fuel and causes the engine to run warmer. Normally you do not need to run above the 80% threshold unless you have the WRONG prop or you are running against a current. I have been told that these engines (when properly maintained) will run for 12,000 - 15,000 hours. Be sure to have your valves adjusted every 500 hours. I think you will see some recent posts that refer to hard starting when cold. These problems were corrected with a simple valve adjustment. Change the oil and all the filters EVERY season. Keep your fuel clean. Always add biocide to your fuel. Change your belts every two to three years. Take care of your Yanmar and it will take care of you. Take a look at the maintenance schedules on German cars, they are very similar schedules. They change these things on regular cycles not when they break. I can tell you that I have had a few of these vehicles and they will last if you take care of them.
As Brad stated, You should be able run your engine at 3400 rpms for upto an hour without overheating. The NORMAL operating range is 70-80% of the max rating (3600) this equates to 2500 - 2900. All of these numbers assume that the engine will rev to 3600 in neutral. If it will not then we have to look at other things. Operating your engine below the 2500 saves fuel but causes the engine run less efficent and less cooling. Operating above this range probably wastes fuel and causes the engine to run warmer. Normally you do not need to run above the 80% threshold unless you have the WRONG prop or you are running against a current. I have been told that these engines (when properly maintained) will run for 12,000 - 15,000 hours. Be sure to have your valves adjusted every 500 hours. I think you will see some recent posts that refer to hard starting when cold. These problems were corrected with a simple valve adjustment. Change the oil and all the filters EVERY season. Keep your fuel clean. Always add biocide to your fuel. Change your belts every two to three years. Take care of your Yanmar and it will take care of you. Take a look at the maintenance schedules on German cars, they are very similar schedules. They change these things on regular cycles not when they break. I can tell you that I have had a few of these vehicles and they will last if you take care of them.
Thanks Steve
Thanks, Steve: The reason I asked, is that I once ran full throttle for a few minutes on the advice of a reputable mechanic. It overheated after about 15 - 20 minutes. I may have misunderstood him because he said I should achieve full rpm if the prop was tuned to the engine properly. He also said that I should "blow it out" periodically. These two recommendations may have been misunderstood. Subsequently, I have been gun shy to run in the higher RPM range of this engine (3HM35F - 3200rpm). I often stay around 2300-2400rpm, but I guess I can go to 2500-2600 comfortably. I'll have to try that next season when I get it out of winter mothballs. Thanks again.
Thanks, Steve: The reason I asked, is that I once ran full throttle for a few minutes on the advice of a reputable mechanic. It overheated after about 15 - 20 minutes. I may have misunderstood him because he said I should achieve full rpm if the prop was tuned to the engine properly. He also said that I should "blow it out" periodically. These two recommendations may have been misunderstood. Subsequently, I have been gun shy to run in the higher RPM range of this engine (3HM35F - 3200rpm). I often stay around 2300-2400rpm, but I guess I can go to 2500-2600 comfortably. I'll have to try that next season when I get it out of winter mothballs. Thanks again.
Paul et al.
I understand needing a job and having to work for a living but have you thought about moving to an area where moth balling the fleet is a thing of the past? We also live in snow country (Carson City, NV), but our boat is located in the Sacramento Delta from the San Francisco bay area(about 65 miles over the water) . We have the pleasure of having the ability to sail year round (weather permitting). In the winter we trek over the hill like Snow Shoe Johnson but we use the car. It is about 170 miles from the house to the marina. We use the boat like a condo. This is a great time of the year to get these projects done that *I* put off all summer because I like to play. Remember take care of your Yanmar! Happy Holidays.
I understand needing a job and having to work for a living but have you thought about moving to an area where moth balling the fleet is a thing of the past? We also live in snow country (Carson City, NV), but our boat is located in the Sacramento Delta from the San Francisco bay area(about 65 miles over the water) . We have the pleasure of having the ability to sail year round (weather permitting). In the winter we trek over the hill like Snow Shoe Johnson but we use the car. It is about 170 miles from the house to the marina. We use the boat like a condo. This is a great time of the year to get these projects done that *I* put off all summer because I like to play. Remember take care of your Yanmar! Happy Holidays.
Change the Pitch
I think that your pitch is off. You must have it set so the engine can turn 3600 rpm or so under way. If not, the additional fuel is lugging the engine and causing the heating. This will lead to bigger problems in the future. Also, put in a new impeller if over a year old.
I think that your pitch is off. You must have it set so the engine can turn 3600 rpm or so under way. If not, the additional fuel is lugging the engine and causing the heating. This will lead to bigger problems in the future. Also, put in a new impeller if over a year old.
Well everyone, As expected the answers were to be found here. I have also spoken to a couple of mechanics in other yards(without any interest in the sale of the boat one way or another) and all are confirming what you have said here. 1. I need to adjust the pitch on the max-prop to get the rpms up to around 3600. Most have said that will probably take care of overheating alone. However, it seems as mentioned here the mixing elbow would be the first suspect if there is still a problem after adjusting the prop. It seems that most of the diesel mechanics all say the same thing. We should run these things harder than most of us do and the engine would thank us in the long run. 2. The holding tank issue is just one for Peggy and I to work out the details of after closing. I don't know about putting in separate tanks on the 42. Given the locations of everything else, I'm not sure where you could mount separate tanks. I don't think I want to totally redesign the whole boat layout. 3. The bottom issue is also resolved, I suppose. I talked to the local Hunter shop manager and he again confirmed what someone else had said earlier. He also stated that it is still a problem today with the Hunters. The 5 year warranty is voided if you sand the bottom at all to allow the paint to adhere to the bottom. They use a method called skip-sand that is applied to the bottom to give some tooth so the paint will stick. Jeff, the shop manager, told me that they still do it the same way today, but they still get problem occasionally themselves. His recommendation is to remove all existing paint, skip sand any areas where it is missing, then 4 coats epoxy barrier coating, followed by a bottom paint. Anyway, all that said, we are going back to the owner for a reduction for the bottom and holding tank and hope to close this thing before Christmas. On another note any Hunter owners in the Tampa Bay area? We would like to move the boat to the Clearwater/Dunedin area if a slip opens up. Wonder if any of you guys have any opinions on marinas in the area? Thanks again for all the help and info to all who contributed. I have been away from sailing for a long time and am sure I will be able to bother you all with more questions in the future. This board is a tremendous asset to the Hunter owners out there I would like to applaud the efforts of all involved. Steve Watford
Who do you thank?
Steve: The real thanks goes to Bly & Phil for funding this thing out of their pockets. The members of HOW all get to share equally with questions and responses in their learning process.
Steve: The real thanks goes to Bly & Phil for funding this thing out of their pockets. The members of HOW all get to share equally with questions and responses in their learning process.
I did multiple tanks
I added a second, mirror-image tank (same material as the first one - it was fabricated by Hunter). It was placed under the dinette table. The table would not lower, but i wanted the tank more than I wated an adjustable table. We ran the for'd head to the new tank, which was also equiped with its own pumpout and macerator. The original tank, its pumpout and macerator were connected to the adft head. Worked great - dpoubled my holding capacity. I did not have any problems with the materials, although I did develop an unresolved problem with the forward head after 3.5 years. I'm trying to remember the exact problem (too much CRT radiation in my brain); I think the head would fill the bowl and overflow even when valves were closed.
I added a second, mirror-image tank (same material as the first one - it was fabricated by Hunter). It was placed under the dinette table. The table would not lower, but i wanted the tank more than I wated an adjustable table. We ran the for'd head to the new tank, which was also equiped with its own pumpout and macerator. The original tank, its pumpout and macerator were connected to the adft head. Worked great - dpoubled my holding capacity. I did not have any problems with the materials, although I did develop an unresolved problem with the forward head after 3.5 years. I'm trying to remember the exact problem (too much CRT radiation in my brain); I think the head would fill the bowl and overflow even when valves were closed.
Second Tank
Adding a 2nd tank under the table would still give you the problem of being to far away from the head. I don't know where you could put in a 2nd tank that would be closer unless it was at the bottom of one of the deep lockers. One thing I think that may help the aft head flush better is to put in another thru hull closer to the head. That way you would not have to pump the water so far to flush. Does anyone know what is under the hanging locker just aft of the back head?
Adding a 2nd tank under the table would still give you the problem of being to far away from the head. I don't know where you could put in a 2nd tank that would be closer unless it was at the bottom of one of the deep lockers. One thing I think that may help the aft head flush better is to put in another thru hull closer to the head. That way you would not have to pump the water so far to flush. Does anyone know what is under the hanging locker just aft of the back head?
- Status