Boat: '87 Cat 30 with Universal M25 diesel. Unknown hours on engine. When I'm motoring somewhere, I keep the engine at 2000 RPM with gives me around 5 knots (+/-) of speed depending on wind etc. Just curious to see what engine speed others use as a normal RPM setting when motoring??? Thanks. Jim
What's your normal RPM?
- Thread starter JimmyDreams
- Start date
- Status
- Not open for further replies.
J
J. Gilmour
Same, M25 in '94 C270, 350 hrs. stock 2
bladed prop. 'bout as fast as I usually motor unless the Catalina Express is chasing me into port.
bladed prop. 'bout as fast as I usually motor unless the Catalina Express is chasing me into port.
J
Jerry
RPM'S
Comfort Zone likes to run between 1800 and 2300. 2600+ and it gets a little smokey. 2300 puts us at about 6.5 knots on the c28. M3 18 horse.
Comfort Zone likes to run between 1800 and 2300. 2600+ and it gets a little smokey. 2300 puts us at about 6.5 knots on the c28. M3 18 horse.
Run It Hard
As it has been stated before, diesels like to be run hard. The recommendation is 75% - 80$ of maximum RPM's. I have a 1990 Universal 25xp with a maximum RPM of 3300. I run it all day long at between 2600 and 2700 RPM's and maintain 160 degrees. Running a diesel below these recommendations can lead to carbon build up, etc.
As it has been stated before, diesels like to be run hard. The recommendation is 75% - 80$ of maximum RPM's. I have a 1990 Universal 25xp with a maximum RPM of 3300. I run it all day long at between 2600 and 2700 RPM's and maintain 160 degrees. Running a diesel below these recommendations can lead to carbon build up, etc.
Check your Tach?
I agree with Dave. 75-80% of max RPM, all day long. For my '87 M25XP, WOT is 3100, and I cruise at 24-2600. If you can't get at least 3000-3100 at WOT in neutral, check your tach. Most are off. Easy to adjust, but you really don't have to. Find out what WOT is for your engine, then cruise at 75% of that. If you develop soot at 75%, you could have other problems. Injectors could be worn/fouled, or you could be over-propped.
I agree with Dave. 75-80% of max RPM, all day long. For my '87 M25XP, WOT is 3100, and I cruise at 24-2600. If you can't get at least 3000-3100 at WOT in neutral, check your tach. Most are off. Easy to adjust, but you really don't have to. Find out what WOT is for your engine, then cruise at 75% of that. If you develop soot at 75%, you could have other problems. Injectors could be worn/fouled, or you could be over-propped.
Don't know if I agree with
I know Diesel engines like to be ran "under load" maybe that's what Dave meant. But Don't want folks to construe that running at WOT all the time is the thing to do (Dave didn't say to do this but it could be misread). I believe that running the motor in gear at almost any RPM provides load, but I'm not 100% sure. Perhaps someone more qualified can elaborate?
I know Diesel engines like to be ran "under load" maybe that's what Dave meant. But Don't want folks to construe that running at WOT all the time is the thing to do (Dave didn't say to do this but it could be misread). I believe that running the motor in gear at almost any RPM provides load, but I'm not 100% sure. Perhaps someone more qualified can elaborate?
Engine RPM
I repowered our '77 C30 with a Yanmar 2GM which has either 13 or 15 HP depending on who you listen to. The single cylinder YSE-12 died and was not worth rebuilding. The little 2GM at WOT is 3600 RPM and I usually keep it at 2900/3000 which gives me about 4+ knots and at 3200 I am just shy of 5 knots. I have a three blade Campbell Sailor prop and it does not lug the engine down what so ever at any RPM. At 3600 it is just starting to put some black smoke out of the exhaust. Yes the boat is under powered but it was what was available at the time. BTW I have spent 41 night aboard away from our home port since the last weekend of March and planning a 16 day venture in two weeks. Cliff Carter PlusOne C30 #598
I repowered our '77 C30 with a Yanmar 2GM which has either 13 or 15 HP depending on who you listen to. The single cylinder YSE-12 died and was not worth rebuilding. The little 2GM at WOT is 3600 RPM and I usually keep it at 2900/3000 which gives me about 4+ knots and at 3200 I am just shy of 5 knots. I have a three blade Campbell Sailor prop and it does not lug the engine down what so ever at any RPM. At 3600 it is just starting to put some black smoke out of the exhaust. Yes the boat is under powered but it was what was available at the time. BTW I have spent 41 night aboard away from our home port since the last weekend of March and planning a 16 day venture in two weeks. Cliff Carter PlusOne C30 #598
G
Glenn
1500 rpm
I run at 1500 to 2000 max. I motor out only 10 minutes from slip to bay and another 10 minutes to the point where I hoist the sails. There are too many crab traps along the channel to raise sails immediately. My engine is the original 5411 and shows less than 400 hours. This may be right since the boat has been right on Galveston Bay since it was bought new. Since changing the oil in early June and having been out at least 5 times I have added less than 10 hours. Do you think it would be advisable to run at higher rpm's? I have only a slight hint of smoke at start up and only occasionally.
I run at 1500 to 2000 max. I motor out only 10 minutes from slip to bay and another 10 minutes to the point where I hoist the sails. There are too many crab traps along the channel to raise sails immediately. My engine is the original 5411 and shows less than 400 hours. This may be right since the boat has been right on Galveston Bay since it was bought new. Since changing the oil in early June and having been out at least 5 times I have added less than 10 hours. Do you think it would be advisable to run at higher rpm's? I have only a slight hint of smoke at start up and only occasionally.
25-28 normal running
34-36 wide open. I was told to run her hard and for atleast 30 minutes to avoid buildup. I was also told by a reputable surveyor that running her wide open all day wouldnt hurt her at all. it just doesnt make sense to do so because the extra knot or so you get isnt fuel efficent.
34-36 wide open. I was told to run her hard and for atleast 30 minutes to avoid buildup. I was also told by a reputable surveyor that running her wide open all day wouldnt hurt her at all. it just doesnt make sense to do so because the extra knot or so you get isnt fuel efficent.
- Status
- Not open for further replies.