I have a univesal m18 engine on my catalina 30 that seems to have no power. The tach is not working so I am not able to monitor the rpms. Is there any way of improving the performance without replacing the engine?
slow universal m18 engine
- Thread starter newboatowner
- Start date
- Status
Boy, that's a wide open question--there are so many possible answers. Here are a few possible issues that come to mind:
Speed: what speed through the water are you actually getting? If you're reaching hull speed you won't go any faster regardless of how much power you apply.
Fuel filters: change both to make sure they are not restricting your supply of clean fuel. If they're clogged, the engine will bog down with no power.
Air filter: diesels need a good supply of clean air to run.
Fuel tank: the fuel should be clean (no water, no bacteria, sludge, etc.) Also, the tank must be properly vented.
Injectors/injection pump: if the injectors are dirty or worn you'll get poor starting, rough idling, lots of smoke, and less power than you should. If the injection pump is out of whack you could have low power and a host of other issues.
Transmission: is it slipping? Your engine could be making full power, but perhaps the transmission is slipping and not turning the prop correctly. Check the transmission fluid level as a first step.
Propeller: is it correctly sized, pitched, and clean? A prop covered with barnacles will spin but is very inefficient. An undersized or oversized prop, or one that has the incorrect pitch, will not move the boat at the right speed either.
Hull: is the bottom clean? A bottom fouled with growth or barnacles will sap power and make the boat feel sluggish. Check, and have it cleaned if necessary.
I've got a C-27 with an M-18 diesel in it. The engine has plenty of power and will easily push the boat into the current, headwinds, and waves, without question.
The above is just a quick list of things to check. Let us know what you find.
Randy
Speed: what speed through the water are you actually getting? If you're reaching hull speed you won't go any faster regardless of how much power you apply.
Fuel filters: change both to make sure they are not restricting your supply of clean fuel. If they're clogged, the engine will bog down with no power.
Air filter: diesels need a good supply of clean air to run.
Fuel tank: the fuel should be clean (no water, no bacteria, sludge, etc.) Also, the tank must be properly vented.
Injectors/injection pump: if the injectors are dirty or worn you'll get poor starting, rough idling, lots of smoke, and less power than you should. If the injection pump is out of whack you could have low power and a host of other issues.
Transmission: is it slipping? Your engine could be making full power, but perhaps the transmission is slipping and not turning the prop correctly. Check the transmission fluid level as a first step.
Propeller: is it correctly sized, pitched, and clean? A prop covered with barnacles will spin but is very inefficient. An undersized or oversized prop, or one that has the incorrect pitch, will not move the boat at the right speed either.
Hull: is the bottom clean? A bottom fouled with growth or barnacles will sap power and make the boat feel sluggish. Check, and have it cleaned if necessary.
I've got a C-27 with an M-18 diesel in it. The engine has plenty of power and will easily push the boat into the current, headwinds, and waves, without question.
The above is just a quick list of things to check. Let us know what you find.
Randy
Newboatowner: This topic comes up every now and then. There is nothing wrong with your engine and there is nothing you can do to make it more powerful.
The 18 HP is a great little engine. Unfortunately, it is inadequate for your C30 especially in the conditions you sail in - wind and current. It probably works fine in boats that weigh less than yours. Catalina wanted to convert to diesel from the Atomic 4 (one of the best marine engines ever produced) due to customer demand - diesel is safer than gas - but stopped installing that engine in C30's shortly after it was introduced due to customer complaints of low power.
A C25 that weighs about 4000 lbs is generally powered by a 9.5HP engine. Fully loaded, a C30 weighs over 12,00 lbs so you can see the problem. The rule of thumb, according to Yanmar, is 1 HP for every 500 lbs of boat weigh. That is why the 25XP came into existence.
Know that you now know what you have to deal with from an engine standpoint your sailing life can go on. Your engine is auxilliary power. That means your main power is your sails. In a tough situation, with wind and waves smaking you around, your engine is not your salvation but your sails are. In your case you have to be a better sailor than a motor boat driver.
The 18 HP is a great little engine. Unfortunately, it is inadequate for your C30 especially in the conditions you sail in - wind and current. It probably works fine in boats that weigh less than yours. Catalina wanted to convert to diesel from the Atomic 4 (one of the best marine engines ever produced) due to customer demand - diesel is safer than gas - but stopped installing that engine in C30's shortly after it was introduced due to customer complaints of low power.
A C25 that weighs about 4000 lbs is generally powered by a 9.5HP engine. Fully loaded, a C30 weighs over 12,00 lbs so you can see the problem. The rule of thumb, according to Yanmar, is 1 HP for every 500 lbs of boat weigh. That is why the 25XP came into existence.
Know that you now know what you have to deal with from an engine standpoint your sailing life can go on. Your engine is auxilliary power. That means your main power is your sails. In a tough situation, with wind and waves smaking you around, your engine is not your salvation but your sails are. In your case you have to be a better sailor than a motor boat driver.
I thank both of you for your reply. I did check out the items on the list and found that the transmission fluid was a little low. I topped it off and then discovered that the prior owner failed to secure the transmission cable to the selector with a nut so I replaced it with a nut and bolt. Then I found that the transmission hesitated for a moment to shift into forward. I should add that when I was motoring through a rough area of Plum Gut off Orient Point, NY the engage suddenly cut out after I heard a tremendous bang from the engine area. This transmission does not have a lot of hours on it. Did I blow the tranny?
Possibly, but hopefully just slipped. As for the power, the Model 18 is awesome for my C27 at 7000lbs, but like the first guy said, yours outgrosses mine by around 4000lbs. Just don't expect a lot of thrust out of it.
The boat is located far from my home and I took a ride to try to correct this problem. A tech suggested that I disconnect the transmission cable and try to operate it by throwing the control lever into each gear and see if it engages. I did this and, yes, in fact the transmission went into all gears. I adjusted the cable to shorten it up as much as I could but to no avail. It may be that the cable stretched too much. I cannot get a new one in time to get out of here. The question is can I adjust the lever on the selection shaft to take up some of the slack? It can be loosened and rotated into another position. Is this possible or will this be the kiss of death for this unit?
Newboatowner: Do yourself a favor and purchase a new and correct length shift cable. While you are at it check out the throttle cable and see what condition that is in. There might come a time when you really need the engine to get out of a tight situation and that is exactly when a "mickey mouse jerry rigged" setup will fail.
A few years ago a simple week day trip to the harbor pump station turned into a mess. It was just me and my dog and on the way back to the slip and just before I was to turn into the slip way, where I shift to neutral, I could not get the tranny out of forward. I motored around the turning basin trying to figure out what to do next. I was hoping to bounce off an end tie but all were occupied. I noticed everytime I came head to wind the boat slowed down and since I have a up wind slip I decided to give it a try and it worked. When I checked the tranny the cable end fell apart in my hand. I replaced both the shift and throttle cable.
A few years ago a simple week day trip to the harbor pump station turned into a mess. It was just me and my dog and on the way back to the slip and just before I was to turn into the slip way, where I shift to neutral, I could not get the tranny out of forward. I motored around the turning basin trying to figure out what to do next. I was hoping to bounce off an end tie but all were occupied. I noticed everytime I came head to wind the boat slowed down and since I have a up wind slip I decided to give it a try and it worked. When I checked the tranny the cable end fell apart in my hand. I replaced both the shift and throttle cable.
I did finally get a close look at the cable and it appeared to be in good shape at both ends. I spoke with a tech at one of the suppliers of ZF transmissions and asked if he thought the cable stretched. He told me that it is highly unlikely that it did. I ran my idea of loosening the selector arm and rotating it to a new position and he agreed that this might work. I tried it and so far, so good. I will have to watch it carefully to see if the original problem comes back. Your suggestion of a change of cable may be the final answer, though. Thanks for your imput.
- Status