Boat trouble ruins the weekend

[Manipulator]

Well after driving 3 ½ hours to my boat, taking off the top, icing down the beer and lathering up the sunscreen the damn thing is a loss for power. First let me tell you what I have, what I have done, and then the symptoms. It’s a 1983 Sea Ray SR2250 cuddy. It has a 5.7 GM mated to an OMC. Here is a little history. The boat has 750 of papered hours on it. The lower unit was rebuilt about 200 hours ago. I have had the boat two seasons and have changed the oil and lower and upper unit gear lube regularly. This spring I rebuilt the carburetor (4 barrel Q-Jet), I replaced the points, condenser, rotor and cap. I replaced the spark plugs, I replaced the lower and upper fuel filters and cleaned the flame arrest. I set the dwell and timing. First weekend in the lake Dad takes her off the trailer and the thing has no power just like now. He comes back and we take a look and I have two spark plug wires flipped. We flip them and go for a spin and it runs great and has plenty of power. We run all weekend with no problems and she runs great. I come down the following weekend and it again runs great all weekend without any problems. <br /><br />I come down this weekend and it has a loss for power. I could keep it on a plane at 2800 rpm and now it takes 3400 to maintain a slow plane. I punch it wide open and it won’t get my speedo over 20 mph. WOT I could do 35 mph on the speedo last time (probably 5 mph off as I know she will do 40 mph at WOT). I can get the engine rpm up to 4000 rpm but there is no gusto to go with it. Before I could get it to 4200 rpm and it had plenty of punch. The guy that had the boat before got a prop designed more for economy than performance. I believe the rpm range is 4200-4800 for this engine. Anyway, it ran great a few weekends ago. Here is what I have done so far. I checked the lower unit for any prop damage. It did have some lake crud growing on it so I cleaned it all off. There is no visible damage to the prop or lower unit. Besides I don’t remember hitting anything to caused damage. I checked both fuel filters and they are both fine and there is no water in the system. I checked the carb and its getting plenty of fuel, I checked the distributor and rechecked the points, they are like new and I checked the gap and its fine. I went and bought all new spark plug wires and installed them. Went for a test drive and its doing the same thing (lack of power). I checked the timing and it’s right on. I checked to make sure the distributor is advancing and it is. I have checked out the fuel system except the fuel pressure but the carb seems to be getting plenty of fuel and the engine does not act like it is starved for fuel. I checked the ignition and it all checks out. I am at a loss to how this thing can go from running great one weekend to a major lack of power the next. It revs up great without any problems. Even under load it seems to run fine but there just is no power. It idles flawlessly and starts right off with no problems. Any thoughts? What about the coil, could it be bad? What about the lower unit, is there a clutch or something that may be slipping? What am I missing here? Well I couldn’t fix it so we came home. What a bummer! Oh yeah, there seems to be some vibration in the boat at 1800-2500 rpm.

 

[KaGee]

Re: Boat trouble ruins the weekend

I do not recall you mentioning the prop. Have you considered that the hub may be going??

 

[Manipulator]

Re: Boat trouble ruins the weekend

Thanks for the reply Keith. I'm a newbie and really don't know what to look for as far as the hub. I did spin the prop a few times after I cleaned it to look for damage and it spun fine. Would a bad hub cause these symptoms?

 

[novicetech]

Re: Boat trouble ruins the weekend

With a bad hub, it would probably overrev, wgen you put the hammer down.

 

[KaGee]

Re: Boat trouble ruins the weekend

A "spun" prop means that the rubber bushing that isolates the prop shaft from the actual prop is worn, allowing the prop shaft to spin, but not transfering the power to the prop. So, shaft spins, prop, under load, does not spin proportionately, hence the term "spun prop". RPMS from the engine are not being transferred to the propeller.<br /><br />The only fix is to have the prop reconditioned or replaced.

 

[recess]

Re: Boat trouble ruins the weekend

Check your wiring again. The problem sounds like your orginial problem and the only thing you didnt change/check was the wiring. Is it possible someone is switching the wires while your are gone? Just had that happen to my daughters VW. Couldn/t figure out why it wouldn't run. Someone popped the lid and swapped 2 wires around. Kids!!!!!!!!!!!!!!!!!!!!

 

[Manipulator]

Re: Boat trouble ruins the weekend

Thanks again. I was reading on another thread about exhaust flappers. Does the OMC 800 series have those. There was someone who had a stuck one that was having the same trouble I am having. What about temperature? Would that cause engine temp to go up? My gauges are all within normal limits.<br /><br />As far as the "spun prop" issue. What happens? Will the prop get to the point it no longer spins? I wondering if that is the issue, if I have enough left to drive it 5 miles on water to the marina.

 

[Manipulator]

Re: Boat trouble ruins the weekend

Recess, thanks for your reply. This is an excellent question and a question my father and I pondered. Next to my marina is a boat repair shop. The guy there is a total scammer and at one point performed a tune-up on my boat by accident. There was someone who requested a tune-up that had the exact same boat as mine and the other boat owner’s keys fit my boat. He mistook my boat for the other guys. Anyway, I told the gentleman I would be happy to pay for his parts but wasn’t paying for labor, as my boat did not need a tune-up at the time. He actually argued with me over this and then also said he rebuilt my carburetor too. I looked and it was never touched. He told me he would put my old parts back on and the carburetor rebuild would be for free. Basically he changed the rotor cap and points and then the dummy never set the timing so I then had to do it. Anyway, he tried to charge me $400 for parts. I checked on this site and the tune up kit was around $30 and I told him I would pay $60. I could not believe it. I got in an argument with him and basically told him to go F himself and to stay away from my boat. I never paid him anything as he lied about what he did and then lied about the parts cost. Well my boat is always at the lake so this joker might want to get even with me. There is more to the story but we were thinking what you were. It wouldn’t surprise me if this guy goes around and fiddles with boats to drum up business. He has earned a horrible reputation and deserving so. Anyway, I installed new wires today and checked everything and they are all hooked up right. My father thinks it could be a weak spark and thought it could be the coil. He told me to pull each wire one by one while the engine is running and look for a change in idle. He also asked me to try to look at the spark and see if it looked weak. I didn’t do this as its is super busy at the lake this weekend and the boat is just bouncing around in the boat slip. Hard to work when you are bouncing around.

 

[Boomyal]

Re: Boat trouble ruins the weekend

At least some of the OMC stringers have flappers in the intermediate housing. Most likely the Hydro Mech and Mech units. I saw one at the shop with the flapper just hanging, partly attached, I suppose this could cause a proplem if it/they became detached.

 

[waterone1@aol.com]

Re: Boat trouble ruins the weekend

Ok, If I am reading your post correctly, you are able to get 4000 rpm's out of the engine, but boat is not going anywhere. Stop thinking about the engine. Someone else said you might have a spun prop hub. Either raise the drive or pull the boat and put a marker or fingernail polish line across the rubber prop hub and metal prop. Run boat in water, pull boat and see if line is still lined up, if not....prop is spinning on hub. Second thought, make sure drive is going all the way down and not obstructed by tree limb or other problem causing drive to stay too far up. You said that you had some vibration between 1800 -2500 rpms, is there a chance you have a bent prop ? Vibrations can certainly indicate a damaged prop.

 

[Olds Eddie]

Re: Boat trouble ruins the weekend

You mentioned that the outdrive had crud on it. How clean is the bottom. A dirty bottom will greatly affect the performance.

 

[sea wolf]

Re: Boat trouble ruins the weekend

If u have a spare prop, change it out & see what happens. Could it be possible that the guy u had a problem with may have dumped something into your gas tank? Add some fresh fuel to the tank. Have u changed the dist. cap? And I would put a lock on the engine compartment & get a locking gas cap. You never know.

 

[QC]

Re: Boat trouble ruins the weekend

I am with Olds Eddie on this one. If the prop had growth on it, so does the bottom . . . How long did it sit?<br /><br />The key is in the fact that it takes more RPM to plane. The same RPM should get the same speed unless there is more load (bottom condition or more stuff on board or both which is what I suspect) or the prop is spinning or damaged. I don't believe it is damaged unless you hit something you don't remember and I read here that you have looked at it. I don't believe it is spinning or you would have got more RPM at WOT not less. My .02.

 

[Manipulator]

Re: Boat trouble ruins the weekend

Originally posted by waterone1:<br /> Ok, If I am reading your post correctly, you are able to get 4000 rpm's out of the engine, but boat is not going anywhere. Stop thinking about the engine. Someone else said you might have a spun prop hub. Either raise the drive or pull the boat and put a marker or fingernail polish line across the rubber prop hub and metal prop. Run boat in water, pull boat and see if line is still lined up, if not....prop is spinning on hub. Second thought, make sure drive is going all the way down and not obstructed by tree limb or other problem causing drive to stay too far up. You said that you had some vibration between 1800 -2500 rpms, is there a chance you have a bent prop ? Vibrations can certainly indicate a damaged prop.

Yeah, Steering away from the engine as it seems to be running fine. Again, what about the coil? Is it possible that could be the culprit? That is one thing I have not checked. There was a lot of crud covering the prop and after I cleaned it the vibration was less. It has always had a slight vibration but this was more than usual. I ran the drive up and down a few times checking it. It clunks into place. I didn’t see any obstruction. I would like to try the hub trick you mention. The thing is the boat is 3 ½ hours from home so its not something I can just run out and do right away. I will have to bite the bullet and let a mechanic look at it. I want to narrow the search for him so he does have to go through everything all over again. As far as a bent prop, I don’t think it is, as it looks fine. I drive cautiously and keep a look out for debris. The lake I go to very seldom has any tree branches or anything floating around in it. I understand your thinking. Then again let me give you more history. My dad had the boat before me. Two seasons ago he was putting it on the trailer and damaged the lower unit. The guy did not have the trailer in the lake far enough and the skag hit the gravel at the end of the boat ramp. The prop spun into the gravel and possibly the concrete of the boat ramp. The skag was damaged; bent slightly and a small piece broke off the bottom. The prop got a little chewed up but no major damage. The marina bent the skag back and I filed down the missing piece where the skag broke (about 1cm x 1cm piece). I also filed down the imperfections in the prop. It is SS and the marina said it looked fine and just needed to file out the imperfections. Then again this was the same idiot I had the problem with later down the line. Honestly, I don’t think the guy has a mechanics license and just learned from his father who use to own the business. Now that you picked my brain, the vibration started then. Maybe the prop is slightly bent and with time it has screwed the hub up due to abnormal wear. I used the boat the last two seasons but never had this problem that I am having now. Maybe it has just caught up to me. Again, I looked at the prop before and it doesn’t look bent but maybe it can’t be seen with the naked eye. <br /><br />

Originally posted by Olds Eddie:<br /> You mentioned that the outdrive had crud on it. How clean is the bottom. A dirty bottom will greatly affect the performance.

Good question and one I pondered as well. The boat has been in the lake for a month and it does have growth on the bottom (fresh water growth). It has growth but not overwhelming. I had growth worse on it last season and it still drove fine and had plenty of power. <br /><br />

Originally posted by sea wolf:<br /> If u have a spare prop, change it out & see what happens. Could it be possible that the guy u had a problem with may have dumped something into your gas tank? Add some fresh fuel to the tank. Have u changed the dist. cap? And I would put a lock on the engine compartment & get a locking gas cap. You never know.

I do not have another prop. It is possible this joker put something in the tank. I had about a ¼ tank when this started. I filled it up (70 gallon tank) and ran it in the bay for a half hour. It did not seem to make a difference. I also checked the filters and they are fine and were replaced about 200 hour ago. There was no water in the system either. The points, condenser, rotor and cap were replaced 200 hours ago as well. I checked it out and it still looks like knew. I also checked the gap and checked the timing and it is right on. I also checked to see if the distributor is advancing and it is. I just installed new wires and it made no difference except it starts with just a flick of the key. <br /><br />

Originally posted by Quietcat:<br /> I am with Olds Eddie on this one. If the prop had growth on it, so does the bottom . . . How long did it sit?<br /><br />The key is in the fact that it takes more RPM to plane. The same RPM should get the same speed unless there is more load (bottom condition or more stuff on board or both which is what I suspect) or the prop is spinning or damaged. I don't believe it is damaged unless you hit something you don't remember and I read here that you have looked at it. I don't believe it is spinning or you would have got more RPM at WOT not less. My .02.

Again, it sat for a month and it does have growth. Again, it has had more growth in the past and it still had plenty of get up and go. Again, I have not hit anything I’m aware of. There was a few times when I was making a few turns where I heard a quick increase in rpm like the prop came out of the water. I had the trim all the way down and have never experienced something like that before. I thought perhaps I went over a few waves when I turned and thought that may have caused this but I wasn’t going fast at all as it won’t go fast. This has happen before but I had the trim up pretty high and was making a real tight turn. You guys are great and I appreciate all your expertise.

 

[QC]

Re: Boat trouble ruins the weekend

I think before you do anything else you need to eliminate the propeller concerns from the equation. No matter what, you need a spare, so you should just buy one. Then you get to verify if that is the issue AND you get the spare. That's where I would start. <br /><br />With that said, I still don't think that the prop is the issue as you can still get her on plane, just at a higher RPM. The high rev situations sound like ventilation to me. I know that it didn't seem to happen before, but it still sounds like ventilation as you say there was some turning involved . . .<br /><br />The last time that it ran well, what was the load i.e. people, beer, ice, anchors, chain, more beer, fuel, water, misc. stuff compared to now? I think I wrote that kinda backwards, but the point is that every single pound slows you down, so a comparison between previous good and now bad from a weight standpoint is important.

 

[Manipulator]

Re: Boat trouble ruins the weekend

I think before you do anything else you need to eliminate the propeller concerns from the equation. No matter what, you need a spare, so you should just buy one. Then you get to verify if that is the issue AND you get the spare. That's where I would start.<br /><br />Sounds like a good idea. I will have the mechanic check it out as I don’t have time to run down to the lake to do it myself (3 ½ hour trip). <br /><br />With that said, I still don't think that the prop is the issue as you can still get her on plane, just at a higher RPM. The high rev situations sound like ventilation to me. I know that it didn't seem to happen before, but it still sounds like ventilation as you say there was some turning involved . . .<br /><br />I can get on plane but I’m barely moving. Pushing the engine doesn’t seem to make it go any faster. <br /><br />The last time that it ran well, what was the load i.e. people, beer, ice, anchors, chain, more beer, fuel, water, misc. stuff compared to now? I think I wrote that kinda backwards, but the point is that every single pound slows you down, so a comparison between previous good and now bad from a weight standpoint is important.<br /><br />Last few times out it had four adults, two kids and a ton of gear plus two filled coolers. It ran fine and had plenty of get up and go. Even planed off fairly quickly with that much aboard. This time out it was just I with no one else on board and no coolers or added weight. Strange! What about the spun prop issue? To me that makes a lot of sense. The engine pushes but maybe there is so much slip its just not pushing the boat. Then again I ran it for 45 minutes or so and I would think if a hub or prop were slipping it surely would have broke. I did multiple planing off and I would have thought it would have given up under the stress.

 

[waterone1@aol.com]

Re: Boat trouble ruins the weekend

Have you looked at the bilge to make sure you haven't taken on water ?

 

[KaGee]

Re: Boat trouble ruins the weekend

Originally posted by Boomyal:<br /> At least some of the OMC stringers have flappers in the intermediate housing. Most likely the Hydro Mech and Mech units. I saw one at the shop with the flapper just hanging, partly attached, I suppose this could cause a proplem if it/they became detached.

Yes, my 800 has flappers. They are not the same as the Mercs or Volvo. If one becomes dislodged it most likely would fall out the minute you raised the drive. The biggest concern with a lost flapper would be with possible water up the riser in a wake or rough seas.<br /><br />I still think you need to have the prop checked out.

 

[Manipulator]

Re: Boat trouble ruins the weekend

Quietcat, mechanic checked it out and there is nothing wrong mechanically. He said the bottom has a 1/2 of growth. They power washed it and now it's fine. You were right!

 

[Manipulator]

Re: Boat trouble ruins the weekend

Oh yeah, cost to figure this out $334!