Mercriuser 3.0 only reaching top speed of 25 mph and 3500 rpm, and steering is tight

I have a 1998 Sea Ray bowrider 180. It has a Mercruiser 3.0 I/O on it. I am having 3 issues with the boat that I want to fix. First of all my top speed I am reaching is only about 25 mph and that is at about 3,500 rpm's. The second issue I am having is that the steering is extremely tight when at low speeds but the boat has power steering. The third issue is my GPS shuts off by itself a lot and so does my CD player if I try to turn it up loud. I am wondering if this is an equipment issue or power issue. Please help.

Re: Mercriuser 3.0 only reaching top speed of 25 mph and 3500 rpm, and steering is ti

We can probably help you on the engine and steering, but your GPS problem needs to be posted over in the Electrical, Electronics, Audio and Trolling Motors forum.

As far as the steering goes, what usually happens is corrosion builds up between the aluminum tube through the PS cylinder and the SS cable end. Remove the cable, clean the tube out, grease it up and your steering will work like new.

Speed could be a number of things, is this boat new to you? Do you use the trim?

Re: Mercriuser 3.0 only reaching top speed of 25 mph and 3500 rpm, and steering is ti

The boat is new to me. Actually this is my first boat. I have been shown how to drive it and do use the trim. I find I get the best performance when I have the trim up 1/4 of the way. The boat does have a hydrofoil on it.

I have looked at the engine and it looks pretty clean. I have purchased new spark plugs but have yet to install them. The prob is only a 17 and I want to put a larger pitch on there but I know doing that will prob only slow the RPMs down.

Where do I take the steering cable off? Back at the motor or behind the wheel? I have heard that is a known issue.

Thank you so much for your help! I am excited to being a new boater and i want to educate myself and learn the proper ways to maintain my boat.

Re: Mercriuser 3.0 only reaching top speed of 25 mph and 3500 rpm, and steering is ti

Forget about changing props for now. If you have a 17, it should work fine or be under propped (to high WOT rpm) not to low.
Here is a thread that lists the items that can cause low WOT rpm,
http://forums.iboats.com/showthread.php?t=295070

Here are links to download the OEM service manuals for your drive. Need to know your engine Merc serial number to get the right one.
You will find a metal tag just aft and above the starter.
http://www.4shared.com/document/dPQUcyn_/Service_Manual_14.html

Re: Mercriuser 3.0 only reaching top speed of 25 mph and 3500 rpm, and steering is ti

Don, you are the MAN! Thank you so much for all the great info! I am actually really excited to trouble shoot and find/fix the source of my issues!

After searching online I have seen a lot of people say they had the same steering problem as I do. Do you have a thread here that maybe shows a step by step process of how to remove, clean, lube, and reinstall the steering cable the correct way? I know this is prob a really simple process but for us new boat owners that want to learn I think this would be a great first fix for us to do to get our confidence level up before attacking more serious issues.

Another suggestion if you don't already have this is you should make a YouTube channel with HOW TO videos. Those help out a ton and you could make some good side money just by having google adsense on them. It won't cost you are your viewers anything either. Just a suggestion.

I am very grateful there is a site like this and people like you willing to help us newbies to the boat world. Thank you again!

Re: Mercriuser 3.0 only reaching top speed of 25 mph and 3500 rpm, and steering is ti

I don't think it requires a video to lube the steering cable. This picture should do the job.










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Re: Mercriuser 3.0 only reaching top speed of 25 mph and 3500 rpm, and steering is ti

I know this might sound like a stupid question but once I disconnect the cable from both ends, do you recommend I just clean the cable itself from beginning to end and then lube it up as I feed it back into the tubing, or am I cleaning the actuator that it connects to back at the motor, or both? I just want to make sure I do it right the first time. I was an aircraft electrician in the Air Force so i am a stickler about following directions and using the right products, tools, etc.

Also, what cleaning method do you suggest and what products?

Re: Mercriuser 3.0 only reaching top speed of 25 mph and 3500 rpm, and steering is ti

You will need to clean the SS rod end of the steering cable, plus the tube that goes through the power steering unit. Then lube it up with some good quality grease and put it back together.

Re: Mercriuser 3.0 only reaching top speed of 25 mph and 3500 rpm, and steering is ti

If you have guns, a shotgun barrel brush works well to clean up the aluminum steering tube. Or you could use a small brass brush with a plastic handle and melt the handle straight, so it will fit into the tube, then clean it from both sides.

If your engine is only turning 3500RPM WOT with the 18' boat turning a 17P prop and running 25MPH, something isn't right. Checkout the stickies at the top of this forum and look for the troubleshooting guide for WOT RPM problems.

Re: Mercriuser 3.0 only reaching top speed of 25 mph and 3500 rpm, and steering is ti

Ok, I am going to take care of the steering issue today and just to make sure I do it right. When I disconnect the cable from the power steering at the motor, i will clean the cable there. My only question (and sorry if this sounds dumb) but will I need to or can I even pull the entire cable out of the ruber tubing and clean from beginning to end? Or am I just cleaning the cable where it connects to the power steering?

Sorry guys, I know these sound dumb to yall but I just want to get it right before I start working on the boat in this hot georgia weather...haha

Thanks again for all the help!

Re: Mercriuser 3.0 only reaching top speed of 25 mph and 3500 rpm, and steering is ti

can I even pull the entire cable out of the ruber tubing and clean from beginning to end? Or am I just cleaning the cable where it connects to the power steering?

Click to expand...

You can't take the cable apart, if the cable was binding, you would just have to replace the cable/helm assembly. You are just cleaning the cable end and aluminum tube. It's very common for the SS cable end to corrode in the aluminum tube.
When you remove the cable retaining nut, you will probably be able to very easily turn the wheel as only the cable will move.

Re: Mercriuser 3.0 only reaching top speed of 25 mph and 3500 rpm, and steering is ti

I took the boat out yesterday to do a little bit of field troubleshooting (and have a lil fun) and I have question about my max RPM of between 3500-4000 and reaching a top speed of only 25 MPH. I have a feeling it might be a fuel supply issue. The reason I feel this way is because when I am at idle and got to WOT, it feels and sounds like the engine is asking for more fuel than it is recieving. I saw this because to get the best performance, I have to put the throttle all the way down and then pull back on the throttle to allow the engine to catch up. Also it takes a very long time for the boat to get on plane and pulling a skier up is almost impossible. Once it does reach plane, it rides smooth but only turning about 3,700 RPM and goes only 25 MPH.

I asked the previous owner if they changed out anything and he said the fuel/water separator was changed out. When I looked at the engine, there is a metal fuel tube coming out of the carb but they connected this metal fuel tube to a rubber fuel tube that looks a lot thicker. At the end of this rubber tube it connects back to a metal fuel tube. I think they may have done this to relocate the new fuel/water separator. Do you think this has anything to do with my problem?

Here are some pictures of my engine. Please help and thank you

Re: Mercriuser 3.0 only reaching top speed of 25 mph and 3500 rpm, and steering is ti

I took out the pin and removed the retaining nut but I can not pull the whole cable out of the tube. Am I just supposed to clean the cable itself and the end of where the cable connects?

Does this sound like a fuel problem to you? My boat won't reach top speed.PLEASE HELP

Does this sound like a fuel problem to you? My boat won't reach top speed.PLEASE HELP

I took the boat out yesterday to do a little bit of field troubleshooting (and have a lil fun) and I have question about my max RPM of between 3500-4000 and reaching a top speed of only 25 MPH. I have a feeling it might be a fuel supply issue. The reason I feel this way is because when I am at idle and got to WOT, it feels and sounds like the engine is asking for more fuel than it is recieving. I saw this because to get the best performance, I have to put the throttle all the way down and then pull back on the throttle to allow the engine to catch up. Also it takes a very long time for the boat to get on plane and pulling a skier up is almost impossible. Once it does reach plane, it rides smooth but only turning about 3,700 RPM and goes only 25 MPH.

I asked the previous owner if they changed out anything and he said the fuel/water separator was changed out. When I looked at the engine, there is a metal fuel tube coming out of the carb but they connected this metal fuel tube to a rubber fuel tube that looks a lot thicker. At the end of this rubber tube it connects back to a metal fuel tube. I think they may have done this to relocate the new fuel/water separator. Do you think this has anything to do with my problem?

Re: Does this sound like a fuel problem to you? My boat won't reach top speed.PLEASE

Re: Does this sound like a fuel problem to you? My boat won't reach top speed.PLEASE

Why don't you just replace the rubber hose with something else and see if it will reach 4400-4800rpm then, but I'm doubting it?
Does the engine run smoothly otherwise? Do you have the correct propeller? Is the gear ratio correct?

Re: Does this sound like a fuel problem to you? My boat won't reach top speed.PLEASE

Re: Does this sound like a fuel problem to you? My boat won't reach top speed.PLEASE

The engine runs very smooth. The prop is undersized if anything. It is only a 17 pitch. I would think that would be too high of RPMs. I am not sure about the gear ratio. This is my first boat so i am learning as I go. Any advice would be great

Re: Does this sound like a fuel problem to you? My boat won't reach top speed.PLEASE

Re: Does this sound like a fuel problem to you? My boat won't reach top speed.PLEASE

for sure get rid of the rubber hose going between the fuel pump and carb. it is not uscg approved and it is a fire/explosion hazard. run solid metal line between the two. i don't think it's the cause of your not reaching wot either though.

look at #13 from here. your s/m may be available if ya look in the mercruiser info (#10) section of that too. it may have some further ideas (in the trouble shooting section if it has one) on not being able to reach wot.

Re: Does this sound like a fuel problem to you? My boat won't reach top speed.PLEASE

Re: Does this sound like a fuel problem to you? My boat won't reach top speed.PLEASE

Dumb question..... How old is the fuel? Did you use Sta-bil or another fuel protector when storing it? "Corn gas" [ethanol ] is a problem for boats. Jerry

Re: Does this sound like a fuel problem to you? My boat won't reach top speed.PLEASE

Re: Does this sound like a fuel problem to you? My boat won't reach top speed.PLEASE

Fuel is brand new.

Engine Won't Reach Operating RPM. Check list help please

Engine Won't Reach Operating RPM. Check list help please

I am trying to work through this closed threads advice but I don't know how to do some of these things. Can anyone help? This is my first boat and I am learning as i go.....

Engine Won't Reach Operating RPM. Check

1. Fuel condition. Type and Octane possibly old fuel.....New fuel, even put in sea foam cleaner and octane booster to try to help clean out the system.

2. Propeller pitch or diameter, damaged blades ....Prop is Stainless Steel but only a 17 pitch

3. Restricted fuel pickup tube or anti siphon valve Fuel System Test....I need to do this

4. Crankcase oil volume, high oil level can cause aerated oil and lifter collapse....Oil is at perfect level

5. Marine growth on hull and outdrive ..... I cleaned the entire boat

6. Wrong gear ratio in outdrive......How do I check this?

7. Restricted carburetor air intake (clogged flame arrestor).....How do I check this?

8. Restricted exhaust system (broken exhaust shutters/flappers) in engine transom shield or drive.....How do I check this?

9. Poor cylinder compression Compression Test.... I need to do this

10. Carburetor defective, or wrong type.....How do I check this?

11. Fuel pump pressure and vacuum.....I need to check this.

12. Boat overloaded, improperly loaded, or improperly trimmed...... not an issue

13. Engine Overheating..... Not an issue

14. Engine timing and ignition system operation.....How do I check this?

15. Remote control cables and linkage for proper travel to open throttle plates fully....How do i check this?