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stx22
06-06-2011, 12:18 PM
Boat is a 1997 PS 205 w/ 5.7L EFI. While barefooting at the end of last season I noticed that the boat has "lost" a ton of top end. Maxed out at 39 mph's. I primarily slalom so the boat rarely gets over 36. Essentially, the boat maxes out (when running well) at about 40. When the throttle goes all the way down it starts to choke out a bit. If I bring the throttle back it will actually pick up a bit of speed/power.

I initially thought it may be a prop, but I now have my suspicions that it may be something else (prop looks fine). I then thought it might be a compromised/kinked fuel line above the in-line fuel filter so I replaced that. A little better, but not enough.

Plugs have been replaced, distributor cap looks fine (about 70 hours on it)... Since I primarily ski, I didn't put too much time into it last fall, but it is starting to affect even lower ranges and sometimes the boat will barely make it to 36.

Any suggestions would be appreciated, season is too short...

BG1772
06-06-2011, 12:47 PM
I had a similar sounding problem on mine last year 205v (in the form of a 2001 X-Star). I lost top end peformance (both power and speed). Ended up being the exhaust silencer was blocking the output of exhaust and water at high RPM. At lower RPM everything was great, but at higher RPM the additional pressure would push the "shelf" in the silencer against the 2 output ports. This esentually "choked" out the motor. "Fixed" the silencer and boat is running better than ever.

stx22
06-06-2011, 01:46 PM
BG1772, Thanks for the tip. Any chance you can let me know how you "fixed" the problem? Does it require getting at the exhaust under the tank or around there? Also wondering if this can be done in the water or if it requires yanking the boat.
Thanks again, will the next thing I check off the list.

BG1772
06-06-2011, 01:54 PM
Is yours a V-Drive or an Inboard? I am assuming that yours is a inboard since you did not say it was a 205v. Mine is an V-drive, so this may not apply to you.

Do you have the large exhaust silencer that both manifolds plug into? It is perpandicular to the exhaust. Both manifolds go into it and then two pipes come out the bottom and go to through the transom. To "fix" mine, I pulled the silencer out (probably cold do this in the water, but I wouldn't). Once it was out, I looked in the out ports and could see that the shelf, which creates the baffle, was blocking off the ports. I took a 3.25" hole saw and cut a hole through the shelf where it was blocking the flow of water and exhaust. I figured what do I have to lose as it would probably have to replace the silencer if this did not work. The boat is a little louder than it was, but it doesn't bother me.

stx22
06-06-2011, 02:31 PM
I see what you are talking about now. I seem to recall seeing silencers on at the end of the exhaust hose prior to the through fitting.

Do you have any idea what was blocking the flow? Was there anything in particular that was clogging the silencer? I am wondering if just removing them and cleaning them out will work.

supturb89
06-06-2011, 02:38 PM
stx22,

I have a 96 with the same motor as you and it is having some of the same symptoms you describe. At WOT the motor seems to bog down a bit and by backing the throttle off slightly it will smooth out. Top speed right now is 39 mph (gps indicated). I don't have mufflers on mine so I don't believe this is the problem?

stx22
06-06-2011, 02:43 PM
Supturb89,
To be honest, I am not sure that I have the silencer, but something leads me to believe that I do. I only say this because I recall seeing something on the exhaust pipes that said "silence" when I replaced the sending unit the summer before last.
Let me know if you find anything that works on your end. I will hit you with a PM and we can compare notes.

JimN
06-06-2011, 03:18 PM
If top end is a problem and it smooths out by backing off of the throttle, it could be a fuel volume issue, which can show up on a pressure gauge. Clean the screen at the inlet side of the fuel pump and it should go away.

If that doesn't help, check the fuel line from the tank to the pump- if it's being squeezed under the tank, you'll never get the proper flow. Also, the company that made the hose had a problem about that time with internal de-lamination, which may or may not be visible from either end.

supturb89
06-07-2011, 08:54 AM
If top end is a problem and it smooths out by backing off of the throttle, it could be a fuel volume issue, which can show up on a pressure gauge. Clean the screen at the inlet side of the fuel pump and it should go away.

If that doesn't help, check the fuel line from the tank to the pump- if it's being squeezed under the tank, you'll never get the proper flow. Also, the company that made the hose had a problem about that time with internal de-lamination, which may or may not be visible from either end.

Thanks Jim....will check all those things and report back.

stx22
06-08-2011, 11:35 AM
Supturb89, any luck with the fuel pump filter? Anyone have any tips for getting at the fuel filter on this boat?

supturb89
06-08-2011, 11:45 AM
I was in the process of removing it last night, but my 2 year old son had other plans for me so I wasn't able to get to it. I removed the hose that goes from the raw water intake to the trans cooler to have better access. From there you should just have to remove the wiring connector and unscrew each end from the fuel line. The pump itself looks to be held on with two small allen head bolts. From reading through other threads on this issue I plan on finding a bunch of junk in the screen of mine and hopefully cleaning it will cure my problem.

stx22
06-08-2011, 10:21 PM
By way of update, I went through the entire fuel system (filters, pump, tank, lines, etc..) everything checked out and I still had the same problem with top end power and speed.
I finally tried cranking the bolt below the distributor cap a fraction counter clockwise (don;t ask) so that the two red lines are very slightly offset.
Took the boat out and it seemed to run great. No problem with the top end and almost back to normal. Topped out at 42.7 on the GPS which is pretty close to where it should be. I may make another minor adjustment tomorrow to see what happens. Anyone know why this may have "fixed" things and do I need to worry about any damage from taking this action?

thatsmrmastercraft
06-09-2011, 09:42 AM
By way of update, I went through the entire fuel system (filters, pump, tank, lines, etc..) everything checked out and I still had the same problem with top end power and speed.
I finally tried cranking the bolt below the distributor cap a fraction counter clockwise (don;t ask) so that the two red lines are very slightly offset.
Took the boat out and it seemed to run great. No problem with the top end and almost back to normal. Topped out at 42.7 on the GPS which is pretty close to where it should be. I may make another minor adjustment tomorrow to see what happens. Anyone know why this may have "fixed" things and do I need to worry about any damage from taking this action?

You tried cranking the bolt below the distributor cap counter clockwise? As in loosening the distributor and adjusting the timing without using a timing light?

stx22
06-09-2011, 10:04 AM
Yep, pretty much. It was suggested to try it since I had tried everything else. I was pretty desperate so I figured I would give it a shot. Problem fixed... Which leads me to my next question, what did I screw up while "fixing" the problem. I obviously know nothing about timing (yet).

thatsmrmastercraft
06-09-2011, 11:30 AM
For future reference, anytime there is a performance problem, it is imperative that all the basics get verified prior to searching for the problem. This means, in addition to replacing the plugs and inspecting the distributor and rotor, you would need to check timing and idle speed, plug wires and connections, replace fuel filters & clean all battery terminals. Often times the problem is with one of the basic parts or functions and saves a lot of time.

stx22
06-09-2011, 12:00 PM
I guess what I meant above was "fixed" as a question. I checked all the basics mentioned, but didn't think to check the timing. For some reason I was convinced it was a fuel or injection problem since initially I noticed a potentially compromised fuel line from the in-line filter to the TBI. Did some math and obviously added it all up wrong.

My general question is this, before I start running the boat what harm can I do now if the timing is still slightly off. And, what damage could I have done by running the boat as it was for a period of time.

thatsmrmastercraft
06-09-2011, 12:04 PM
I guess what I meant above was "fixed" as a question. I checked all the basics mentioned, but didn't think to check the timing. For some reason I was convinced it was a fuel or injection problem since initially I noticed a potentially compromised fuel line from the in-line filter to the TBI. Did some math and obviously added it all up wrong.

My general question is this, before I start running the boat what harm can I do now if the timing is still slightly off. And, what damage could I have done by running the boat as it was for a period of time.

No harm if it only a little off. If it is starting hard or pinging, you are too far advanced and could cause some problems. Either way, setting the timing is a quick job and worth doing.

JimN
06-09-2011, 12:10 PM
By way of update, I went through the entire fuel system (filters, pump, tank, lines, etc..) everything checked out and I still had the same problem with top end power and speed.
I finally tried cranking the bolt below the distributor cap a fraction counter clockwise (don;t ask) so that the two red lines are very slightly offset.
Took the boat out and it seemed to run great. No problem with the top end and almost back to normal. Topped out at 42.7 on the GPS which is pretty close to where it should be. I may make another minor adjustment tomorrow to see what happens. Anyone know why this may have "fixed" things and do I need to worry about any damage from taking this action?

If the base timing is advanced too much, the total timing advance will be excessive and under the right conditions (extremely hot & dry air, running at WOT with low octane gas), you can have detonation (usually called pinging or spark knock). This also can damage the valves and valve seats over time.

Did you take a fuel sample?

stx22
06-09-2011, 12:46 PM
JimN - I did not take a fuel sample. It was running without top end at the very end of last year and only noticed it when I was barefooting and telling the driver to hammer it. Other than an occasional foot the boat rarely gets over 36.
I filled the tank at the start of this season (about 2 weeks ago) with premium gasoline. I have always run premium gas in the boat and I put the same fuel in my car (with no adverse effects).

As for those conditions, we do not get them around here (hot and dry), but I wish we did. I will do a more thorough analysis tonight. I am hoping to get an additional 1000-1500 hours on this boat before I retire it/me.

supturb89
06-10-2011, 11:26 AM
Just to update I got to the inlet screen on my fuel pump and it had a little debris on it, but not like what others have found. I also changed both fuel filters. Took the boat out last night....what a difference!!! Boat seemed to jump out of the hole and WOT had no hesitation. I was able to hit 40mph with the bimini up, which hadn't happened in the past.

thatsmrmastercraft
06-10-2011, 11:38 AM
Have you verified where the timing is at yet?

stx22
06-10-2011, 11:58 AM
Have not verified yet. Got home last night and we were having a huge T-storm with serious winds, the works... Didn't think it was safe to be on the water.
I should be able to get to it tonight before the Bruins game and verify. Can you verify whether or not I need to put this engine in service mode?

thatsmrmastercraft
06-10-2011, 12:04 PM
I imagine so, but not sure. My boat is 20 years older than yours.

stx22
06-10-2011, 12:14 PM
I wish my boat was going to be as cool as your is in another 20 years. Great boat, but the styling in the late 90's is not... (in my opinion) ever going to "classic." To be honest, I never thought I would keep a boat this long.

stx22
07-08-2011, 11:35 AM
I hate to beat a dead horse, but I am out of ideas... Again.

By way of update: I got everything smoothed out. Replaced the cap and rotor and got the timing dialed in. The boat runs great, but still won't exceed 40.8 MPH on the GPS. I am convinced that I should be able to run close to 44, despite being an older boat.

After I got the boat running well (without top end) I broke down and brought it to the pros. I paid a bunch of money for them to test drive it and tell me nothing is wrong.

The claim no codes came up end everything checks out. They couldn't offer me any suggestions on what could be at issue.

The other issue I seem to be having is the boat does not hold speed very well when towing skiers, particularly after being run for a while. Perfect pass (stargazer 3-event) is essentially worthless and hand driving requires constant increase in throttle.

I'm going to throw it out there again and beg for suggestions.

JimN
07-08-2011, 12:24 PM
I hate to beat a dead horse, but I am out of ideas... Again.

By way of update: I got everything smoothed out. Replaced the cap and rotor and got the timing dialed in. The boat runs great, but still won't exceed 40.8 MPH on the GPS. I am convinced that I should be able to run close to 44, despite being an older boat.

After I got the boat running well (without top end) I broke down and brought it to the pros. I paid a bunch of money for them to test drive it and tell me nothing is wrong.

The claim no codes came up end everything checks out. They couldn't offer me any suggestions on what could be at issue.

The other issue I seem to be having is the boat does not hold speed very well when towing skiers, particularly after being run for a while. Perfect pass (stargazer 3-event) is essentially worthless and hand driving requires constant increase in throttle.

I'm going to throw it out there again and beg for suggestions.

Has your prop been repaired?

stx22
07-08-2011, 01:35 PM
Yes, my prop was repaired quite some time ago (about 10 years ago). That was my initial suspicion as well. The tech who just "worked" on it ruled out the prop as a potential culprit. He didn't offer a reason why, just said he didn't think that could be it.

I supposed it can't hurt anything but the wallet to try that as a fix. No rattling, vibration, pulling, etc

JimN
07-08-2011, 03:09 PM
Yes, my prop was repaired quite some time ago (about 10 years ago). That was my initial suspicion as well. The tech who just "worked" on it ruled out the prop as a potential culprit. He didn't offer a reason why, just said he didn't think that could be it.

I supposed it can't hurt anything but the wallet to try that as a fix. No rattling, vibration, pulling, etc

What RPM at WOT and speed?

autgbm
07-09-2011, 07:29 AM
I'm having this same problem (very bad high end performance - 35 mph max, limited power, bad vibration in neutral, and uses 30% more fuel to run with very bad exhaust smell in the water) with my 2001 X-30 and I've heard that the new fuel with ethynol is the issue and that MC as an upgrade that you can purchase to fix this issue. Any truth to this. I've heard that ethynol makes the rubber gas hoses break down and sensors on the engine are some how fooled by ethynol and requires more gas to operate. Not sure where the vibratrion in neutral comes into play.

JimN
07-09-2011, 08:26 AM
I'm having this same problem (very bad high end performance - 35 mph max, limited power, bad vibration in neutral, and uses 30% more fuel to run with very bad exhaust smell in the water) with my 2001 X-30 and I've heard that the new fuel with ethynol is the issue and that MC as an upgrade that you can purchase to fix this issue. Any truth to this. I've heard that ethynol makes the rubber gas hoses break down and sensors on the engine are some how fooled by ethynol and requires more gas to operate. Not sure where the vibratrion in neutral comes into play.

You have at least one fouled plug, bad plug wire or possibly a bad gasket if it vibrated in neutral. Ethanol won't cause a vibration and you don't have rubber fuel lines.

If you use a lot more fuel than normal and it doesn't have a bad vibration, check the ECT sensor (engine coolant temperature) that reports to the ECM, or its plug/harness. Also, check the MAP sensor and scan it for codes. If the MAP sensor has a problem,

stx22
07-18-2011, 11:36 AM
JimN,

4100-4160 and 41.6-42.0 MPH (better than two weeks ago). Mechanic claims no codes. Still out of ideas...

Still losing more power than usual when pulling skiers through the course. Anychance this could be related to PP? I am running Stargazer 3 event.

JimN
07-18-2011, 12:28 PM
JimN,

4100-4160 and 41.6-42.0 MPH (better than two weeks ago). Mechanic claims no codes. Still out of ideas...

Still losing more power than usual when pulling skiers through the course. Anychance this could be related to PP? I am running Stargazer 3 event.

I would try it with PP completely disconnected from the throttle. If you can maintain speed manually, it could be PP needs adjusting.

The speed vs RPM looks pretty close, though. That engine should top out at about 5K RPM but if the load is large and the prop is more aggressive than normal, it will drop the RPM.

autgbm
09-03-2011, 10:55 AM
My MC dealer finally found the issue, a bad coil. Runs like new now but not sure why this wasn't found originally but glad to move on. Love all the power!

thatsmrmastercraft
09-03-2011, 12:11 PM
My MC dealer finally found the issue, a bad coil. Runs like new now but not sure why this wasn't found originally but glad to move on. Love all the power!

For future reference, anytime there is a performance problem, it is imperative that all the basics get verified prior to searching for the problem. This means, in addition to replacing the plugs and inspecting the distributor and rotor, you would need to check timing and idle speed, plug wires and connections, replace fuel filters & clean all battery terminals. Often times the problem is with one of the basic parts or functions and saves a lot of time.

The coil wouldn't be at the top of the list of basics, but should have been caught earlier. Problems that present themselves as though they could be ignition or fuel issues double the possible cause and sometimes it is hard to stay focused on following the proper diagnostic order.

Glad to hear you are back in the pink.