My 2004 3d will not speed up past 1/4 throttle.

[Pedec]

I bought a 2004 3d and first day out it seemed to run really good. The next time a week later having hard time to get up on plane from lack of power like 1/4 power at full throttle. The front plug looks great but back plug is way more black looking. Compression 150 psi both cylinders. Fuel is fresh 91 octane premium fuel. Should I maybe run regular fuel 87 octane is what owner manual says? The same as day before other than adding 10L more 91 octane premium fuel. I changed both plugs with new plugs and same results just will not rev out pike 1/4 throttle. Stars extremely good and idles great. So any idea or help. Thanks.

 

[Pedec]

Exhaust seems fine with no leaks or exhaust gases in hull and flow water out side hull hose to tell it circulating. Reversed circulated exhaust cooling system no problem.

 

[Pedec]

Is there a limp mode or something? No engine lights. Battery is new and start instantly. Volts Seem normal while running.

 

[mikidymac]

You could try replacing the in-tank fuel filters as they are known to clog and cause issues.
Also check battery voltage at rest, at idle and at 4,500 rpm.

 

[Pedec]

Would it be worth putting any seafoam in fuel tank to see if that would help with filters and fuel injectors if they might be the problem. Like I said it weird the front cylinder plug look perfect and rear plug is a lot darker or richer looking.

 

[mikidymac]

No, don't use any additives.

 

[Pedec]

The battery is at 12.9v before starting once idling 14.0v and half or more throttle 14.10v is the most I seen. I do not have a tachometer to see what my idle speed was but the testing is done with ski out of water and just using backwash water hose to run ski on trailer so prop not in water. After running 3-4 mins and shutoff ski battery reads 13.10v.

 

[mikidymac]

Sounds like it isn't charging system related.

 

[Pedec]

It is not the exhaust cooling system it seems. Running motor with garden hose hooked up everything I touch is cool even the back under access panel a person stands on. Exhaust hoses and tee are cool to touch and no sign of heat or leaking. Thanks for help so far. Is that in tank fuel filter hard to change?

 

[mikidymac]

You have to pull the entire pump/sending unit but after that it isn't too hard. Not sure how hard to access it on a 3D though.

 

[mikidymac]

Here is some reading for you The RFI Spot.

 

[Pedec]

Ok read all 7 pages and thanks for the link. What I have learned. I should check the gap on the plugs I put in ski. Also take out my crank case sensor and see if there is any filing on it. Sound line filling can screw up the way it runs. If still not right probably pull fuel pump and change filters and pump maybe. On my 3d it would be really hard to change out injectors or take fuel rail off. Unless there is a secret way.

 

[Pedec]

Ok there was filing on crankcase sensor which I cleaned off and plugs were gapped .035 not .020 inches which they are now set correct. Started up seem to rev higher. Will need to test in water next. Will let you know how it turns out. Test with garden hose and only running 2-3 mins the plugs were still both wet after test run but motor did not get fully warmed up so it getting fuel. Hoping once fully warmed up will clean out and run like it did.

 

[Pedec]

So update 3d did not run great today again. Only 1/4 throttle then nothing more. Starts great plugs look ok not to dark or lean. I also clean back fire screen before I went out. Will 3d even start or get up to 1/4 throttle if fuel pump or filters are not working right or plugged and injectors are not getting enough fuel pressure? No light on dash. Thanks for any input battery/charge system and exhaust system seem fine. I am so surprised how it ran so good on first day and not good on last 2 days.

 

[Pedec]

One more thing I tested while out on the water. I took fuel cap off while running 3d it made difference at all motor ran like it did but still would not go past 1/4 throttle but still idle good and run ok up to that 1/4 throttle. Is that normal? I thought tank was under 5 psi pressure and excepted 3d to quit as soon as I took fuel cap off.

 

[etemplet]

Did you test the fuel pressure? As @mikidymac stated you should probably replace the fuel filters and look at the pump as well. You could have a bad battery, it happens. These skis are really sensitive to battery voltage. Your rectifier can seem good but still cause problems. Good Luck

 

[Pedec]

Battery not running 12.7v once running 14.1v at battery never lower it seems. Battery starts ski intestingly and never drops volts running.

 

[Pedec]

No I did not test fuel pressure which I will see if local dealer can do that for me.

 

[Pedec]

Once I put lanyard on can hear pump start then shut off so it must be getting up to pressure.

 

[Pedec]

Thanks for help.

 

[etemplet]

You can make a fuel test rig and it will be a whole lot cheaper than taking the ski to the dealer. You have lots of support here.

 

[Pedec]

I have decided to change fuel filter on fuel pump both of them. It looks like they have not been done in awhile and since I do not know how long ago they have been done might as well try that first i guess.

 

[Pedec]

Well fuel filters did not fix it. Seems the plugs are really wet and wide open throttle it just bogs. When first started it did seem to run better but after couples mins back to bog at wide open throttle. All testing after changing fuel filters is just on hose not in water. Just running for min one or 2 min at a time.

 

[Pedec]

So I changed plugs and tried again and it seems to run good when I first start it with no garden hose open. So I run to open garden hose and as soon as head start getting cold from garden hose running water it start to bog when giving it gas hard. Does that make sense. Can not run it long with out garden hose running out of water it get hot fast it seems. Any ideas or similar situation. Thanks for any help.

 

[mikidymac]

You really need to get it in the water. Running out of the water will tell you absolutely nothing other that it runs. Without a load on the engine there is no point in reving or running it.