4K RPM max and will not go over 30.

[Scotttheimpaler]

My boat sat for 9-10 months, long story, but once I got it running again I took it out and it ran very poorly. I couldn't get passed 4K RPMs and or about 25 MPH. I change the inline fuel filter, put clean plugs in and got about 30 MPHs. I have now run most of the old gas out and was planning to add a half tank of clean, ethanol free fuel and some sea foam - but I suspect I'll get similar results. It smokes a lot - seems starved for fuel. The plugs were wet and black when removed.

Any suggestions?

I plan to try:
replace the fuel line (I replaced 2 sections that were bad already)
inspect the fuel pickup for cracks/blockage

Any suggestions?

 

[Dr Honda]

First..........


Seafoam is a solvent, and is a slow death to a 2-stroke. Don't use it.


Next.... the smoke could be caused by a few things... but generally when the top RPM's are low... you've lost spark on a couple plugs. So, check the spark on all 6, and let us know what you find.

 

[Sportster-2001-951C-Stock]

I agree concerning seafoam, the only fuel additive I consider safe is a fuel stabilizer to extend the life of the fuel.

And I agree you should change the plugs again, (Hint: I pull each one off the plug and then push it back on one at a time while engine is running to locate a dead cylinder, if no change while off this indicates that cylinder isn't firing).

 

[gioakjoe]

dang man all iv heard was to use seafoam but if dr Honda says no that makes me sad. I had to spend the day googling about seafoam

 

[UKGlenn]

Sounds similar to a problem I had last year. The alternator belt had snapped and the battery wasn't being charged. Might be worth trying a new battery.

 

[Sportster-2001-951C-Stock]

Sounds similar to a problem I had last year. The alternator belt had snapped and the battery wasn't being charged. Might be worth trying a new battery.

Good thinking, nice suggestion!

 

[Dr Honda]

his boat should have the early engine... so there isn't a belt. he has an internal mag.

 

[UKGlenn]

Ah ok. Could his battery still be weak not being able to provide enough currant to charge the coils at higher RPMs?

 

[Scotttheimpaler]

HI All,
thanks for the input.

Battery is like new and charged, all plugs are firing. I went to check my pick-up which was next on my list and noticed all of the fuel lines pulled out with relative ease while the crimp clamps were still in place. The date on the fuel line is Jan 93, which I found odd for a 2001 boat. I suspect I'm sucking air, my transparent in-line fuel filter was not filling with fuel. I removed the steal one years ago and added a barbed nipple and $4 off the shelf fuel filter years ago. My pick-up tube looked fine but the screen has a rip (better performance right? lol). Going to buy lines and replace them maybe Friday night. Then test it out sometime this weekend (hopefully).

 

[Scotttheimpaler]

I think it smokes so much because its getting the full amount of oil and 1/2 the amount gas it needs.

 

[Sportster-2001-951C-Stock]

Air in the fuel lines will definitely slow you down.

Also, put fuel pressure check on the list, you should find the Schraeder test port on the fuel rail leading to the injector banks. The high pressure fuel pump might not be up to the task or one of the in-line screen filters (if it has them) may be clogged.

Don't get too excited if the transparent fuel filter never fully fills, most I see only reach about half full with no ill-effect.

 

[Scotttheimpaler]

in line screens would suck! The pump is new and I still have the old one just in case. Hopefully I can post good news on Monday.

 

[Dr Honda]

As above... the clear filter will look empty, but fuel will flow. Basicaly, air can get trapped behind the paper.


Lets go down the list

1) If you have an air leak... that's BAD. A lean run on a 2-stoke will kill the engine. SO, double check ALL the hoses, and make sure they are clamped.

2) These engiens are sensitive to voltage. SO, a low battery can casue issues. BUT, if it can crank and start... it's probably OK. But, put a meter on the battery, and check it, a) Sitting, b) Cranking, c) at idle/running.

3) As above, check the fuel pressure. DO NOT GUESS.

4) You said you have spark on all 6, but then said you want to check the trigger. ?? Here again... DO NOT GUESS. verify, 100% that you have spark on all 6. Get 3 in-line testers (They are cheap) plug them in... start the engine, and simply look for a nice blue spark. It was suggested to pull the wires while running... but I don't recommend that. a) You can shock yourself. b) These engines idle just fine with a couple wires off. c) If you get a good spark, while removing it... you could cause an explosion from bilge fumes !!!!!!!!! You may get away with it on a 2/3 cyl ski, but not on a 6 cyl boat, and bilge explosions are real.

5) Check the compression. Post the numbers for us.

6) Did you verify that the throttle plates, at the engine are opening all the way?


A smoky 240 is absolutely normal at low RPM. Especially after it sits. Mine will fog out the dock when I first put it in the water, if it's been sitting for a week. Even after a long idle/low RPM ride... it will be wafting white smoke. It's simply how a 2-stroke is. With that said, a bad port side temp sender, or bad TPS will make it worse, but you will also have starting issues, and low RPM at idle. (Target idle is 1100 RPM in the water)

 

[Sportster-2001-951C-Stock]

First of all, if there are enough fuel fumes in your bilge to cause exploxion, I highly suggest you take care of that BEFORE doing anything else.

A spark checker won't tell you if one of the plugs is fouled.

 

[Sportster-2001-951C-Stock]

in line screens would suck! The pump is new and I still have the old one just in case. Hopefully I can post good news on Monday.

Which of the two electric fuel pumps is new, lift or high pressure?

Many of mercury's EFI systems have small in-line screens in various places, these are all downstream of the large spin-on can fuel filter which is a very effective device by itself.

Alas, I've seen low fuel pressure caused by debris clogging the inline screens and even injector screens many times. Also, debris gets into the high pressure fuel pump as well.

You cannot diagnose this problem without process of elimination, the boat won't perform if the fuel pressure UNDER LOAD is falling off.

While I'm thinking of it, if the fuel pressure regulator diaphragm is ruptured, there will be fuel flooding issues to some extent and hard to start due to fuel leaking into the intake system.

Fuel pressure regulator is item #6 in this diagram, the high pressure pump is #11. You need to confirm fuel pressure is adequate under full throttle load, when demand is high.

I usually use a dry rag that isn't fuel soaked from swabbing up fuel leaks or sometimes the plastic tool I keep handy for pulling plug wires with engine running is the yellow photo.

 

[Scotttheimpaler]

I replaced the lift pump.

Maybe I had my head upside down for too long while replacing the fuel lines, but I went ahead with the Seafoam. My justification was: 1. the engine sat for a 9-10 month and their is probably gumming/varnishing in the screens, jets, ports. 2. the oil is injected at the piston so I don't have to worry about it breaking down the oil. 3. I forget number 3 but it seemed logical at the time.

I replaced all the lines except 2 - the ones to and from the water separator. I will get to those this week then replace the separator. I added 15 gallons on ethanol free gas and my Seafoam, I ran the boat for about a 1/2 hour.

Ran 4500-4700 RPMs and topped out about 35. Was able to consistently get 30-35 as apposed to 25-30 last week. Still smokes heavily when I idle down - return to the dock.

Also, this stupid 4-1/2' water moccasin would not leave while I was trying trailer the boat.

 

[Dr Honda]

The snake is the least of your issues. Just give it to one of your kids. (lol) Most water snakes are placid, and won't bite, even when handled.


Anyway.... At this point... I would drain the fuel if you really think it's bad. Something you pour into the fuel, CAN NOT save bad fuel. SO... now you have bad fuel, and a solvent that can displace the oil that is lubing the engine. It's fine for a 4-stroke... but it's a slow death to a 2-stroke. The only thing that is acceptable in 2-stroke fuel (other than oil) is a fuel stabilizer, or enzyme for alcohol.


A word on fuel...

Fuel doesn't go bad as fast as some try to make out. I've burnt fuel that was over a year old with no ill effects. Heck... when I pull my boat out of hibernation in the spring... the fuel will be at least 8~9 months old... and I won't give it a second thought to fire up the boat, and throw it in the water.

Varnish: Well... that can only happen with evaporation and concentration. SO... it can't happen internal of a fuel injection system. BUT, it can happen in the Vapor tank. IF... you randomly start it during the winter.




With that out of the way.... if a 2-stroke isn't running the way it should.... STOP RUNNING IT !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! A small problem can lead to a melt down. So, a $10 problem can turn into $5,000 rebuild.


I'm sorry if I seem harsh. I just don't want things to get worse.



SO, go back to post #13, and lets check things.


1) Spark on all 6 plugs
2) Fuel pressure on the high side.
3) Compression.
4) Port side temp sender
5) TPS.


DO NOT GUESS. POST NUMBERS AS YOU GET THEM !!!!!!!!

 

[Dr Honda]

Let me clear up a few things.

I replaced the lift pump.

Maybe I had my head upside down for too long while replacing the fuel lines, but I went ahead with the Seafoam. My justification was: 1. the engine sat for a 9-10 month and their is probably gumming/varnishing in the screens, jets, ports. 2. the oil is injected at the piston so I don't have to worry about it breaking down the oil. 3. I forget number 3 but it seemed logical at the time.

From your number:

1) There are no "Jets" or "Ports" (in the common sense) in this engine. Jets are in carburators, and Ports are the intake tract in a 4-stroke. On this engine, the injectors are pointed directly behind the reed valves, and that goes directly into the crank.

2) No it isn't. The DFI engines get a direct oil injection. On your engine, it's mixed with the fuel in the vapor tank. So now that you have put a solvent in the fuel... it may not be mixing at all. (making smoke worse, and reducing it's effectiveness)

3) I'm sure it did. Lots of people justify poor decisions somehow.




Sorry for being blunt... but if you want help, you need to follow our advice.

 

[Scotttheimpaler]

I like to do the cheap/free stuff first - because I'm cheap.

1. checked them all, had spark on each wire, used a tester - did not pull each one while running (sorry). For now, I'm happy with the results but we can always come back to that.
2. How do I check that? is there a special tool? where do I check that? obviously after the high pressure pump but where specifically?
3. Boat ran fine when I garaged it in April 2015 - should still be good but it never hurts to check it, I should be able to get a loaner tool for that one and its fairly easy to do, will post results.
4. Part number 13536A14, $32.17 + free shipping on Ebay, on its way. Ordered an extra separator while I as at it.
5. I believe I saw a post on how to complete this task. Sounds cheap/free to check it. Ill get on that one this week.

Doubt that I'll do anything with it tonight. Might get the comp tool and check that.

 

[Dr Honda]

1) OK

2) as mentioned above.... there is a schrader valve on the regulator. You can use a simple tire pressure gauge if you want. (just wear gloves) The pressure isn't that high.

3) ok. But, when there are issues... you have to be methodical, and check everything. You could have built rust in a cyl, and cracked a ring when it started up. That will lead to low compression. OR... you could have a reed valve that gave up. (it will also show up as low compression)

4) good... but that sender won't keep it from making full power. Just hard starting, smoke, and burning too much fuel.

5) There's a bunch of threads on it. Just keep your fingers crossed that you don't find it's bad. (expensive)



I'm right with you on being cheap. I hate paying full price, and that's why I learned to fix my own stuff when I was very young. BUT, there's a point where being cheap, leads to spending more $$$.

 

[Scotttheimpaler]

2. Seems easy, will test tonight
3. tester is waiting for me at AutoZone
4. should be here Saturday - naively hoping this solves everything.
5. scared.

fix most of my own stuff but the boat baffles me at times (most of the time). I would prefer a 455ci. Olds with a carb, HEI distributor and an electric fuel pump.

 

[Scotttheimpaler]

2. Had 34-35 psi at idle.
3. Got the tool but by the time I got done with the fuel the stupid mosquitos where super thick. I moved back into the garage but the bilge has too much gas from the fuel test. I'll have to wait until tomorrow.

 

[Sportster-2001-951C-Stock]

35psi is spec I think. But if I recall that's ignition on engine not running pressure. Also note how long it holds pressure with ignition off.

Then the next thing I'd do is splash it and see if pressure drops off as the engine begins running out of steam.

If you're gonna DYI on 2-strokes (I encourage this) you need a compression gauge at some point, even if it's from Harbor Freight you can compare the reading to your sir compressor gauge to see if it's correct. The reason is if one cylinder is awol you can waste all kinds of time and money on parts and still won't run right.

 

[Scotttheimpaler]

I got a loaner gauge from autozone but ran out time last night, the mosquitos were out in full force last night, must finally be warm enough. March 1st and winter is over.

 

[Sportster-2001-951C-Stock]

Agree, seems winter is ending and spring is early.

Quick question, you mentioned the butterflies were stuck open at one point, I'm wondering what was going on with that might be related to the current issue?

And yes, there could be a problem with the reeds but those are kind of buried under the throttle bodies.... hmm...

If this motor has the trigger coil under the flywheel that moves as the throttle is moving (opening) this is how the ignition timing is advanced. That is, as throttle is applied the trigger under the flywheel moves to change (advance) the ignition timing (to about 22* max, I think). I'm pretty sure this one has the rotating trigger coil, this must move else no ignition advance occurs as throttle is applied.

As you move the throttle, is the trigger position changing (advancing the ignition) as well? The position of the trigger is important to ignition timing so avoid adjusting the linkage out of position else you'll have to readjust the timing using a timing light (dial-back type, probably).

Gotta go, scream at ya' later....