Rough Idle and Bogging on Holeshot

[BassCatKWG]

Hello All,

2010 BassCat Puma FTD DC
2010 Mercury Pro Xs 250 (ser# 1B764965) (app. 700 hours)

Awesome boat, have had it for a few years now, 80mph with a lot of chine walk, lol. Recently though, the engine has been missing a bit while idling in gear and bogging pretty bad when trying to get out the hole. It always eventually gets out but something is obviously not right. I am the second owner, the previous owner was a pro, and I have all the records for any service that was ever done to the boat (meticulous guy). I have a service manual and am somewhat familiar with engines. So with that said here is what I have done so far:

1. Changed plug wires
2. Changed plugs/gapped correctly (multiple times and plugs always look pretty uniform (brownish/tan tint) without any carbon buildup)
3. Changed fuel filter
4. Sprayed power tune in cylinders and let set over night.
5. Flushed motor and changed thermostats.
6. Water pressure is good on gauge, strong tell tale stream.
7. Temp is 130 (doesn't fluctuate much )
8. Fuel pressures (psi): running-107, 5 sec-100, 10 sec-97, 15 sec-93, 20 sec-89, 30 sec-82, 40 sec-80, 50 sec-76, 60 sec-72, gradually drops small amount after that.
9. Air pressure (psi): running-92, 5 sec-88, 10 sec-85, 15 sec-83, 20 sec-81, stayed at 81.
10. Compression: 1-112, 2-110, 3-110, 4-110, 5-110, 6-110
11. Pressure at VST: 27 psi
12. Changed compressor strainer.
13. Rebuilt pulse fuel pump.
14. New primer bulb and all fuel lines. (Primer bulb stays pretty tight)
15. New vented gas caps (from BassCat)
16. Pulled red fuel injectors. Checked O-rings and sprayed with power clean, re-installed.
17. Verified spark on all six wires with timing light.
18. Have one new coil and been moving it around in an attempt to catch an intermittent coil failure, no luck, plugs always look the same and runs the same.
19. New Exide 31 AGM with stud mount type connectors that Don recommends.
20. Resistance of injectors is 2.0-2.1- Specs are 1.9 but that is probably my digital meter off. All are the same.
21. TPS ohms good
22. Checked for fuel in air leaks by removing the air rail connection from both rails and running the fuel pump. No drips.
23. New belt and belt tensioner.

That's about all I can remember, lol. Been doing this over the past couple of months. Once it gets on plane it runs like it always did. I plan on sending the 12 injectors off and having them tested and cleaned. I am leaning towards the reeds. I haven't pulled the intake and plenum off yet, figured I would inspect and replace at the same time. I have a brand new set from Chris Carson and am going to install them when I get the time. With 700 hours on the stock ones I'm sure its time whether that is my problem or not. Looking down the butterfly there does seem to be a bit of DFI oil in the bottom of the plenum. Can't really say if I hear a "puffing or wheezing" as these optimax engines sound odd from the start. Always run Don's cocktail!

Any and all comments or ideas from you guys are greatly appreciated. This is my first time posting a thread on here but have been an avid reader/researcher for years.

Thanks!!!!

Forgot to add:

Smartcraft gauges (the ones with needle and digital readout [+ mode - buttons]), never has thrown any kind of alarm, always run non-ethanol fuel and DFI.

[Jtreed99]

Agree on reeds. The way I had it explained to me once before was that if there is a small chip it can leak enough at low rpm/low air flows to cause issues. As you move towards wot the total airflow becomes much higher (and the time between cycles much lower) and the slight slow leak at the reeds is much less noticeable.

[BassCatKWG]

Thanks Jtreed99, makes sense to me, reeds are for sure next step. I will update.

[Savage]

Oil in the plenum is perfectly normal. I would install TDR reeds.

[BassCatKWG]

Thanks for the reponse Savage. It's in the works, I have a brand new set of CCM reeds with stuffers, I own an HVAC company in Texas so needless to say I haven't found the time to get it done (105 degrees everyday, lol). I've read quite a bit about Boyeson, Doukas, and Carson reeds. It seems there is a wide variance of opinions. Your thoughts on pros and cons to different brands?

[BassCatKWG]

I did put a set of CCM reeds in an old Black Max years ago and it's ran great since. Chris, over the phone, has been great to deal with. Just wondering the differences.

[EuropeanAM]

While I agree that reed inspection and replacement is wise, I would STRONGLY urge you to stick with a CARBON fiber reed. They perform very well in your engine, and I personally prefer them to the Epoxy for THIS application/engine.

Available OEM or in TDR.

Also a good idea to check/monitor the MAP sensor function. Requires use of the Computer Diagnostic System, or a suitable scan tool that can access PCM data (of course, someone to accurately interpret that data is also good).

[BassCatKWG]

Thank you Don, I will consider carbon fiber, I already have the CCM epoxy ones though so may give those a go first. Any major concerns on going with glass in the proxs instead of carbon, or is it more a preference thing? I also ordered a new MAP sensor. That's one of the more "inexpensive parts" for these motors so I figured what the heck, I'll have a spare worse case scenario. What are your thoughts on getting an at-home monitor for these motors? Any affordable brand or specific company recommendations? I work on quite a few of these for friends and would love to be able to gather and interpret some data on a laptop myself. Thanks again, you must spend a great deal of time behind your computer to answer all these forums, we greatly appreciate it!

[EuropeanAM]

The fiber reeds will run well- perhaps even a bit smoother on the bottom-mid. I've heard a couple comments from folks on the top end (that have run both)... nothing drastic, just not quite the same. The epoxy are safer... so it's a matter of preference for the most part.

Diacom is perhaps the most cost-effective (moving forward not sure how far it will remain compatible, however).

[BassCatKWG]

Thanks again Don, you guys are great! These boards are a wonderful resource. I'll try my best to pass the help along sometimes on here. Will check out Diacom.

[RangerBasser]

Could easily be more than 1 coil failing. Happened to me...

[BassCatKWG]

Thanks RangerBasser, I have considered that possibility, when your coils failed were they intemittent? I have checked mine numerous times with a timing gun and have yet to see one not spark, always idling in a tank at home though, they may act completely different under a load. They all ohm at the correct specs. I just can't bring myself to spending the money to replace all 6 without a bit of verification, ya know.

[EuropeanAM]

While not impossible, the coils used on this particular serial number had a pretty low failure rate.

[tomloans]

Don I think I may have the same issue. Do you carry the TDR carbon fiber reeds and all other needed parts for me so that i can do it myself. Thank you.

Tom

[BassCatKWG]

I think Don may be preparing for a flood in Greenville, looks like that monster storm may be heading his way. Everyone out east try to stay safe! We had Harvey here last year. Colorado river went to second highest level in history. Truly terrible for many!

[EuropeanAM]

Don I think I may have the same issue. Do you carry the TDR carbon fiber reeds and all other needed parts for me so that i can do it myself. Thank you.

Tom

See Rhonda's Post (pinned at the top of the Forum)- if you drop her an email, she can set you up with what you need.

[tomloans]

See Rhonda's Post (pinned at the top of the Forum)- if you drop her an email, she can set you up with what you need.

Thank you.

[BassCatKWG]

Another question that I'm sure I probably know the answer to but here goes. While I have been working on this engine I have realized I have the common oil pump leak. I feel I am more than capable of replacing the o-ring with the proper size, but at almost 700 hours on this pump, I'm sure you guys would agree that I should probably just get a whole new pump assembly. Correct? Also, are the new OEM Mercury pumps improved from the original design that had o-ring leaks on some at 20 hours or so? Or is there any other pumps out there that are better? Thanks

[Savage]

Get a new pump.....no matter what, it IS the right thing to do on your motor.

[Gamblinman]

I've tried the Chris Carson and Tony Doukas reeds, I prefer Boyesen. Crisper idle and excellent performance. These were OEM in 250XB's.