Chipped/broken reed valves

[ChrisCarsonMarine]

We have found a very high incidence of chipped and broken reeds in Mercury motors equipped with rubber coated reed cages,which came in to use in 1996,and are still in use.These reeds are used in almost all carb,EFI,and optimax motors.Our replacement composite reeds will not only outperform the original steel reeds,but will protect your motor from major mechanical damage should a steel reed break.Consider the reed change an inexpensive powerhead insurance,with a performance gain to boot!Call if we can help,800-329-2725,Chris...see our Yellow CCMS banner add on BBC.

[cactusworms]

Chris,

I have a 2006 250XS, it has a miss wile idling, but top end is fine. It seems like it could be a reed thing. Do you think this rough ideal could be a broken reed, and if so what do you suggest?

THANKS

[EuropeanAM]

Larry:

Reeds are certainly a possibility. Your 250XS is equipped with a Carbon Fiber Reed (from the factory)... and they're not that difficult to inspect.

There are other possibilities as well.... a good starting point would be to have your serial number (and hours if available).

[MET]

Chris, not to hijack your post, but I have exactly the same engine, same year and same problem. I just had a complete service done, filters, lower unit, plugs, etc. It was doing it before and still doing it now.

My fuel lines and bulb have all been replaced with ethanol approved product, from Don.

My miss/skip is at idle, but ONLY idle in gear. Idle out of gear is normal.

My motor has 290 HRS and serial number is 20061E001594

Other than this, no real issues since new....knock wood!

I do use Quickleen and Stabil every gallon I burn.

Maybe Don can help us trouble shoot this together.

Thanks,

MET

[cactusworms]

Met,

You absolutely have described what my motor is doing to the T. Hopefully we’ll get some help with both

[ddantidwell]

I would be willing to bet alot of money that it is a broken reed for both. I just had the same problem and i changed mine myself. Its really easy to do if you have a manual. I wish i would have taken pictures of mine. The cause was it sucked up a small twig and it was lodged in my reed cage. If you have any trash in the bottom cowling be sure to remove it cause it will find its way into your motor.

[EuropeanAM]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by ddantidwell &raquo;</td></tr><tr><td class="quote">I would be willing to bet alot of money that it is a broken reed for both. I just had the same problem and i changed mine myself. Its really easy to do if you have a manual. I wish i would have taken pictures of mine. The cause was it sucked up a small twig and it was lodged in my reed cage. If you have any trash in the bottom cowling be sure to remove it cause it will find its way into your motor.</td></tr></table>

+1 on Dan's comments above!

Additionally.... for those of you having a spiratic misfire/skip AT IDLE, IN GEAR between 550-1100 RPM: INSPECT YOUR SPARK PLUGS. I don't care if you installed them yesterday: INSPECT THEM UNDER MAGNIFYING GLASS WITH BRIGHT LIGHTING.

Look for ANY signs of a lengthwise line in the porcelain surrounding the electrode. If you see ANY lengthwise line- REPLACE THE PLUG- IT'S LIKELY CRACKED. Been there... done that... and you'll chase your tail FOREVER over something you "think" has already been addressed.

If you look carefully at the below picture (heavily magnified)... you can "just" see a crack in the porcelain. This plug had approximately 5 hours on it- and was causing a similar symptom (it had been replaced to ADDRESS the symptom- and was also cracked, causing misfiring):



Additionally: You may find that increasing your spark plug gap (specifically on the 2006 model) to .038-.044", OR using 1 grade higher octane fuel (89 octane) may improve idle quality.

Another common culprit: Fouled/Dirty Direct Injectors.

[cactusworms]

Don,

THANKS, when I get home I'm going to check my plugs. I will probably replace them anyway to eliminate them from the equation.

[MET]

Thanks Don!! As usual, great info!! Will check for sure!

[Tom Rollins]

Nephews 2006 Opti 200 suddenly lost power and would not rev over 5000, no miss but motor had a different sound. Computor diagnostics showed all was well.
Had a one chipped and one bent reed. Tech replaced with Boysen's and motor runs better than new. Better holeshot, midrange punch and overall throttle response.

[ChrisCarsonMarine]

Just imagine how well it would run if you had used ours

[Tom Rollins]

Asked him about yours and TDR reeds, his reply was that he's never had a bad Boysen so why change.

[ChrisCarsonMarine]

Tom,I had a wonderful hamburger tonight for dinner,ground sirloin-medium rare,lettuce,tomato,mayo and catsup,sweet pickle on the side...prepared with love and care by my dear wife.Although she hasn't made the millions of burgers the most well known burger company in the world has, given the chance after careful comparison,I think you might agree that a name isn't everything,and mass produced goods aren't necessarily the best.

[MET]

cactusworm,

For what it's worth, I have my motor being serviced as I type, by someone that I (and most people around Lake Lanier) consider to be one of the best Merc wrenches around. I described the symptom, and he immediately said: "seriously doubt plugs or reeds. It has to do with the rpm's on the 250XS at idle in gear. Said I was feeling the prop ratcheting at the lower rpm's at a certain point in the rotation. Feels like a miss or skip, but not.

He said he would cheat a bit higher idle on the Throttle position sensor and would fix the problem.

I am not positive I have explained this correctly, but I will post when I get it back and let you know. If this doesn't fix the problem, plugs and reeds are next to check.

I am not trying to offend anyone's expert opinion here, just stating what I have been told.

Thanks,

MET

[PlanoKeith]

What Prop are you running MET?

[MET]

I have 3. It does it with all 3 of them.

Right now I am running a Merc lab finished Bravo 26. Cup and PVS plugs added by Mark Croxton. Best OVERALL fishing prop I own.

I also have a 25 Tempest Blueprinted and worked by Mark. Faster than the Bravo, but not near the hole shot, midrange or handling of the Bravo.

The fastest prop is a Rich Boger 27 Tempest he built specifically for the Z21-250XS combo. Wish I could find another one. Rich is retired now.

Mark does great work however.

MET

[PlanoKeith]

Okay I have a Turbo TXP ot4 25 that makes a prop rattle/ chatter . The tempest does not. My merc tech told me it is the nature of this prop because there is so much exhaust being flooded into the blades that it looses its bite at idle and therefore skips and makes that noise/vibration. I have been told by others that have the txp ot4 that it did the same thing on theirs. Other than that it runs like a champ and will push my boat 70mph and still climbing. But I am afraid to go any faster than that.

I thought maybe you were running one of these and I was going to give you some insight on that this was normal with the Txp. But since it does it on all your props I think your tech is in the know more than I LOL Good luck

[EuropeanAM]

<table width="90%" cellspacing=0 cellpadding=0 align=center><tr><td>Quote, originally posted by MET &raquo;</td></tr><tr><td class="quote">He said he would cheat a bit higher idle on the Throttle position sensor and would fix the problem.

</td></tr></table>

Although TPS reading is critically important (as is a CONSISTENT TPS)... any "adjustment" made (there's no adjustable linkage, BTW) would be over-ridden by the PCM.

At keyup, the PCM "learns" the TPS position, and considers that position to be IDLE (then computing where WOT should be, based on the expected range of the TPS).

Idle speed is PCM controlled...

All that being said... if there's a linkage problem, worn bushings, throttle plate cam roller incorrectly adjusted, or a "glitchy" TPS... there's definitely improvement to be had in that area.

Be sure to report back with what's found... always interesting to hear what works in different situations.

[cactusworms]

Thanks Met,

I haven’t had the time lately to work on my motor, but I’m definitely taking notes so when I have the time to focus on mine 250XS I can resolve the issues quickly.

[Tom Rollins]

When it comes to burgers I know what you're talking about, I never eat McWenKing's. We get our beef from a local butcher who raises his own!
I'm thinking about changing the reeds in my Optimax in the spring, peace of mind thing. Provided it doesn't void the warranty, I'll give you a call.