Reed change lose power?

[croSSed]

Has anyone ever heard of a Mercury V6 losing high-end horsepower by switching to after market reeds? I "upgraded" to carbon fiber reeds awhile ago, and while the engine seems to run better at displacement speeds and seems to have better low-end throttle response, I've lost 2 mph and maybe 300 rpm at WOT. I don't know what else could have caused this. I'm going to check compression tomorrow.

[patchesII]

A reed change can cause a drop in power if the new reeds are too stiff.

[HStream1]

We were doing some extensive Dyno testing in May and June. And when it came to the Reeds we noticed 11HP variance between different thickness and stiffness of Reed materials.

:iagree:
A reed change can cause a drop in power if the new reeds are too stiff.

[XstreamVking]

Someone on here did a reed comparison years ago, it was very informative. Reeds are critical....

[Jay Smith]

Eric is correct too stiff a reed will limit ability of a stock engine to “draw” vapor into intake I use only TDR reeds and a .022” composite reed I do NOT use carbon fiber reed valves on any motor I build , race or recreational for that reason ...JMO

Jay

[XstreamVking]

I just reviewed the reed tests, very interesting.

[Radiant]

Have a link to the reed tests?

[SS Minnow]

Have a link to the reed tests?

https://www.screamandfly.com/search.php?searchid=4961162

[XstreamVking]

I gave up on the search and went google. Typed scream and fly reed tests. https://www.screamandfly.com/archive/index.php/t-206831.html Near the end of the thread

[croSSed]

I gave up on the search and went google. Typed scream and fly reed tests. https://www.screamandfly.com/archive/index.php/t-206831.html Near the end of the thread
That was VERY interesting. I wish I hadn't thrown away my stock steel reeds or I'd swap them and check numbers again.
I have a 2.0L 150 XR2, so the reeds are horizontal. I hate to say it, but the reeds are CCMS reeds. It runs a little better at displacement speeds and "seems" to have better low end throttle response, but the boat is at least 2 mph slower and was turning up 6200-6300. Now I'm only getting 5900. I want my old reeds back!

[nitro_rat]

That was VERY interesting. I wish I hadn't thrown away my stock steel reeds or I'd swap them and check numbers again.
I have a 2.0L 150 XR2, so the reeds are horizontal. I hate to say it, but the reeds are CCMS reeds. It runs a little better at displacement speeds and "seems" to have better low end throttle response, but the boat is at least 2 mph slower and was turning up 6200-6300 (tel:6200-6300). Now I'm only getting 5900. I want my old reeds back!

2.0 150 XR2 is a vertical front motor...

[bigbluechevy454]

Has anyone ever heard of a Mercury V6 losing high-end horsepower by switching to after market reeds? I "upgraded" to carbon fiber reeds awhile ago, and while the engine seems to run better at displacement speeds and seems to have better low-end throttle response, I've lost 2 mph and maybe 300 rpm at WOT. I don't know what else could have caused this. I'm going to check compression tomorrow.. Please don’t take this as I’m being a smart a$$. Just want to add my experiences. Unless you tested and changed reeds. ASAP. Like I. 30 min went right back I. To test. Lots of other variables could affect your performance. Weather waves etc.

[croSSed]

2.0 150 XR2 is a vertical front motor...
You are correct. Sorry. Semantics problem. As to the other comment from bigblue454chevy, I get it. But, you're full of it. I've operated this motor on this boat with this set-up for at least 10 years. It doesn't run like it used to, BUT...I haven't taken a compression reading yet.

[ChrisCarsonMarine]

Give a call so we can figure this out,Chris,305-394-3354

[Motv18]

Was their a change in temp and humidity from the higher numbers. 90-100 temp can rob 500 rpm vs. 50-70. Some older carb motors even have cold hot stop levers so you don’t over run when it’s cool out.

[croSSed]

Was their a change in temp and humidity from the higher numbers. 90-100 temp can rob 500 rpm vs. 50-70. Some older carb motors even have cold hot stop levers so you don’t over run when it’s cool out.
Nope.
Chris, I'll give a call tomorrow probably late in the day. West Coast time and all. Thanks.

[SS Minnow]

https://www.screamandfly.com/search.php?searchid=4961162
For some reason the above link leads to nothing, sorry about that. It worked before. Will try again.

https://www.screamandfly.com/search.php?searchid=4968856


ETA, that works much better. Must of just copied and pasted wrong link.

[croSSed]

BTW, here are my comp readings: #1-120, #2-128, #3-122, #4-130,#5-119, #6-129. Not great, but still within 10%.
SS Minnow - The hyperlink above doesn't work. Sorry.

[Dave S]

reed stops and Breck point.....Where the reed starts bending.......Also plst reeds are stiffer .... than ss....jmo....

[Dave S]

your comp # are with range......

[Merc 2.5]

Just grab a thinner set from chris and see how it goes , I'm sure i got steel reeds that was n good shape when took off ( use at own risk) I'll check if ur interested

[croSSed]

Uh oh.
My engine just started missing. It has been backfiring/sneezing through the top carb on the starboard side at idle. What could this be?

[Merc 2.5]

A miss or pick up tube stopped up b my guess , unless u broke a reed I highly doubt the reeds is sneeze issue, do u have a spark tester? Miss at idle or what rpm? Or from idle to wot

[Motv18]

On the other hand that sucks, but might have discovered the real power issue.

Could also be unrelated

[croSSed]

A miss or pick up tube stopped up b my guess , unless u broke a reed I highly doubt the reeds is sneeze issue, do u have a spark tester? Miss at idle or what rpm? Or from idle to wot
I have a multimeter. Not sure how to use it in a case like this, though. I can also tell you that while I was running it in my driveway I pulled the #1 plug wire from the plug to see how differently it would run, and got grounded GOOD. Seems it isn't a spark issue. I can't make it replicate the problem in the driveway. It needs to be under load. It sneezes back through carb at dead idle in gear, 700 rpm. I doubt it's a reed, too. If it was a reed it'd be leaking comp back through on every up stroke of #1 piston.
No matter; I hope to find out tomorrow what the prob is as the reed block is coming out to put new reeds in.
:cool:

[tlwjkw]

pull cowl and start after dark...

[croSSed]

pull cowl and start after dark...
Hehe. The neighbors will LOVE that - smoke and noise...What would I be looking for? Flames in a carb throat?

[RSWORDS]

Lean sneeze? Where are your mixture screws?

[croSSed]

Lean sneeze? Where are your mixture screws?
The thing is, the carbs haven't been touched. Why would it suddenly start leaning out? Plugged idle jet, vacuum leak... Those seem like the only real possibilities.

[tlwjkw]

.What would I be looking for?

move a grounded screw driver around all tha wirin', especially tha coils and plug wires...

[RSWORDS]

The thing is, the carbs haven't been touched. Why would it suddenly start leaning out? Plugged idle jet, vacuum leak... Those seem like the only real possibilities.

Very possible

[SS Minnow]

BTW, here are my comp readings: #1-120, #2-128, #3-122, #4-130,#5-119, #6-129. Not great, but still within 10%.
SS Minnow - The hyperlink above doesn't work. Sorry.
Damn, just seen this. I will try one more time, just differently. Here goes:

https://www.screamandfly.com/showthread.php?206669-The-Reed-test-begins&highlight=reed+test

https://www.screamandfly.com/showthread.php?208692-Reed-Test-results-Here-now&highlight=reed+test

https://www.screamandfly.com/showthread.php?208740-OMC-reed-test-results-(non-race)&highlight=reed+test

https://www.screamandfly.com/showthread.php?200572-REED-TEST-The-Velocity-Fueling-US-valve-guy-is-back-States-a-45-HP-gain&highlight=reed+test

https://www.screamandfly.com/showthread.php?202066-More-Information-on-the-quot-REED-quot-test-we-ll-be-doing&highlight=reed+test


Hopefully that works as they are good reads, pun intended.

[Chaz]

After you find one of the vacuum lines fell off .. come back and tell us what color it is ... :thumbsup:

[Capt.Insane-o]

Make sure the throttle plates are closed at idle. Anytime you disturb a carb you should check and make sure the "synch" wasn't upset.

[croSSed]

Well folks, I think I found the problem. The reed block gasket on the top, starboard side had slid in and there was a vacuum leak on the #1 cylinder at that point. I took apart the whole reed assembly to check it out, and put it back together with new gaskets. Hopefully, tomorrow I'll get to test run it.

[Captain75]

Well folks, I think I found the problem. The reed block gasket on the top, starboard side had slid in and there was a vacuum leak on the #1 cylinder at that point. I took apart the whole reed assembly to check it out, and put it back together with new gaskets. Hopefully, tomorrow I'll get to test run it.
Great! Glad you found the problem!