I have a 95 Mercury xri 200 2.5! The problem occurred about a month ago took it to my mechanic (A good one at that). The boat idles and planes off great as well as midrange up to 3800 rpm's! The problem is when you hit 3900 rpm's the boat bogs down if you back off to 3800 it runs perfect again. Here's a list of what's been done since the problem started.
ECU REBUILT BY CDI
NEW FIBER REEDS INSTALLED(found one chipped)
FUEL PRESSURE TESTED HIGH SIDE AND LOW SIDE (3 times)
EVERY IGNITION COMPONENT TESTED
DRAINED THE FUEL ADDED NEW
Anyone else run into a similar problem?

what is tha number of tha ecu?.. should be 823003 1 or A 1... why was ecu "rebuilt"?.. does your mech have access to a known good/untouchrd ecu?.. CDI is 0 and 3 on rebuilt ecu's that I actually know of!.. lots more through network connections.. were tha injectors/fuel rail o-rings serviced/replaced?.. does it die if ya don't back out of it?...was tha low pressure mech. pump checked?...

I have hit problems with the motor wiring harness on these boats. That fuel pressure needs to be tested while on the water.

Need to test the detonation control module. It allows an 8 degree timing advance if the engine is not detonating. Could be malfuntcioning... Or it could be working correctly and it is sensing engine problems

Thanks for the replies! The number on the ecu is 824003 A8 and it was rebuilt because the mechanic thought that might be the problem so it was sent to cdi to be tested and they said it tested bad and sent me another rebuilt one in its place. It does not die if you stay in it just bogs down.yes the low pressure pump was tested as well as the high on the water running at normal operation. Boatwhisperer thanks I will have that checked

best thing ta do with tha det. sensor and module on an older motor is trash it.. if you take it out again put in fresh plugs.. run it around till its good and warm.. throttle it down and let it bog down a few minutes then shut it off with tha key whiles its "boggin'.. immediately pull tha plugs and take a look.. justa note.. jus cause CDI says its good ta go don't make it so.. ie: A8 is a '96 200 ecu, first year with tha pump inside tha silver vst....is yours that type or is tha pump outside tha vst? reason I asked is that there is a small cone shaped filter in tha "U" shaped hose on tha bottom of tha pump that gets over looked a lot and can cause problems....

side note... its always a "second guess" when ya ona computer but its ideas from lotsa folks on here that have seen a lot over tha years....gl

TLW mine is the one with the pump outside the VST and yeah I have already checked that as well as the filter near the schrader valve.I agree there is lots of knowledge right here in TFF. After reading everyone's input and researching the ECU numbers and detonation control module I really think one of the 2 is where my problem lies. I really appreciate all the input and I will keep all of you updated on this and what it ends up being hopefully it will help someone else in the future.

justa a little fyi.. if you can get hold of ANY 824003 ecu. 150, 175, 200 all tha way up ta tha A30 it will work fine for testin'.. truth be known there's not much difference in any of 'em.. found that some 150's run better on 200's than tha 150's.. some 200's run better on 150's/175's and such...fuel maps/circuitry seem ta be a little inconsistent at best..'specially tha early 003's. gl!