225 EFI Mercury that won't turn more than 4600-4800 RPM's
Ser# 0G914209 1999 225 EFI
just had the injectors cleaned and replaced the reeds with Chris Carson reeds and it still won't turn more than 4800 rpm's I've checked the coils they seem to be fine I've run 4 different props on it and nothing changes it's getting full Throttle butterflies are opening all the way, could it be the stator? Any help would be greatly appreciated thank you
Are the reeds installed correctly?
Did this engine reach normal WOT rpm before the injectors were cleaned (who cleaned them) and reeds were changed?
_______
Phil
'09 Hewescraft ProV
'09 150 Optimax
Check the alternator. Sounds like it could be the problem. Try it and see. Measure the voltage while running at the battery and see how many volts you get. If you don't have at least 13 plus volts ( that is just an estimate i don't know the actual value ) you are not getting enough power to operate the electrical components that supply the injectors, sensors and coils etc. I say this because i had a belt break on the same motor and it did exactly what you are describing. Just trying to help :)
Brucatofis did the injectors yes reeds where done right alternator working right last fall I had run some injector cleaner though it and after running around the lake 15-20 minutes it would clear up and turn 5600-5700 rpm's and would run good tell it sat for a few days then I would have to start all over again with the cleaner, there's not much else it could be is the trigger or stator I'm pulling my hair out over this
Check your fuel lines, go to FAQ at top of this forum, need to have the newer fuel lines. Might want to clean/drain your gas tank
Keith Broussard Caney Lake, Louisiana
2000 TR21 2000 Mercury 250 Pro XB OG980775 14" hydro plate
Many RPM'S could you turn BEFORE the reeds were replaced and the injectors were cleaned?
It would turn 5600 w/4 blade 25p trophy
Are you currently using that prop?
I was before I sent it off to Marks prop to have it reworked
Steve, try using that same 25p prop for comparison. The 221 champion hull with a 225 and any bigger prop over 25p just won't respond well. Actually, a 24p would be a better fit for that boat/motor combo.
I ran a 24p tempest plus today was able to get 4900 rpm's out of it there is something definitely wrong with the motor just need to find out what, injectors have been cleaned, reeds have been replaced, fuel lines replaced, when it was in the shop they said the comp, was good but it had a lot of exhaust while running it in the tank I'm ready to give up on it so if anyone has any more ideas I'd love to hear them I'm willing to try anything at this point please very desperate
Fuel pressure and TPS check good? What about compression?
5fishon - I've struggled with the 4800 RPM problem for years on a '97 225EFI. Replaced reeds, cleaned injectors, checked fuel pressure & compression, changed ECU's, electrical etc. Had a reputable Merc tech look at it last year. He said the powerhead gasket was leaking and the spray was restricting the exhaust. Board members here thought it wouldn't make a difference. Haven't tried changing the gasket yet, but if I do,that will be my last attempt my last attempt. If it fails, I'm looking for a nice used Opti. Best of luck, I'll be watching this thread.
Wilbur, OMG thank you nice to know someone else has had this problem also this thing is driving me nuts would yours once in a while clean up and run 5600 rpm's, I believe we are going to check the tuner next I have noticed that if I feather back a little on the hot foot it will run better but than when I get back on it it acts like it's choking it's self out
I had the same issue with my 2001 Merc 225 EFI 2 years ago. In and out of the shop would not turn 4 blade PT prop more than 5200. Last time in changed ECM's and sent Mark my prop to cup and repitch. After all that was able to run 5600 rpms and ran strong. So, not sure if it was the prop or ecm's or both.
Cheap item for you to try... and yes, I've seen it make a difference.
On the coil plate, add TWO (10) gauge REDUNDANT GROUNDS.
First one to the right-top 8mm head screw (where CDM grounds are), second one to the lower ECU "right bottom screw" (likely is a ground there now, already).
Loop the upper wire OVER the top of the block, and then install a ring-terminal so it terminates at the same bolt the battery NEG. cable is attached to.
Loop the LOWER wire UNDER the STB bank of cylinder, and then install a ring-terminal so it terminates at the same bolt the battery NEG. cable is attached to.
When done... go run it and see if there's any difference.
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
Don, do you happen to have some pics to show of this grounding modification?
Last edited by khart; 04-30-2017 at 07:01 AM.
Unfortunately not. Pretty simple, though.Originally Posted by khart
Dual Mercury Master Technician- for Mercury Outboards, Mercruiser and Mercury Racing at European Marine in Greenville, SC.
Still consider myself a "Marine Apprentice" after 47 years (learn something new every day).
Mercury Parts, Mercury Outboards, Smartcraft & Accessories, Injector Service, TDR Reeds- BBC Sponsor
Don, Is there holes already in the coil plate or do you have to drill holes to connect the ground wire?
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