Mercrusier 5.o mpi 2004 performance down

S

Smalier

Recruit
Joined
Mar 9, 2011
Messages
4
First post so treat me gently,
I have a 2004 Maxum 2000sr3 with the above engine,the boat has been perfect until last season when after a service by a mercruiser agent the boat has lost 10mph and a lot of accelaration,it runs perfectly and fuel consumption is normal.
The only thing that was done on the service was a injector was faulty so all 8 were serviced.
The boat is always flushed out,cleaned and waxed !!!
Any ideas as the new season approaches ??
Smalier
 
Don S

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Mercrusier 5.o mpi 2004 performance down

Basically, Mercrusier 5.o mpi 2004 doesn't help much since 2004 is only the year of your boat, and may not be for your engine, plus Mercruiser lists nothing by year, only SN. Do you have an engine serial number handy?'

The boat is always flushed out,cleaned and waxed !!!
Click to expand...

While that is a good thing, it does nothing for the engine.

When the injectors were serviced, did the fuel filter get checked for water? and then replaced?
When was the last tuneup. new spark plugs, cap, rotor, etc?
 
S

Smalier

Recruit
Joined
Mar 9, 2011
Messages
4
Re: Mercrusier 5.o mpi 2004 performance down

Hi
Thank you for the replies
The sn is OW 027016
The engine does not rev as high as before although if if prop down a size it will,
the fuel filter,plugs,oil,filter and belt were all changed at the same time as the injector service,according to the invoice no.8 plug had white deposits ( lean burn ) so injectors removed and found to to have incorrect spray pattern although fuel flow ok.
The hull is waxed,the same prop was on the boat and undamaged 48x19 ss lazer have also tried a Mirage 48x17 to check revs.
Regards
Smalier
 
Don S

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Mercrusier 5.o mpi 2004 performance down

Until you get the engine propped to run at the correct WOT rpm, you will not get good performance. If you are below max WOT rpm, then you are lugging the engine. not a good idea. And very hard on your engine.

PS: normally a prop number is stated in dia./pitch. I somehow doubt you have a couple 48" diameter props.
 
Tail_Gunner

Tail_Gunner

Admiral
Joined
Jan 13, 2006
Messages
6,237
Re: Mercrusier 5.o mpi 2004 performance down

Smalier said:
Hi
Thank you for the replies
The sn is OW 027016
The engine does not rev as high as before although if if prop down a size it will,
the fuel filter,plugs,oil,filter and belt were all changed at the same time as the injector service,according to the invoice no.8 plug had white deposits ( lean burn ) so injectors removed and found to to have incorrect spray pattern although fuel flow ok.
The hull is waxed,the same prop was on the boat and undamaged 48x19 ss lazer have also tried a Mirage 48x17 to check revs.
Regards
Smalier
Click to expand...


Does that mean you replaced your injectors due to irregular spray pattern??? Followed by a loss of speed and power.
 
S

Smalier

Recruit
Joined
Mar 9, 2011
Messages
4
Re: Mercrusier 5.o mpi 2004 performance down

Hi
Before the engine was serviced,the engine reved out perfectly,the prop size has not changed,the injectors were serviced not replaced,the plugs were changed at the same time.
can the distributor make a difference even if the engine is running smoothly ?
Otherwise the whole family is on a weight loss program,and they are not heavy now !
Smalier
 
6

6meter

Chief Petty Officer
Joined
May 15, 2010
Messages
525
Re: Mercrusier 5.o mpi 2004 performance down

Smalier said:
the invoice no.8 plug had white deposits ( lean burn ) so injectors removed and found to to have incorrect spray pattern although fuel flow ok.
Click to expand...
Is there a injector spray pattern tester now? New to me.
If it ran good before the service and not after, those that serviced it, muffed something up.
 
D

dannyual767

Petty Officer 1st Class
Joined
May 15, 2010
Messages
273
Re: Mercrusier 5.o mpi 2004 performance down

6meter said:
Is there a injector spray pattern tester now? New to me.
If it ran good before the service and not after, those that serviced it, muffed something up.
Click to expand...

That is where I'd be looking! You're now way down on power and that was the only thing that was changed.
 
D

dannyual767

Petty Officer 1st Class
Joined
May 15, 2010
Messages
273
Re: Mercrusier 5.o mpi 2004 performance down

Smalier, I just reread your original post and you didn't mention if you took the boat back to the place that did the service. Did you or did you at least talk to them about your severe loss of power? "10mph and a lot of accelaration" is huge!
 
S

Smalier

Recruit
Joined
Mar 9, 2011
Messages
4
Re: Mercrusier 5.o mpi 2004 performance down

Thanks for the comments
yes went back to the service centre,full dionostic and no faults.been to another and the same,but he did say the same that a dionostic whilst running and see whats going on !
smalier
 
You must log in or register to reply here.
Top