I have a 97-2000 model merc 200 efi that had a new piston installed this year. Overheated and melted the #3 piston. Got everything back together with new parts and gaskets compression is only 5 lbs off the other 5. Runs like a top out of the water and in neutral. Other that it idles a little high between 1200 and 1400. As soon as you put it in gear it drops to 800 rpm.
The main issue I have is it does not want to plane out. We can remove the cowl and mess with it and usually get it to run around 3700 rpm. Which is about 25 mph on my boat which is fast enough to go fish but it also takes it a minute to get up to that rpm. It goes from idle to 2500-3000 rpm pretty easy but then Boggs down like a weedeater when you give it to much to quick. You have to back the throttle off and it will slowly pick back up when you find the sweet spot. I've tried just about everything and am at a loss it's like chasing a ghost.
Compression is between 115-121 on all 6
Fire on all plugs
Plugs are correct for motor I believe
New plug wires
New mechanical fuel pump
New electric pump in vst with new gasket
All new houses from tank forward
Non ethanol fuel used every time with seafoam every tank
Use quicksliver 2 stroke oil
New water pump hous in ng and impeller
New rings on all pistons
New head gaskets
Injectors cleaned and tested
Has 2 water fuel sep new filters on both
New fuel filter on motor
New stator
I am looking for some help here guys let me know if you've had similar issues please
Thanks in advance.
The main issue I have is it does not want to plane out. We can remove the cowl and mess with it and usually get it to run around 3700 rpm. Which is about 25 mph on my boat which is fast enough to go fish but it also takes it a minute to get up to that rpm. It goes from idle to 2500-3000 rpm pretty easy but then Boggs down like a weedeater when you give it to much to quick. You have to back the throttle off and it will slowly pick back up when you find the sweet spot. I've tried just about everything and am at a loss it's like chasing a ghost.
Compression is between 115-121 on all 6
Fire on all plugs
Plugs are correct for motor I believe
New plug wires
New mechanical fuel pump
New electric pump in vst with new gasket
All new houses from tank forward
Non ethanol fuel used every time with seafoam every tank
Use quicksliver 2 stroke oil
New water pump hous in ng and impeller
New rings on all pistons
New head gaskets
Injectors cleaned and tested
Has 2 water fuel sep new filters on both
New fuel filter on motor
New stator
I am looking for some help here guys let me know if you've had similar issues please
Thanks in advance.
