225EFI on Gambler 206SS Off Idle Issues

[ttmott]

Just finished rigging a 225 EFI Merc on my Gambler 206SS and having issues getting the motor to pull the boat out of the hole and on plane. The motor is fresh with new power head and solid mounts installed. We took 5 degrees out of the transom and installed the jack plate so there is -2 inches below and +4 inches above keel travel. So, testing props from 21 to 27 pitch; with the 21 the boat fires right out of the hole but with the 25 and above the engine boggs and stumbles and will not pull the boat out of the hole. If I set the engine way up on the jack plate and not trimmed under the engine pulls right out of the hole but it's a hairy and rather uncontrolled launch.
The only thing I can come up with is the idle exhaust port is below the water and will not allow the motor to come off idle. Anybody have experience or information on this? Thanks for the help!

[ttmott]

Well, I thought I'd bounce this up to see if any help at all.
Put a 26 Fury on and if the motor was jacked all the way up and not trimmed under it pulled the hull out no problem but a bit of a wild launch.
Motor up on jack plate and trimmed under (idle relief port just under water and would not come up on revs until trimmed up then again a rather wild launch.
Motor down on the jack plate (idle relief port below water) and the motor would not come up on revs at all.

Only thing we can come up with is the water level cannot be up to the relief port. Any technical help here or knowledge?
Searching and seems Gambler hulls are transom low in the water, comparatively.....

[XstreamVking]

I know it sounds un related, but I have a 225 EFI 2001 model. Had the same problem on my flats boat. Motor ran great at cruise and top end. Ended up being the return filter screen at the vst tank had gunk in it and was causing hi fuel pressure. Too much fuel at low r's and it would bog with a 25p prop. Didn't bother it when the motor could spool up easy from idle. Like when jacked up. May or may not be your problem. Just my 2cts.

[ttmott]

Thanks, I'll pull it and take a look. TPS is in spec BTW.
Leave no stone unturned at this point....

[XstreamVking]

It was strange, just check the fuel pressure at the schaeder valve for 38#s I believe. Mine was pushing 42#s before cleaning the screen. Seems the fuel can't return from the injectors and floods them. These motors are so thirsty I didn't notice the xtra fuel consumption.

[ttmott]

It was strange, just check the fuel pressure at the schaeder valve for 38#s I believe. Mine was pushing 42#s before cleaning the screen. Seems the fuel can't return from the injectors and floods them. These motors are so thirsty I didn't notice the xtra fuel consumption.

Easier yet - thanks!

[LethalGambler]

Hey,

Old thread, but I also have a Gambler 206SS (Ski Boat, not the bass boat) anyway, I have a 225 Carb Merc on it and a bad 21p prop. Check the boat for WET FOAM! Mine is soaked and wouldn't plane with a 24p choper on it. Foam is drenched. Perhaps it's not a motor issue.

-Alex