2006 225HP Optimax DFI 3.0L will not go over 4400 RPM's before and after rebuild

Jcullen87

Cadet
Joined
May 8, 2011
Messages
17
First of all I want to thank all who contribute to these forums. You have helped me immensely throughout the years through some truly frustrating and puzzling issues. And now, I have one that tops them all so far, and hope you can help shed some light.

The issue started last season. I was topping out at 4400 RPM's as I am now, then I had a sleeve in the cylinder slip on me. I had the engine rebuilt and the sleeve is now pinned. Here is a list of what has been replaced and I am still having the same issue.

All bearings in the engine and a new piston in the cylinder that had the sleeve turn
All fuel and air injectors that were out of spec were replaced - the rest were cleaned.
Oil pump
Air Filter
Impeller
water pump gaskets
gear oil
130 degree Thermostats (both have been tested and pop at 130 degrees)
Fuel was drained and has been replaced with non ethanol fuel.
Fuel pump seal
Carbon Fiber reeds replaced the old metal reeds
fuel line and bubble
Battery is a brand new redtop


What has been tested:

Compression 100-105 on all 6 cylinders
Cylinder miss fire test - all were firing
Air/Fuel compression read 84 and 94
water PSI is at 2.2 at idle and around 10-15 when at 4400 RPM
Temps are good (get up to 130-134 then cools down to 118 or so - had a problem where there was something stuck in the poppet on one thermostat so it was open all the time but has been corrected)
Throttle, hot foot, and butterfly have been checked.


Boat is currently in break in period with about 90 minutes on the motor - it had 580 before the rebuild.

I have kept the trim down all the way and only get 4200 RPM. Raising the trim (only did it once) gets me to 4400-4500 @ about 44 MPH
Before these problems started the boat ran normal and got to about 65 MPH
I talked to Mark at marksprops.com and he said theres no way it is a prop problem, it is an engine issue.

My mechanic's reader is throwing two errors:

Oil Lvl ckt Hi
Sea temp ckt Hi

I am not a mechanic, but am mechanically inclined can do most small things myself. I'm sure I don't have to tell you the frustration and stress this has caused thus far, so I won't. I appreciate any help you all can provide.
 

Jcullen87

Cadet
Joined
May 8, 2011
Messages
17
Had another thought I thought I better add. I get out of the hole fine. The problem seems to be only at WOT.
 

flyingscott

Fleet Admiral
Joined
Apr 8, 2014
Messages
7,985
You need to find what is causing the 2 errors. What did the mechanic say about those
 

Jcullen87

Cadet
Joined
May 8, 2011
Messages
17
He looked in the DDT books but it didn't really say a lot.

sea temp ckt hi - has to do with the transducer/depth finder built in to the boat. There is a short or something but would not cause the RPM issue.
As far as oil lvl ckt hi - The books were not specific and I haven't been able to find anything solid online. I know that the oil reservoir is full and the oil pump is brand new. The oil tank inside my boat is full now but threw the same erros with only 1 inch of oil in it. Also the tank doesn't have a sensor. Mechani said he would make some calls to see if he could find out more.
 

Jcullen87

Cadet
Joined
May 8, 2011
Messages
17
We are taking the boat to the local lake tomorrow evening to run the DDT while on the water. I have been scouring through forum after forum looking for answers and right now thinking it may be an injector problem, but really still have no idea.

We will test the air/fuel pressure at WOT and see what she says as well. If anyone thinks of anything else I should have the mechanic check while we are out there I am all ears.
 

Jcullen87

Cadet
Joined
May 8, 2011
Messages
17
I should have added above that the prop says 25P but when I bought it the previous owner said it had been re-pitched to a 23
 

Jcullen87

Cadet
Joined
May 8, 2011
Messages
17
So, after taking it to the lake. My mechanic hooked the DDT up and the only thing that wasn't reading correctly was that the TPS was at 9V at idle and 4.95 at WOT. They should actually be this:

Idle 0.4 ? 1.3 VDC
Wide Open Throttle 4.0 ? 4.7 VDC

So right now it is looking like it is the TPS. New one has been ordered. If it is not the TPS then I am not sure where to look next. ECM maybe?

I will post the results next week after the part is replaced and I can get it on the water.
 

Teamster

Lieutenant Commander
Joined
Nov 8, 2010
Messages
1,923
What size starting battery are you using?

I've been told Opti's like voltage, And a group 29 is minimum,
most people I know with them run group 31's,......
 

Jcullen87

Cadet
Joined
May 8, 2011
Messages
17
Anyone else run the same battery that can chime in on performance?

I always show good voltage as far as battery goes. No dips or surges etc.
 

Jcullen87

Cadet
Joined
May 8, 2011
Messages
17
So. New TPS came in today. Went up to 5200 RPM.
Which is great. Topped out at around 55 or 56. This is lower than I'm used to but take some weight off and proper pitch and it should be fixed.

However Now when in neutral I'm at 1000 RPM. Checking throttle linkage etc tomorrow.
 

Jcullen87

Cadet
Joined
May 8, 2011
Messages
17
So, I adjusted the stop barrel and still had the same high RPM issue. I couldn't see any problems in the throttle linkage. Then something happened while on the lake.

I made a hard turn because I had almost driven right past the creek arm I was looking for...the RPM's rev up and I release the hot foot. I start getting messages on the smart craft. "Check Engine, TPS ERROR" but the boat still operates fine at all speeds except the high RPM at idle...I shut down the motor and turn it back on...error is still there. So I decided to shut it down for a longer period of time...after 30 minutes I turn it on...error is gone....and no more high RPM's at idle. It is like the computer had to adjust things for the new TPS if that's a thing. Like it was still working off the way the bad TPS was functioning. So for now that issues is resolved...I guess?

New TPS did really improve things. I am getting 55 or 56 mph at WOT. It used to be 65 back before all this sh*t started. Not sure why this is...Other than that the only remaining issue is that when turning right I loose some power and the RPM's increase. If I make a hard right the RPM's go up quickly and I lose all my turning power and have to release my hotfoot pretty quickly.

Anyone know why this is? The boat is about 200 lbs under max with just me in it and all my gear and a buddies gear, batteries, etc. I am thinking it might be a combination of weight (maybe even distribution of) and maybe a prop...although the prop looks great. It does have a few dings in it. The prop says 25 on it but it had been re-pitched before I bought it and he said he though it was a 23 now. I will try to post a pic if I can remember to when I get home.

I am almost there!!!!! But at least I am fishing again. Caught a boat load last weekend fishing the transition areas between 14 foot ditches and spawning flats. They were moving up! I already missed the start of the tournament season, but there's always next year. I hope at least for others searching with similar issues that this might help them. TPS' can go bad and never say anything on the computer...check those voltages!

Please post your thoughts about the turn issues.

Thanks!
 

Teamster

Lieutenant Commander
Joined
Nov 8, 2010
Messages
1,923
Sounds like your throttle cable is getting bound up somewhere and pulled wide open when you turn the motor?
 

Jcullen87

Cadet
Joined
May 8, 2011
Messages
17
I will take a look at that, but after a weekend on the water it feels like a weight distribution problem of sorts.
 
Top