225 optimax loss of power

[Keystonekiller]

2001 225 optimax
S/n 0T371389
Little bit of history. Engine was an opti-pop. It popped in 2002 with 70is hours and merc put a new powerhead on it. Has a little under 200 hrs now. This is all i know about the engine.

Now the problem. Noticed a few months back it was sluggish out of the hole. Real slow. 55 mph all it had at 4500 rpm. No warning beeps. Idles fine doesnt miss or shutter any. Took the fuel filter off and low and behold chunks of brown stuff. Took the gas tank out and washed it and let dry.replaced the fuel hose from the tank to the purge pump including prime bulb and filter. While replacing and cleaning the fuel system never found the brown chunk problem.

Ive noticed it runs a lil smoother and start ups are a lil easier but still slow out of the hole. I put the hot foot down to wot and there is a big delay before she starts to spin then its like 1/2 power out of the hole. No sputtering or anyindication of missing or anything just slow. I can get it to 4500 rpms or so and thats it.

I replaced the plugs mid summer just to replace them had no issues just doing preventative maint. I run only amsoil synthetic. Use only 100% real gas with stabil and quick clean.

Im at a lost and any help or suggestions would be awesome.

Thanks for your time bbc-ers.

[grybrd]

When you found the chunks, did you do all of the recommended fuel system updates or just the fuel line, primer bulb, and filter?

http://www.bbcboards.net/showthread.php?t=22490

[Keystonekiller]

Thanks grybrd.
Just read the link. The grey hose looked familiar. Went to the garage and that grey hose crimped to the primer bulb i just replaced. I cut it open and the picture in the post is right on. Holy $&!+. I know what my problem is. Purge pump and another filter coming soon.

[Keystonekiller]

Update:
Rebuilt the pulse pump, replaced the fuel filter and drained vst tank for inspection today. Pulse pump looked ok. No brown chunks or tears in the diaphram. Took it to the ramp to test drive. Hole shot was a lil better but not 100% once on plane the power came on a little quicker but once again not 100%. I was able to hit 5000 rpms but nothing past it. Puurs like a kitten. Doesnt seem like its missing.

Any more ideas?
Thanks in advance for any help

[Savage]

Did the boat, motor, and current prop combination ever achieve 5700 RPM @ WOT for you?

[12many]

did u dissasemble vst, fuel pumps have tiny screens on bottom those can gum up? ive opened a few vst tanks that were clean but pumps had gunk.

and does your warning horn work. does it beep at key on?

[Keystonekiller]

Did the boat, motor, and current prop combination ever achieve 5700 RPM @ WOT for you?

Yes sir. Top speed dances around 70ish mph at 5700 rpm. Had it at 72mph one time.

[Keystonekiller]

did u dissasemble vst, fuel pumps have tiny screens on bottom those can gum up? ive opened a few vst tanks that were clean but pumps had gunk.

and does your warning horn work. does it beep at key on?

I did not disassemble the vst. I drained it. I thought about opening it up but wasnt sure if there was a gasket or anything i needed for it. Yes i get a beep at key on before i crank over the engine.

[mdtritn21]

You have to clean the VST not drain it.

[grout-scout]

You have to clean the VST not drain it.

Do you mean disassemble clean or just clean the gunk out of the bottom? I'm wondering if my boat is suffering from the same thing. Is there a sticky on this?

[Keystonekiller]

You have to clean the VST not drain it.

I will take it apart after work today. Thanks

[EuropeanAM]

All of those items in the Performance Problems- Check your Fuel Lines FIRST thread must be done AT THE SAME TIME, don't piece-meal or split items up, or you may be chasing the problems for a long time.

[Keystonekiller]

All of those items in the Performance Problems- Check your Fuel Lines FIRST thread must be done AT THE SAME TIME, don't piece-meal or split items up, or you may be chasing the problems for a long time.

No where in the post did it say to clean or dissassemble the vst tank. Did it anyway and it was clean. Im starting to think tps. Im positive the brown chunk( deteriated hose) problem is resolved. Still same issue. Ive turned alot of wrenches in my life professionally and hobbyist. Be honest the engineers at mercury should be shot....frustration is building

[Savage]

No where in the post did it say to clean or dissassemble the vst tank. Did it anyway and it was clean. Im starting to think tps. Im positive the brown chunk( deteriated hose) problem is resolved. Still same issue. Ive turned alot of wrenches in my life professionally and hobbyist. Be honest the engineers at mercury should be shot....frustration is building

Why do you think "the engineers at mercury should be shot"?

[Keystonekiller]

1. Fuel should be filtered before enters any part of the components. 2. Grey hose red writing. 3. Compressor for direct injection. When the compressor fails and sends junk to the fuel rail why not have a filter? Then again why a compressor? 4. Merc says to add race oil in the gas tank for optimax. Optimax suppose to be low oil consumption. Ever look up the price for race oil? 5. Tps is a joke. Too many moving parts allready under a cramped cowling multiple brackets and rods. Simplify it.

Just want my engine to run right. Alot of money for this engine with only 187 hours. Direct injection does not require 1000 components to work correctly.

[Savage]

1. Fuel should be filtered before enters any part of the components. 2. Grey hose red writing. 3. Compressor for direct injection. When the compressor fails and sends junk to the fuel rail why not have a filter? Then again why a compressor? 4. Merc says to add race oil in the gas tank for optimax. Optimax suppose to be low oil consumption. Ever look up the price for race oil? 5. Tps is a joke. Too many moving parts allready under a cramped cowling multiple brackets and rods. Simplify it.

Just want my engine to run right. Alot of money for this engine with only 187 hours. Direct injection does not require 1000 components to work correctly.

Mercury never said for you to "add race oil in the gas tank for Optimax". It would be illegal to alter the emissions.

[Keystonekiller]

http://www.bbcboards.net/showthread.php?t=578178

Brought this up at a local marina. The mercury certified tech said it was true but he hasnt heard of premium plus. Mercury advised him that race oil was preferred.

Do you think im making this up savage?

[Savage]

Your ranting like you have to do it, all I'm saying is that adding oil to the fuel is NOT in your owners manual. I also can't believe the a Mercury Certified Technician "hasnt heard of Premium Plus".


I suggest you check the following:

Air/Fuel Pressure (at idle, under acceleration, and 5/10/15 seconds after motor shutdown). Make sure that you check pressures, together at the same time, with dual glycerin filled gauges.

Perform a TPS voltage Sweep Test (on the Computer Diagnostic System) since you seem to believe that something is wrong with it.

[Keystonekiller]

Let me clarify. Nnever heard of mixing premium plus in the tank. Figure it would make sense if you read the link.

Scroll up......you asked and i replied. Thanks for your help anyway

[OldTimer57]

I think Don suggested a 150:1 ratio adding oil to the tank to provide minimal lubrication to the injectors.