PLEASE - Need help 01' 225 Optimax

[Onthego]

Extremely hard to start and once started will not idle must keep rpm above normal idle to keep it running. Will not get on plane and only runs about 2400 rpm. replaced plugs but still hard to start. Once started would not idle but was able to get it on plane but only ran about 4000 rpm. restarted engine and it would not get on plane and again only 2400 rpm (about 8 mph). Any suggestions? Does it sound like a reed problem?

[EuropeanAM]

Dennis:

You'll need to check the BASICS:

-INSPECT BELT AND TENSIONER for problems
-Compression test
-Spark Test (on all six cylinders)
-Fuel Quality, Delivery and Pressure Tests (Includes AIR/FUEL Pressure Tests)

Reeds aren't IMPOSSIBLE, but I can tell you that most Optimax engines will start and idle even with reeds damaged on TWO cylinders.

[Onthego]

Belt looks fine and seems to be tight.

All plugs getting fire.

compression check was good

how do I check fuel quality? I added 30 gallons to top off tank before launch and motor ran fine most of the day until this problem started. Fuel getting to rail. will get air/fuel pressure checked today.

Thanks Don

[EuropeanAM]

Fuel "quality" is best checked by connecting a SEPARATE supply of fuel via a 6 gallon portable tank (known good and fresh fuel).

If the problem ceases- you've "disconnected the problem".

Let me know what you come up with for Air and Fuel Pressures.... also monitor to see how rapidly pressures "fall off" once key is turned off (air and fuel pressure should not drop "substantially" within 30 seconds of key-down).

Keep in mind- with the 10 psi differential pressure (Fuel Pressure = Air Pressure + 10 psi), if air pressure is falling, fuel pressure will fall proportionally.

[Onthego]

Don,

Took it in to a Merc mechanic. He found the compressor bad and a reed in #1 had chipped. He did not run a compression check but did run a leak down and said all cylinders had high leak down of 30-50%. He told me a leak down was the best route to go as it is more accurate. He hooked the boat up to a compressor in the shop and the motor still would not crank. Said he would have to go inside to see what the problem was. Also that I was probably looking at purchasing a new motor. Told him to stop where he was and I would get back with him.

[EuropeanAM]

Leakdown of 30-50% is certainly unacceptable. However, this COULD be the result of running the engine with low, or nearly NO air pressure. Carbon builds rapidly, fouling the piston rings, SPARK PLUGS, and direct injectors.

In many cases, it's necessary to REPLACE the spark plugs to get the engine to run, even on "shop air supply".

Based on the leakdown percentages, I would say that removal of the cylinder heads and intake/reed assemblies are in order to determine the cause of high-leakdown numbers (and what an appropriate course of action would be).

I have one with a very similar situation here right now... it received spark plugs, direct injectors cleaned, a set of reeds, and will be de-carbed prior to returning to the customer. In his case, the small pieces of reed appeared to have done negligable levels of damage.

[Onthego]

Don - Thanks for the info. Had him run a compression check and got these numbers (#1 - 82) (#2 - 90) (#3 - 90) (#4 - 90) (#5- 83) (#6 - 85)

Is it possible I'm looking at a new complete power head as well?

May have to stand on the corner with a sign "Retired Marine Needs New Motor"

[EuropeanAM]

Drop me an email.... or give me a call and I'll try to offer you some pointers.

I think there may be some hope for your engine.... possibly.