optimax 225 hard start/stall

afishinado21

Cadet
Joined
May 2, 2004
Messages
11
i'm having a problem with my 2000 225 Optimax s/n: OT019377, purchased new in 2000. Every year, during spring startup I change NGK plugs, air filter, fuel filter, lower unit oil, etc... Also replaced my batteries for the first time in 5 years. Was running dual 680 MCA Starting batteries installed by the dealer. Purchased dual West Marine brand 665 MCA as replacement. I boat in the LI Sound (10% Ethanol) region.<br /><br />Initially the motor started up very quickly and easily, ran for a 5-10 minutes, then stops. Tried to startup again, this time it barely catches then stalls. Continue trying multiple times with similar result barely catches and dies. Then, all of a sudden, motor starts strong with no issue, all seems normal. It'll run anywhere from 1 minute to 15 minutes and beyond then again just stops. Same cycle all over again of barely catching/stalling until it starts normally. <br /><br />Even with the above symptoms, I was able to go out last week and run for a full 20-30 minutes, various speeds without an issue. Tried going out again the other day, slowly moving forward up the creek, when the motor started shaking and running very rough like it was about to stall. This time the Check Engine Light comes on with no audible alarm. Try to limp at minimum to the nearest dock when all of a sudden everything is back to normal, RPMs come back and motor is operating normally. On my way back to my slip it again starts to run rough, check engine light comes on with no audible alarms. I'm able to make it back but unable to start the engine normally after multiple trys.<br /><br />I've checked the basics like spark plug wire and fuel filter. No water in filter, all else looks fine but then again I'm not sure what I'm looking for. I have to wait until mid June for a certified Optimax repair shop be able to look at the engine.<br /><br />Anyone out there come across a similar issue or have any ideas on would cause this intermittant problem? Could one of the new plugs be bad? Spark plug wire is bad? Fuel problem? New battery issue?<br /><br />Any help is greatly appreciated. Thanks...
 

uaw9fan

Petty Officer 2nd Class
Joined
Oct 25, 2005
Messages
112
Re: optimax 225 hard start/stall

Are you running with the battery switch in the both position? The minimum CCA battery for this engine is 800 CCA which is equal to about 1000 MCA.The batteries you just installed are around 525 CCA which is not enough with it on one battery, but on both the CCA's are added making it enough. I would try to run it in the both position to see if the problem goes away. If it does I would buy some better batteries, make sure they are starting batteries and not deep cycle. <br />My .02 for now <br />Good Luck
 

afishinado21

Cadet
Joined
May 2, 2004
Messages
11
Re: optimax 225 hard start/stall

thanks for the reply... I am running the battery switch in the BOTH position.<br /><br />The reason I went with these 665 Starting batteries is cause for 5 years I was running the dealer installed 680 MCA batteries with no issues. The next size up, 800 MCA, seemed like overkill. I've already inquired about exchanging 665 batteries for stronger ones to bring the batteries to spec.<br /><br />I thought battery issue may be the cause but then why would the motor start normally after 5-10 weak/failed starts. Logic indicates the battery is weaker after numerous false starts.<br /><br />Seems to me the issue will be another electrical or fuel related problem.
 

KCLOST

Commander
Joined
Jun 22, 2002
Messages
2,095
Re: optimax 225 hard start/stall

Sounds like you have a spark problem...<br /><br />Try to check the spark when the problem occurs...<br />Could be the ECU...
 

afishinado21

Cadet
Joined
May 2, 2004
Messages
11
Re: optimax 225 hard start/stall

Update... Since motor was running fine all of last season I thought the problem maybe related to a bad component changed this spring. I put back last year’s plugs and again checked the fuel filter for water or debris but everything look normal. <br /><br />Same problem came up after 15 minutes of idling, turning off and restarting... all of a sudden engine goes from idling normally then dies. Restart may happen right away or take a few tries of barely catching but eventually starts strong without any issues.<br /><br />After speaking with mechanics in my yard and with Seatow I think the problem is fuel related, more specifically Ethanol related. A seatow captain explained to me that the ethanol in the gas is separating. This is especially true for boats laid up 4-5 months during the winter with tanks topped off. The engine runs fine until it picks up the separated ethanol, then stalls. After a few restart attempts, eventually good gas gets through and everything operates normally until... <br /><br />In my area, Seatow has had their spring towing calls increase exponentially. People call saying the engine just died. They don't even bother troubleshooting the problem, just tow, because they know its ethanol related. Its a problem that can effect all marine engines.<br /><br />Anyone have suggestions on best way to get through this issue. Is there a stabilizer that can help? Is draining the tank (100 gal) the only option? Thanks...
 

KCLOST

Commander
Joined
Jun 22, 2002
Messages
2,095
Re: optimax 225 hard start/stall

Well, if you are sure about the problem, I'd get the gas out of there and start fresh... And never go with ethanol blend again..<br /><br />Let us know... I've never used that blend so have no experience....
 

gss036

Commander
Joined
Jan 18, 2003
Messages
2,914
Re: optimax 225 hard start/stall

If you have access to a couple of portable 6 gal cans, I would try fresh fuel and see what happens. Even with the present hook up, have you tried pumping the primer bulb when it starts acting up? Does the bulb pump back up easy or is it sucking itself flat?<br />I am not familiar with opti's, but if the check engine is coming on, then there must be a trouble code stored somewhere.
 

andy6374

Lieutenant Commander
Joined
Aug 4, 2005
Messages
1,617
Re: optimax 225 hard start/stall

Originally posted by KCLOST:<br /> Well, if you are sure about the problem, I'd get the gas out of there and start fresh... And never go with ethanol blend again..<br /><br />
We have no choice up here in the northeast, a 10% ethanol blend is all we've got now.
 

afishinado21

Cadet
Joined
May 2, 2004
Messages
11
Re: optimax 225 hard start/stall

KCLOST: Unfortunately, ethanol blend is the only gas available in the Long Island Sound area as of last summer. Mercury says up to 10% Ethanol is acceptable and its been working fine. I never knew about this "accelerated Phase separation issue in marine environments" until reading all the recent BEWARE articles form BoatUS, Brewers yacht yards, etc... since more and more states along the east coast will be switching to ethanol blend this year.<br /><br />Gary: The bulb does not go flat and is always full of fuel.<br />The opti does store error codes but I have to wait until June to get the boat to a certified OPTI repair center. I wanted to try to eliminate all other possibilities beforehand.<br />Great idea with regards to the portable tanks. This is something I hadn't thought of since the fuel line is "hard wired" to the engine. I will try to get my hands on a couple of tanks to see if the problem goes away. If it continues then dealer is my only option. Will keep updating.<br /><br />thanks guys.
 

KCLOST

Commander
Joined
Jun 22, 2002
Messages
2,095
Re: optimax 225 hard start/stall

I understand, didn't mean to come accross as a critic...<br /><br />Surely there is something out there that is made for stabilizing the ethanol blend... Maybe stabil will do the trick...
 

Jan Z

Seaman Apprentice
Joined
Sep 15, 2005
Messages
49
Re: optimax 225 hard start/stall

Long story short here. I'm going through fuel related problems with a Yamaha and they are advising the ten micron water fuel filter, the full time use of an enzyme based fuel stabilizer (Like Star Tron) and ring free at 1 oz per ten gallons. The moisture in the fuel attractec by the ethanol is causing corrosion in the carbs and clogging the low end jets.<br /><br />E10 sucks.
 

rocketswhaler

Recruit
Joined
Jun 5, 2006
Messages
5
Re: optimax 225 hard start/stall

On Merc Marine web site is an excellent article about the new ethanol and the separation issue. There is no way, according to the web site, to address the problem once it has happened other than to drain the tank completely and fill with fresh gas. Preventing the problem is different. The web site info explains about the fuel stabilizers but seems to focus primarily on not letting the fuel sit around and keeping water/condensation to an absolute minimum during storage. The separate 6 gallon temporary tank is a crisp way to provide clean fuel and see if the problem persists. Run a clear fuel hose when you do this and make sure there are no air bubbles in the fuel being delivered. I once had an issue with my twin 200 optis and ran two separate 6 gallon tanks to debug, bypassed even the fuel bulbs. Ran fine as the initial diaphragm pump pulled enough vacuum.<br /><br />As to the battery, as long as the batteries are being maintained while at idle (@ 14 volts) this should not drive the engine to star acting weird all of the sudden. However, I caught hell wen a rep was on my boat as my dealer skimped too and put in a smaller than recommended battery. Yours is way under and odd as it seems, it is a variable you changed. Beg, borrow or steal a properly sized battery just to prove to yourself its not a part of the problem. The tech in my case said the alternator has been found to drive almost random RF problems when used with batteries way under the appropriate size. I vote for the fuel issue, but would not discount your new battery as somehow being tied into this. If the separate 6 gallon fuel tank of fresh gas does not bear fruit, nor the properly sized battery, you might want to hook up a fuel pressure gage to the schrader valve on the fuel rail and assure you have a constant pressure (@ 100 psi) when the problem is not present as well as present. I hooked in a remote sensor once with the actual gage wired up at the helm temporarily. Worked slick, allows the cowl to be placed back on while observing the hi output fuel pressure as you go about your boating. You can do the same for the high pressure air. You need to look for a constant delta of about 10 psi between them with the fuel being higher of the two.<br /><br />Good luck.
 
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