Raw Gas coming from vents in foot of Opti 150

Wide Open II

Cadet
Joined
Jan 31, 2003
Messages
9
Now I'm really perplexed. While working on fixing a trim unit problem on my 1998 Optimax 150, I read in the manual that the fuse that protects the trim unit also protects the instruments. I checked the fuses on the side of the engine, but just to be sure, I turned the ignition switch to on to double check. The instruments worked. The cowling was off the port engine with the trim problem and when I turned the ignition switch, I could hear the fuel pump, (at least I think that's what I was hearing) run for a couple seconds. Just to completely double check, I turned the ignition switch on the starboard engine to verify instruments. The cowling was on that engine, and I didn't notice any noise from the pump. However, when I went back to the stern, I noticed a considerable amount of RAW GAS was coming from the vents and propeller exhaust on the "good" starboard engine. The port engine had no gas coming from it. Please tell me this is normal!!!! I mean about 1/2 cup of gas came out. I've washed it down, and no more now. I've never run these engines on muffs, only in the water, so I don't have a previous experience to validate this phenomenom. Cant find anything in the manual about it either. Help!!!<br /><br />Still trying to track down the trim problem too.<br /><br />Wide Open II
 

Reel Appeal

Chief Petty Officer
Joined
Aug 19, 2002
Messages
566
Re: Raw Gas coming from vents in foot of Opti 150

Wide Open,<br /> I do not know Mercury Optimax motors(only 80's) but my Johnson has a trim limit switch on the steering tube that had worked loose giving me similiar problems.Check around the tube where a steering cable would go through.Look for some type of 2 wire contact switch. :confused:
 

Mufasa

Petty Officer 2nd Class
Joined
Jan 9, 2003
Messages
109
Re: Raw Gas coming from vents in foot of Opti 150

Wide Open,<br /><br /> The fuse you are refering to protects the instraments and trim controls, the switch in the handle. The trim motor draws a lot of currant is controled by a pair of relays under the cowling. I have had to replace several trim motors on units newer than yours. First you need verify if you are getting power through the relays. Do you have a wiring diagram?<br /><br /> No you should not get a 1/2 cup of fuel out of the motor when trimed in. Take the cowling off and inspect it, remove the spark plugs and see if it is only one cylinder or several.
 

Wide Open II

Cadet
Joined
Jan 31, 2003
Messages
9
Re: Raw Gas coming from vents in foot of Opti 150

Yep, I went through the trouble shooting section in the Clymers manual regarding trim/tilt. Had 12.85 volts in all the right places. The relays "click" indicating they are passing the current, plus I verified with a VOM at the terminals. So my next thing is, unfortunately, probably gotta be taking the trim motor off and inspecting it for seizure.
 

KIWI MERCMAN

Seaman
Joined
Feb 1, 2003
Messages
58
Re: Raw Gas coming from vents in foot of Opti 150

Wide Open<br />You should not be getting ANY fuel from the vents or prop on an Opti. The opti is a direct injected Motor so for raw fuel to get down to your propellor something is wrong. VST tank may be leaking from vent but on this model the vent goes through the line to air intake via a filter. So check the filter for signs of fuel, its on the port side by the alternator. Or you may have a direct injector that has a problem and is leaking fuel direct into the upper cyl ( any one of the 6)and it is running out the exhaust ports into the leg. My guess is the later.I would not use until you get checked out as they can make a very large bang with a heap of raw fuel down there.<br />Safe Boating
 

Wide Open II

Cadet
Joined
Jan 31, 2003
Messages
9
Re: Raw Gas coming from vents in foot of Opti 150

Thanks to all. I finally made the decision to take it to the mechanic. Raw gas is not something I want to be dealing with. He seems to think, at first glance, that it might be a faulty injector. We'll see and hope for the best.<br /><br />Wide Open II
 
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