Losing RPMs on Merc 4 stroke 25 hP

[tblack111]

I have a 2007 4 stroke 25hp Mercury that had been running 5500 RPM. Earliar this week on the lake, after a fill up and 2 oz. of stabill, I dropped to 5000 Rpm.... Hit some turbulant water and it bounced back to 5500. Went out today and could only get 4200 to 4800 RPM...which of course slows my speed. Engine runs smooth... I just lost my RPMs. Plugs were changed in January and still look good. Funny it happened after a fill up and stabill treatment. Any idea of wat may cause the rpm loss? Runs smooth as ever, just not the power I have been ecustomed too for the past year.'

Thanks

 

[info404]

Re: Losing RPMs on Merc 4 stroke 25 hP

i read your problem, but really can't help. i'm only writeing because i just switched to the marine stabil and now i'm haveing the same problem. my boat feels like its running on one piston instead of 2. just wondering if its related in some way...good luck...04

 

[tblack111]

Re: Losing RPMs on Merc 4 stroke 25 hP

Funny thing, my first thought was the Stabil

 

[tblack111]

Re: Losing RPMs on Merc 4 stroke 25 hP

I talked with a guy at Mercury...he thinks I have a bad coil. Yet a local repairman say go ahead and change the plugs although I changed them in December and they look ok. I told him it did not skip and was running smooh...just lost rpms and he insisted on trying the plugs, for a fouled plug does not neccesarily mean a skip. I still dont understand that statement.

 

[sxmerc]

Re: Losing RPMs on Merc 4 stroke 25 hP

Don't think it's the Stabil that is your problem, or the plugs. I'm thinking you got something in your carb. The small four strokes are SUPER finicky about ANY contaminates at all. The jets and orafices in these motors are tiny. My two cents.

 

[info404]

Re: Losing RPMs on Merc 4 stroke 25 hP

after re evaluating my problem, its not from the stable..sorry. my secondary choke wasn't opening due to wear. just bad timeing i guess from when i first put the stabil in.

 

[sxmerc]

Re: Losing RPMs on Merc 4 stroke 25 hP

after re evaluating my problem, its not from the stable..sorry. my secondary choke wasn't opening due to wear. just bad timeing i guess from when i first put the stabil in.

Secondary what?????

 

[tblack111]

Re: Losing RPMs on Merc 4 stroke 25 hP

Tryed changing out my gas....got on the water, up to about 5200 rpm and zilch. She locked down. No smoke, no skip, no bells, whisltles or signs of distress. Would ot turn over, could'nt even pull the pull chord.....MAJOR PROBLEM