1986 25 Hp Merc dies @ half throttle

[carholme]

Re: 1986 25 Hp Merc dies @ half throttle

Case;

Just for information, you say it is a 1986 but that s/n comes up as:

25 25 2-cyl 5942041 6185158 1982 USA

From here:

http://www.marinshopen.se/Motorer/O...Mercury2takt2cyl1825hp/tabid/483/Default.aspx

It is a model 1025220, parts listing here:

http://www.crowleymarine.com/mercury-outboard/676.cfm

Service Manual: 90-92235--1 for s/n 6416712 and Below.

Here is a service manual at a good price:

http://cgi.ebay.com/ebaymotors/Mercury-Outboards-Service-Manual-18-25-/350392734074

Gerry

 

[Maxz695]

Re: 1986 25 Hp Merc dies @ half throttle

do you have a single levr or double lever thottle. and also can your engine start in foward or reverse? seems alot of people on this site are having the same kind of trouble and no one has figured a good solution thats why where thoughing ideas out there. If the throttle has a neutral saftey switch it is located between Rev and Forward this switch may be shorting in the throttle. this would be about the point the engine cuts out under power somewhere mid throttle.Merc throttles work great when new but they work like crap when they become worn.Might be nothing be worth looking into. oops i already posted this info You might want to see if you can replace the reed valves if you can get to them there behind the carb pr should be. if there bad, th will spit gas out rather than take it in causing this putter you describe. on my 40 HP i would have to dismantle the engine to get to them I hope i never have to.I just hate to think that electrical is the problem due to the fact it idles great and is fine at WOT. i picture engine basics intake of fuel and the correct spark then think either missing spark or air gas intake is off other than this disturbance cause by outside influence key switch throttle bad bat connection etc. I don,t know if you can disconnect the wiring hanress from the boat and run with just the engine componants working to rule out outside interference.if the engine still runs like it was at this point it,s mehcnical issue fuel issue or electrical. I don,t know why a stator or trigger would work hi speed low speed but not in between doesn,t sound logical to me but I could be wrong