merc 115 powerloss

[izu]

After much frustration took boat to local marina.they spent 7hrs making adjustments. Runs fine on land,sounds real strong with no load on it.put it in the water falls flat and dies at about 1200 rpm. Please advise

 

[Yepblaze]

Re: merc 115 powerloss

It could be an ignition, fuel, or mechanical related issue.

My first suggestion is take it back and complain.

Next is to find a more reputable, or experienced mechanic.

Third is to run standard diagnostics on it.
Ie: spark, compression, and fuel delivery testing.

Forth is to do more advanced model specific testing as described in service manual.

 

[Chris1956]

Re: merc 115 powerloss

Izu, Those motors will do that if the carb idle adjustments are set too lean. I hope the marina would know that, it is pretty standard for outboards. I would take it back. You can try and hit the choke when it is about to die. If it speeds up, it is very very likely the carb idle adjustment is too lean.

 

[ddennis]

Re: merc 115 powerloss

Also you said it "runs strong on land" If you are referring to revving the engine out of the water I would Strongly reccomend against that... no load on the engine will allow it to over rev and could run the chance of destroying it! slightly off idle wont hurt...but taking above 2000 or higher I wouldnt do....

 

[izu]

Re: merc 115 powerloss

thanks for your info and points of view.

 

[AMD Rules]

Re: merc 115 powerloss

izu,

Have you re-checked your spark again? I know you spent a lot of time trying to get it properly timed, and to get rid of that spark miss when idling. I'm curious...did you ever purchase a DVA meter to help diagnose the electronics?

I'd agree with Chris that the initial symptoms you describe are due to a lean condition, but I am also suspicious that the timing syncronization may not be set right either.

What did the shop do for you? "adjustments" ?

 

[izu]

Re: merc 115 powerloss

the shop mech said #2 &#5 where not firing we replaced 2 coils with two used ones he said wiring to coils from switch boxes where routed incorrectly.we replaced one PAC .He said he did dynamic timing and set up the carbs that were out of sync.he did not bay test boat did everything on rabbit ears cause marina was full of boats being winterized.he gave me back the boat after spraying blue paint on areas that it they were adjusted he could tell.he said the only screw that may need adjusting was idle speed.I took it to the ramp and sure enough with a load on it needed to increase idle speed so it would idle in forward gear without dying. Yet when I gave it throttle @1500 rpm and @5 miles per hr.was max speed any more throttle it cuts off.Starts up after disengaging with gear and running in fast throttle mode.hope this description makes sense.

 

[Yepblaze]

Re: merc 115 powerloss

It sounds like you are getting deeper into the original issue(s) not being resolved.

You need to tell your repair shop, or person that they have, that they have yet to resolve your original issue, and you expect it to be repaired.

Apparently their expertise, evaluation, and test procedures both before and after repairs stink.

If they continue to just fiddle with this and that, and mark it with paint to indicate such, it doesn't say much for them.

Assuming you have a detailed trail of incompetance. With work orders or repair orders and reciepts stating what you described as your reason for repair and thier applied services. You may have recourse legally for a refund to take elsewhere for the repair.

 

[CharlieB]

Re: merc 115 powerloss

Definitely need to check spark intensity, weak spark or fouled plugs will idle perfectly, untill you start to put any real load on it, then it just fails.

You need a real mechanic that will properly test the ignition system, AND the compression BEFORE attempting to adjust anything!!!!!!

Granted this is a very busy time of year for many shops winterizing LOTS of customers boats that are finished for the season, BUT............

a customer that still wants to use his boat is a customer that NEEDS SERVICE NOW. Period.

If you are NOT getting adequate service from your mechanic/shop, you do not have the right mechanic/shop, and need to take your business elsewhere.