Boatmad.com


Reply
 
Thread Tools Display Modes
 
Old 28-04-2016, 05:23 PM   #1
Registered User
 

Join Date: Oct 2013
Posts: 45
125hp 2-stroke Mercury 1998 skipping a beat

I winterise my engine each year but still start it up and warm up the engine every month.

I just dropped it in the sea for the first time since October, added fuel system cleaner to the correct ratio.

Motor runs fine, after an hour of running at 3000rpm I upped it following my old school of thought relating to an engine needed WOT to give it a good clean out every once in a while.

At 90% it runs with no problem. At 100% you get an initial boost but then the engine started to give in a bit and I could hear it wavering, dropping down and picking up in revs. Overall at 100% we were going 2-3mph slower than at 90% despite an initial surge.

Dropping back down to 90% and the symptoms disappear.

Any ideas? Could the fuel filter need a clean? Or could this be a bigger/other issue?
__________________

eshroom is offline   Reply With Quote
Old 28-04-2016, 05:43 PM   #2
Registered User
 
Hydrostream's Avatar
 
Country: Ireland
Location: Dublin
Occupation: Boatbuilder
Boat make: Hydrostream V-king, 650SS OCR ,Ring 21, Ring 18, Phantom 18.
Engines: 300Hp Mercury 2.4, 130 Yamaha, Bridgeport EFI, XR6, Merc 200.
Cruising area: Malahide, Dublin

Join Date: May 2004
Location: Dublin
Posts: 1,803
When it happens get someone to squeeze the priming bulb and see if it improves.
Or bump the choke momentarily..
__________________

__________________
www.powermarine.ie

[SIGPIC][/SIGPIC]
Hydrostream is offline   Reply With Quote
Old 28-04-2016, 06:34 PM   #3
Registered User
 
blackbeard's Avatar
 
Country: isle of wight
Location: on a rock
Interests: boats,boats and boats
Boat make: Cougar 21
Engines: Merc 2.5 promax 150
Cruising area: solent

Join Date: Oct 2007
Location: on a rock
Posts: 712
When was the fuel pump last rebuilt,if not for a couple of seasons i would get a service kit and try that
blackbeard is offline   Reply With Quote
Old 30-04-2016, 02:43 PM   #4
Registered User
 

Join Date: Oct 2013
Posts: 45
Cheers for the replies. I went out today and the problem didn't resurface (which makes me think it is the fuel filter - in which case do I simply replace it?). I've lost a little on the top end (5% or so), but no more choking. I tried the choke at speed and it seemed to cut power all together until I released the choke.

I haven't rebuilt anything in the past 2 years. Just a service each year which I do myself as per the manual. I do about 20-25 hours a year.
eshroom is offline   Reply With Quote
Old 30-04-2016, 04:26 PM   #5
Registered User
 
Location: IOW
Occupation: Marine and Electrical engineer

Join Date: Nov 2007
Location: IOW
Posts: 56
fuel only has a shelf of 6 months if not treated, after that it breaks down and can leave a gel behind which can block jets in the card etc. I would strip and ultra sonic clean them.
adykitcher is offline   Reply With Quote
Old 30-04-2016, 04:28 PM   #6
Registered User
 
Location: IOW
Occupation: Marine and Electrical engineer

Join Date: Nov 2007
Location: IOW
Posts: 56
this will stop if from happening

https://www.quicksilver-products.com...ems/additives/
adykitcher is offline   Reply With Quote
Old 30-04-2016, 09:18 PM   #7
oxo
Registered User
 
Country: england
Location: isle of wight
Occupation: stonemason when the water's too rough!
Interests: boats engines beer
Boat name: outlaw
Boat make: marshan 18/crusader 17
Engines: merc xr2/ merc115
Cruising area: solent/round island if i got enough fuel!

Join Date: Oct 2008
Location: isle of wight
Posts: 218
filter

swap out the water separating fuel filter first! I've rebuilt carbs time after time only to find out I've made that schoolboy error!
oxo is offline   Reply With Quote
Old 01-05-2016, 01:57 PM   #8
Registered User
 

Join Date: Oct 2013
Posts: 45
Great, thanks. I will do both of the above.

I've been servicing my engine with generic alternatives to the suggested quicksilver products since in Greece it is almost impossible to find quicksilver products at the moment. I've noticed the chemical make up of the various greases and oils are not the same as the quicksilver ones.

I'm going to start posting them over from the UK I think.
eshroom is offline   Reply With Quote
Old 01-05-2016, 04:42 PM   #9
Registered User
 
Location: IOW
Occupation: Marine and Electrical engineer

Join Date: Nov 2007
Location: IOW
Posts: 56
Quote:
Originally Posted by oxo View Post
swap out the water separating fuel filter first! I've rebuilt carbs time after time only to find out I've made that schoolboy error!
Yes school boy error would of not been changing the filter first. Always work from the fuel tank, fuel lines, Fuel filters, connections etc working your way to towards the engine until you get to the pump and carbs etc.

Costumers engines not so much (as the dont like paying for it) but on my own engines i strip and ultra sonic clean the carbs every years as if its an service item. Doesn't take long and its peace of mind knowing its been done!

We would be help to ship quicksilver stuff to you if u so wanted!

Hope this all helps.
adykitcher is offline   Reply With Quote
Old 08-07-2016, 07:21 PM   #10
Registered User
 

Join Date: Oct 2013
Posts: 45
Got all this done. You don't even want to know how I replaced the fuel filter (base had been bolted with non stainless bolts that had rusted right through).

I've clawed back 2 of my lost 5 mph on the top end. I'll do an ultra sonic clean before next season. Thanks for all the advice!
__________________

eshroom is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Powered by vBadvanced CMPS v3.2.3

All times are GMT +1. The time now is 09:52 PM.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
×