Outboard Motor Repair Outboard Motor Repair  

Outboard Motors

Power Heads

Lower Units

Props

Repair Manuals

Controls, Steering

Trim/Tilt

Power Tilt/Trim

Parts

Outboard Motor Repair


Chrysler
Evinrude
Force
Honda
Johnson
Mariner
Mercury
Minn Kota
Nissan
OMC
Suzuki
Yamaha
2 Cycle Outboard Motors
2 Stroke Outboards
4 Cycle Outboards
4 Stroke Outboards
Aftermarket Outboard Parts
Boat Wont Plane
Bolts
Brackets
Carburetors
Cavitation
Choke
Coils
Compression
Condensors
Controls
Cooling
Cowling
Crankshafts
Cylinders
Diagrams
EFI
Electrical
Engine Cleaner
Engine Smoke
Exhaust
FICHT
Fins
Flywheel
Fouling
Fuel Pumps
Fuel Systems
Fuel Tanks
Gaskets
Gauges
Gear Cases
Generators
I/O
Idle
Ignition
Impellers
Inverters
Kill Switch
Leaks
Lower Units
Lubrication
Manuals
Oil
Oil Injection
Oil Mixture
Old Outboards
Outboard Engine Blocks
Outboard Inboard
Outboard Maintenance
Outboard Motor Prices
Outboard Propellers
Paint
Parts
Pistons
Power Loss
Power Packs
Powerheads
Primer Bulb
RPM
Repair Tools
Reverse
Running Lean
Running Rich
Runs Hot
Sea Drives
Sealants
Shafts
Shifter
Skegs
Spark Plugs
Specs
Spring Maintenance
Starter Motors
Starting Problems
Stators
Steering
Synthetic Oil
Tachometers
Tillers
Tilt Trim
Timing
Trim Tabs
Twin Outboards
V6
Voltmeter
Water Pumps
Winterization
Wiring
Year

84 50hp. mercury with no top end . HELP!!!!

trpm74655 I have a 1984 50hp. merc on a pontoon boat. The problem is I can only get about half speed under load. Have had the boat and motor since they were new . I put it in the shop twice in the last year and they cant find the problem. I have checked fuel system , carbs, compression and have spark on all four cylinders. Have been reading from this board and think it may be the high side windings on the stator. Checked impedance between red and red white and got 0 ohms ,full closed circut.
Would apperciate any help.
Thanks Rex P.
2001-08-20
DUTTON I had the same problem with my 50 merc,it would not reach WOT, it turned out to be the ignition box. Replaced it and it runs at 5500 rpm's Your box and or wires may be breaking down under load. Is the prop slipping? 2001-08-22
trpm74655 Thanks for the reply Dutton , I have checked the prop. BUT I made the mistake of taking the shops word that the fuel system and carbs had been fully checked. Took the {edited} thing apart my self and found bottom carb was way out of adjustment and throttle linkage between the carbs was split. It is fireing on all fours now .Going to put it in the water tomarrow and see how it runs now.
Thanks agian REX P.
2001-08-22
trpm74655 Well i put the piece of junk back in the water today and it is still bogging down after about 1/3 to 1/2 throttle. Only duz this under load . Any help would be welcome Rex P. 2001-08-23
corm pull off the top 2 plug wires to see if it is running on the bottom carb, or put some gas & oil in a squirt bottle and shoot some in the carbs to see if it picks up some rpms.
if so it is the fuel sys. Pumps maybe, try squeezing the primer bulb to see if it runs more RPMs. If you pull off one plug wire and get no change you could have a bad plug or switch box, the coils usually don't go bad on these motors.
2001-08-24
trpm74655 Thanks for the reply Corm. I pulled the plugs one at a time a couple of days ago and found the two for the bottom carb had no effect on the motor. Checked and found the throttle linkage between the top and bottom carb (which is plastic) was split. I replaced the broken linkage and now if any one of the four plugs is puled it effects the motor. I tried spraying fuel from a squirt bottle into each carb one at a time and neither increased the rpms. Tried pumping bulb and still no change . Running out of options. This may sound like a stupid question but are the throttle on top and bottom carbs susposed to be in alienment with each other ? Because when I replaced the linkage between the carbs I lined them up like I would on a set of carbs on a motorcycle. Any Ideas would be welcome.

Thanks: Rex P.

2001-08-24
corm Hi,
You set the carb butterflys right.
As for the bog problem I am at a loss.
Maybe the high speed stator is bad and not producing enough power to fire the plugs.
Causing it to not burn the fuel to reach top RPM.
corm
2001-08-25
kev_79 I would rebuild the carbs, if you already haven't. I had a prob very similar to yours and it turned out that their was a gasket between the bowl, and the passage where fuel from the main jet came out. It was smashed, and old, so when it started to switch over to the main jet for power, it would bog down. As for the first 1/4 throttle, you couldn't tell anything was wrong. I would try this first, since I think the gasket kits for the carbs are something like 4 bucks a piece. Just pray stator is good, becuase it can be a job changing (getting flywheel of sometimes a real *****), and to have freshly rebuilt carbs can't hurt you cause. Good Luck, tell us how it goes. 2001-08-25
trpm74655 Thanks for the replies Corm and Kev_79. I will check the carb gaskets and hope its not the stator! Anybody know the numbers for the ohms test for the stator? And you check between red and red/white for high side?
All and any help is very welcome!
( 1984 50 hp. 4 cyl. Mercurcy )
Thanks Rex P.
2001-08-25

If you would like to post your own question for the experts just click on
the Boating Forums tab at the top of the page or click here!

Disclaimer: iboats.com provides this content for the education and benefit of all boating enthusiasts.
We cannot, however, take responsibility for individual postings, nor can we verify the accuracy of any posting.
Please use any information provided from individuals with great care and read any applicable manuals or safety instructions.
Also, if you determine that a posting is inaccurate or offensive in any manner, please use the Contact Us email form found below.

If you would like to post your own question for the experts just click on the Boating Forums tab at the top of the page!


Outboard Motors

Power Heads

Lower Units

Props

Repair Manuals

Controls, Steering

Trim/Tilt

Power Tilt/Trim

Parts

Outboard Repairs | Boats | Outboard Motors | Boat Dealers
Boat Covers | Boat Propellers | Boat Repair | Marine Engines | Outboard Forum Directory
Terms of Use | Privacy Practices | Legal Notices

1-800-869-1686 (Toll Free)
001-801-571-0071 (International Calls)
Copyright © 1999-2009 iboats, inc. All rights reserved.