View Thread
Before Posting, Please Read Our Posting Guidelines Below.

1. Use the full 4 digit year for everything you are asking your question about. Example: 1962, 1988, 2000, 2011
2. Include the correct name of your Whaler model. Example: Montauk 17, Montauk 170, Outrage 26, Outrage 260
3. Include the length when necessary. Example: 16, 17, 18, 20, 22
4. Do not post your email address anywhere on this site as it is already in your user profile.

 Print Thread
1998 Johnson 50hp has mechanics stumped
dpdash
#1 Print Post
Posted on 06/03/11 - 12:47 PM
Member

Posts: 55
Comments: 0
Joined: 08/01/10

1998 Johnson 50hp 2 cylinder 20" shaft. I picked it up used a month ago. It started and ran fine on the stand. Good spark, compression, very clean and seemed like a bargain. Here is the sympton:

will idle but when put into gear under load(in the water) stalls out.
will not idle very well in gear but when going back to neutral, stalls.
occasionally when started and run at above idle, will run away up to about 2500rpms

What multiple mechanics have done so far:
cleaned/rebuilt carbs, twice, verified they are the right carbs for the engine
new wiring harness, was some chafing on original
new fuel pump
new plugs
checked/verified correct timing, linkage
replaced choke solenoid due to small crack/leak
power tuned/engine cleaned twice, filled cylinders and let it sit overnight. Alot of carbon came out the first time


Compression is 145/135, engine runs great at higher rpms, just dies at idle. Next step is to pull the head and see if the rings are sticking, not allowing enough suction to pull the fuel in at low rpms.

Any ideas??

 
John Fyke
#2 Print Post
Posted on 06/03/11 - 1:11 PM
User Avatar
Member
Personal Page

Posts: 1307
Comments: 0
Joined: 09/06/06

Have you check the fuel filter? Any fuel restrictions? Crimped fuel Line? Loose fuel line?


John Fyke
Re-Fit or Reef It
1979 15' Sport with Super Sport conversion and 70hp mercury.
 
CES
#3 Print Post
Posted on 06/03/11 - 1:20 PM
User Avatar
Member
Personal Page
Photo Albums
Project Albums

Posts: 2681
Comments: 7
Joined: 04/27/07

DP, it seems like you've just about covered all the bases on that problem. It seems to me like it has to be a fuel delivery problem......I'll defintely be waiting for finding out what the problem is.

Are your coils putting out what they should when under load??


Edited by CES on 06/03/11 - 2:10 PM
Cliff
1966 13' Sport with a 1993 40hp Yamaha 2 Smoker
 
dgoodhue
#4 Print Post
Posted on 06/03/11 - 2:52 PM
Member

Posts: 278
Comments: 0
Joined: 10/04/05

I don't know know about the 2 cylinder carbs but are they actually taking the time to set the idle. My 3 cylinder 60 up recently rebuilt carbs but they idled horribly and loaded up. The idle screws werent adjusted properly.


Dave
 
whalerman
#5 Print Post
Posted on 06/04/11 - 6:20 AM
Member

Posts: 540
Comments: 5
Joined: 06/26/07

Are the carbs syncronised and float settings verified to be correct? Fuel connector on hose or engine, o-rings in good order?


Edited by whalerman on 06/04/11 - 6:21 AM
THOM : 1999 Outrage 18, 2012 E-TEC 150, 2012 EZ Loader trailer
 
dpdash
#6 Print Post
Posted on 06/04/11 - 3:22 PM
Member

Posts: 55
Comments: 0
Joined: 08/01/10

brand new fuel tank, lines and fuel filter. Carbs have been gone over 3 times, all verified that they are set properly by multiple mechanics( 3 at the same shop). It has become a personal issue with all 3, they are taking this as a challenge. We'll see what happens on Monday

 
Turpin
#7 Print Post
Posted on 06/04/11 - 3:48 PM
User Avatar
Member
Personal Page
Project Albums

Posts: 434
Comments: 20
Joined: 07/04/08

Make sure freeze plugs in carb are not leaking air.



1963 13' Sport 50hp Evinrude
Maintaining a level of sanity that is socially acceptable
 
whalerman
#8 Print Post
Posted on 06/04/11 - 5:11 PM
Member

Posts: 540
Comments: 5
Joined: 06/26/07

Well if they are good hounds then they will find it. Sounds as if the engine is running too lean as it sudenly takes off to 2500


THOM : 1999 Outrage 18, 2012 E-TEC 150, 2012 EZ Loader trailer
 
Gamalot
#9 Print Post
Posted on 06/04/11 - 6:46 PM
Member
Personal Page

Posts: 1086
Comments: 3
Joined: 06/21/10

What you are going through is one of my worse fears. Chasing phantom ghost issues is probably the most expensive issues we boaters have to go through.

I just sold my 1991 Honda Accord wagon and no one could find the idle issue I was having. I spent well over $600 trying to get it running as it always had but no mechanic could fix it. The guy who bought the car came by 3 days later and it was idling perfect. It cost him $12 and he replaced the vacuum lines and solved the issue.

Some times these problems are so simple we overlook the obvious and replace all sorts of expensive valves and other parts only to find a two dollar part was all it needed. Mechanics have it in their nature or from their employer to always start with the most expensive option and move on from there. Do the simple stuff first before you employ the costly mechanics and shops! Fuel lines, filters, vacuum lines and what nots just to be sure you actually do have a bad issue requiring further research.

Try a fuel tank you know is working right from a friends boat. If you have not yet replaced the fuel lines from tank all the way up to the carbs then do that too. It sounds to me like you have an air or vacuum leak somewhere.

 
Ice Cop
#10 Print Post
Posted on 06/04/11 - 9:25 PM
Member
Personal Page

Posts: 85
Comments: 1
Joined: 08/24/09

TRY HAVING THE FUEL SYSTEM INCLUDING THE NEW COMPONENTS PRESSURE TESTED UNDER BOTH POSITIVE PRESSURE AND UNDER A VACUME,


1962 Custom
1989 120hp Evinrude looper
 
surfncnow
#11 Print Post
Posted on 06/05/11 - 5:51 AM
Member
Personal Page

Posts: 67
Comments: 0
Joined: 05/07/09

Not sure if this will help. But I purchased a new EPA compliant 7.5 Gal Moeller gas tank. I noticed the vent on the gas tank not allowing enough air in the tank. The engine would idle fine until you gave it throttle. It would stall around 2500 RPMs. I removed the vent screw from the gas tank and the motor run like a champ.

I'm gonna call Moeller on Monday and see if it's user error or if I have a defective gas cap with vent.

 
whalerman
#12 Print Post
Posted on 06/05/11 - 7:32 AM
Member

Posts: 540
Comments: 5
Joined: 06/26/07

Another thing to look into is to remove the carbs again, sorry, and remove the intake and reed box and examine the reeds very carefully for broken/cracked reeds as well as the gasket surface to the crankcase.


THOM : 1999 Outrage 18, 2012 E-TEC 150, 2012 EZ Loader trailer
 
dpdash
#13 Print Post
Posted on 06/07/11 - 11:28 AM
Member

Posts: 55
Comments: 0
Joined: 08/01/10

bottom cylinder is scored. I might have a deal on a powerhead, if not, I will probably fix it as the rest of the motor is looking pretty good right now

 
seahorse
#14 Print Post
Posted on 06/08/11 - 6:48 AM
Member

Posts: 103
Comments: 0
Joined: 05/21/06

dpdash wrote:
bottom cylinder is scored.


Did they find the scored cylinder, even though the compression was good, by using the leak-down tester like I mentioned to you on another boating forum?


http://www.thehulltruth.com/boating-f...umped.html

refer to post #5


Edited by seahorse on 06/08/11 - 11:47 AM
 
dpdash
#15 Print Post
Posted on 06/08/11 - 1:41 PM
Member

Posts: 55
Comments: 0
Joined: 08/01/10

no, pulled the head

 
CES
#16 Print Post
Posted on 06/08/11 - 4:35 PM
User Avatar
Member
Personal Page
Photo Albums
Project Albums

Posts: 2681
Comments: 7
Joined: 04/27/07

Do you have any leads on a new powerhead??

If you do a search on this sitefor Northland Performance, you'll come across a place I used for my motor. They get their parts mainly from the cold freshwater areas of the northern US and Canada. If I can find the post, I'll link it here.


Cliff
1966 13' Sport with a 1993 40hp Yamaha 2 Smoker
 
seahorse
#17 Print Post
Posted on 06/08/11 - 11:03 PM
Member

Posts: 103
Comments: 0
Joined: 05/21/06

Was the motor either run without a thermostat or was the thermostat either stuck open or corroded away or the pressure relief valve stuck open?

 
Jump to Forum:
Bookmark and Share
Today's Date & Time
November 25, 2024 - 2:50 AM
Visit our Sponsors
Wm. J. Mills and Co. - Boston Whaler Canvas


Specialty Marine - Parts and Accessories


Nauset Marine - Whaler Parts and Accessories


Carver Covers - The Best Covers Under The Sun



Click on logo to visit site
View all Sponsors Here
Users Online
Welcome
AuntiesMontauk
as the newest member

· Guests Online: 7
· Members Online: 0
· Total Members: 50,390
Login
Username

Password

Remember Me


Not a member yet?
Click here to register.

Forgotten your password?
Request a new one here.
Top 5 Models Posted
· Montauk 17 1,638
· Sport 13 1,366
· Outrage 18 556
· Nauset 16 402
· Sport 15 365

View all Models Here
Render time: 0.22 seconds Copyright WhalerCentral.com © 2003-2024 86,556,576 unique visits