1987 Johnson 110 - Bogging down @ mid throttle

[Boss Hawg]

Had fuel delivery problems but fixed all that & bulb is now staying firm---Starts fines, idles fine & runs fine up to around 10mph (will do 30 when running right on my pontoon) but then bogs down? I can throttle down before it dies & it'll idle fine & go again at slow speed-if it dies it'll start right back up.

Compression is good & equal on all 4 cyl-
Cleaned carbs
New fuel pump
New tank
New bulb & fuel line
------
Coil failing under load maybe??
Don't know how to check that & can't think of anything else to do :blue:

 

[Daviet]

Re: 1987 Johnson 110 - Bogging down @ mid throttle

Couple of thoughts.
You can use a inductive timing light to check spark on the plug wires when the problem happens.
Sounds like you might have a fuel delivery problem.
If you have someone constantly pump the primer bulb will it run properly?
When you cleaned the carbs did you remove and clean all of the orifices in the carbs?

 

[Boss Hawg]

Re: 1987 Johnson 110 - Bogging down @ mid throttle

Couple of thoughts.
You can use a inductive timing light to check spark on the plug wires when the problem happens.
Sounds like you might have a fuel delivery problem.
If you have someone constantly pump the primer bulb will it run properly?
When you cleaned the carbs did you remove and clean all of the orifices in the carbs?

Bulb is still firm when it happens- before I put new tank & bulb/line on the bulb was collaspsed--thought it was fixed till I took it out yesterday-
Yes on carbs- Cleaned them a 2nd time to be sure-

 

[emdsapmgr]

Re: 1987 Johnson 110 - Bogging down @ mid throttle

Back to the question DaveT asked: if you constantly prime the fuel hose bulb, will the engine run ok at WOT? If you stop priming the bulb, does it quit running at WOT? If so, it's a fuel issue. Maybe a weak fuel pump.

 

[Boss Hawg]

Re: 1987 Johnson 110 - Bogging down @ mid throttle

Back to the question DaveT asked: if you constantly prime the fuel hose bulb, will the engine run ok at WOT? If you stop priming the bulb, does it quit running at WOT? If so, it's a fuel issue. Maybe a weak fuel pump.

No to both--
When it starts to bog down now the bulb is still firm & pumping it has no effect-
New fuel pump installed when problem first started-

 

[Daviet]

Re: 1987 Johnson 110 - Bogging down @ mid throttle

When you cleaned the carbs did you remove the high speed orifices and make sure they were not plugged or restricted?

 

[Boss Hawg]

Re: 1987 Johnson 110 - Bogging down @ mid throttle

When you cleaned the carbs did you remove the high speed orifices and make sure they were not plugged or restricted?

Yes sir-

 

[Daviet]

Re: 1987 Johnson 110 - Bogging down @ mid throttle

Well, there are a couple of ways to determine if you have a fuel or ignition problem.
You can remove the air box cover from the front of the carbs and try spraying fuel from a spray bottle directly into the carbs and see if it makes a difference.
You can use an inductive timing light to check each plug wire to see if you are dropping spark to any cylinders.
At least these checks might help you determine if you are fighting a fuel or ignition problem.

 

[Boss Hawg]

Re: 1987 Johnson 110 - Bogging down @ mid throttle

Well, there are a couple of ways to determine if you have a fuel or ignition problem.
You can remove the air box cover from the front of the carbs and try spraying fuel from a spray bottle directly into the carbs and see if it makes a difference.
You can use an inductive timing light to check each plug wire to see if you are dropping spark to any cylinders.
At least these checks might help you determine if you are fighting a fuel or ignition problem.

Thanks!

 

[slzpe]

Re: 1987 Johnson 110 - Bogging down @ mid throttle - I have same engine, same problem

Re: 1987 Johnson 110 - Bogging down @ mid throttle - I have same engine, same problem

I have same engine and same problem. Drive me nuts also. Plan to work on tomorrow. Did you solve your problem? I too have rebuilt the carbs and checked the fuel delivery.

Had fuel delivery problems but fixed all that & bulb is now staying firm---Starts fines, idles fine & runs fine up to around 10mph (will do 30 when running right on my pontoon) but then bogs down? I can throttle down before it dies & it'll idle fine & go again at slow speed-if it dies it'll start right back up.

Compression is good & equal on all 4 cyl-
Cleaned carbs
New fuel pump
New tank
New bulb & fuel line
------
Coil failing under load maybe??
Don't know how to check that & can't think of anything else to do :blue:

 

[Jetfixr]

Re: 1987 Johnson 110 - Bogging down @ mid throttle

So what fixed your engines guys?

 

[Bwil]

Did you ever fix the issue? I have same prob. These discussions keep dead ending without the resolution.

 

[GA_Boater]

Did you ever fix the issue? I have same prob. These discussions keep dead ending without the resolution.

For the 2nd time - Have you started a thread. Old and closed.