1987 50HP Johnson need some help

Monte1961

Lieutenant Junior Grade
Joined
May 8, 2011
Messages
1,180
Re: 1987 50HP Johnson need some help

I think what you maybe describing is whats called a lean sneeze! Welcome to iboats.
 

BonairII

Commander
Joined
Jun 7, 2011
Messages
2,727
Re: 1987 50HP Johnson need some help

What exactly is happening? Does it run better when you give it throttle? We need a bit more info to even begin to diagnose.

But to answer your question...No....a bad water pump will not cause your motor to sputter. If you're motor isn't pumping a good amount of water right now, don't even run your motor til you replace your impeller.
 

beto

Cadet
Joined
Aug 14, 2011
Messages
16
Re: 1987 50HP Johnson need some help

I bought and have had the boat in the water since April. I had some issues in the with the fuel system, but have since replace all the fuel system including removing the vro pump and modifieing a bracket for a regular fuel pump. It had been running great the last three or so months till last Sat. I was heading out full throttle and it just startd sputtering. I noticed it was not spitting the same amount of water that it usually did. So I figured it could be the pump. At full throttle it sputters a little but then gos and water seems to flow right. At low speeds pulling in to my slip or just crusing speed it sputters and water does not flow right. :confused:
 

BonairII

Commander
Joined
Jun 7, 2011
Messages
2,727
Re: 1987 50HP Johnson need some help

When is the last time you cleaned and serviced the carbs? Prob got some gunk.
 

beto

Cadet
Joined
Aug 14, 2011
Messages
16
Re: 1987 50HP Johnson need some help

I bought and have had the boat in the water since April. I had some issues in the with the fuel system, but have since replace all the fuel system including removing the vro pump and modifieing a bracket for a regular fuel pump. It had been running great the last three or so months till last Sat. I was heading out full throttle and it just startd sputtering. I noticed it was not spitting the same amount of water that it usually did. So I figured it could be the pump. At full throttle it sputters a little but then gos and water seems to flow right. At low speeds pulling in to my slip or just crusing speed it sputters and water does not flow right.



Edit Post Reply Reply With Quote
 

beto

Cadet
Joined
Aug 14, 2011
Messages
16
Re: 1987 50HP Johnson need some help

Carbs are clean. I removed and cleaned them yesterday. I kind of have them down, but in all honesty they didnt needed. Changed the plugs it has good spark.All my fuel lines seem fine I dont know?
 

beto

Cadet
Joined
Aug 14, 2011
Messages
16
Re: 1987 50HP Johnson need some help

Monte
Haven't done anything different with the fuel. 50 to 1 oil mix. Had been running great till now.
 

BonairII

Commander
Joined
Jun 7, 2011
Messages
2,727
Re: 1987 50HP Johnson need some help

Why are there 2 identical threads about the same prob? :confused:
 

beto

Cadet
Joined
Aug 14, 2011
Messages
16
Re: 1987 50HP Johnson need some help

Yes I have a tell tale. I am sure carbs and fuel system are clean. The spark is there too, pulled each wire off one by one while running and there was a nice ark. The only diffence I see is the water flow through the teall tale. Should I check compression? If I do what should it be at?
 

beto

Cadet
Joined
Aug 14, 2011
Messages
16
Re: 1987 50HP Johnson need some help

I posted one under the wrong forum and then under the right one. I guess they corrected it. Sorry my first forum.
 

BonairII

Commander
Joined
Jun 7, 2011
Messages
2,727
Re: 1987 50HP Johnson need some help

The spark is there too, pulled each wire off one by one while running and there was a nice ark.

Don't be so sure about the "nice arc" thing. I used that same method the last couple days with my 80hp and found out that my 'nice arc' wasn't hot enough to fire 2 of my cylinders. Ended up cleaning and resetting my points, and cleaning up electrical contacts and it solved my prob.
I'm not familiar with your motor, but all of that is food for thought.
 

beto

Cadet
Joined
Aug 14, 2011
Messages
16
Re: 1987 50HP Johnson need some help

Yeah you have a point. It should still be flowing water through the tell tale even if just ideling though right?
 

beto

Cadet
Joined
Aug 14, 2011
Messages
16
Re: 1987 50HP Johnson need some help

I dont even know if mine has points. What year is your motor?
 

beto

Cadet
Joined
Aug 14, 2011
Messages
16
Re: 1987 50HP Johnson need some help

Will do thanks. What is the most common problem with these engines? Electrically anyways
 

Borgey401

Petty Officer 2nd Class
Joined
Jun 11, 2011
Messages
155
Re: 1987 50HP Johnson need some help

Yeah you have a point. It should still be flowing water through the tell tale even if just ideling though right?

Yes water should still be coming out the telltale even while at idle. I would test the spark if I were in your position. Go purchase a spark tester, they're pretty cheap (around $10-$15) and you can get them at an auto parts store. Post back with the results and I'm sure some of the experts will help you along further. I would also check compression too while you're at it.
 
Top