NC Angler Forums banner
1 - 19 of 19 Posts

·
Registered
Joined
·
7 Posts
Discussion Starter · #1 ·
I have a 89 Vision Bass Boat with a 1990 Johnson 90HP motor. I went out Saturday and when I left the boat ramp, boat was running fine. We stopped in the middle of the lake to check the map, but when we started again the boat was running very slow even though it was at full throttle. The boat would not even plane. Once I turned the motor off, I also had some difficulty starting it. I had to re-prime the bulb to get it started, it has never done that before. Got the boat home, hooked up a hose and muffs, and it started perfectly. Any ideas?
 

·
Registered
Joined
·
4,355 Posts
The only time that has happened to me (gunning it and going nowhere) was a couple times that I spun the prop hub on an I/O. When that happens the hub and spindle turn but the prop doesn't. Usually when it first happens you can make some headway but after a mile or two you're dead in the water.

Don't know if O/Bs work the same way. If they do you might want to check that out.
 
G

·
Yep. Sound like you have a spun prop. Not too costly. Depends now your prop is made. Might can just change out the inner hub. There is an inner hub made of rubber that seperates the inner spline collar from the rest of the prop. This works like a sheer pin and also helps dampen vibration comming off the prop.

I have had something wrap around my prop spindle before and cause it. I'd pull the prop off to make sure you don't have some twine or plastic wrapped around the lower unit output.

I have had that happen a time or two when got in a hurry and left my anchor in the water :)
 

·
Registered
Joined
·
7 Posts
Discussion Starter · #4 ·
Thanks for the idea. It's my first boat and was not sure where to start. I will check that out as soon as I can, unfortunately it may have to wait till this weekend. I will post back as soon as I do and let you guys know if that was it.
 

·
Registered
Joined
·
4,355 Posts
Another thing az ... if it is a spun prop the repair is sometimes more than trading your prop for another one that's been refurbished -- something a marina would be able to get/do. The bad part of the repair is that those hubs have to be pressed in. Unless you've got the right tools it is something I'd leave to the pros.
 

·
Registered
Joined
·
7 Posts
Discussion Starter · #6 ·
So would I need to take the prop off and take it to a repair shop? Does that have anything to do with the bulb needing reprimed and having problems starting? Would buying a new prop be better than having the old one fixed? What do I look for when I take the prop off to see if that is the problem? Sorry, like I said, I am new to this.
 

·
Registered
Joined
·
4,355 Posts
az - the prop is easy to remove. Just take it off and take it to a repair shop. They can tell you if it's broken. If so, they can either fix that prop or you can swap it for a refurbished one -- which, in my experience, will probably be in better shape than if you fixed you current prop.

If it's not the prop then you have to look at other issues which I'd be totally in the dark about.
 

·
Registered
Joined
·
76 Posts
It could be the primer bulb. They are inexpensive can be changed with a few tools. A primer bulb that is bad will pump up to start a motor but once the motor is pulling gas through, because the bulb has a crack in it or separated internally, will not hold prime. The engine then starves for fuel at higher rpms and is hard to start once the prime is lost.
 

·
Red X Angler
Joined
·
16,054 Posts
Primer bulb , fuel pump, or clogged filter. Might also be clogged hi-speed jets if it is carbed not injected.
If it is a spun hub you will get all the rpm without the movement. Did the motor rev up like normal but just not go fast?
 

·
Registered
Joined
·
7 Posts
Discussion Starter · #10 ·
Yes, it seemed to be running just as loud as normal, just no speed. It also seemed like when I backed off the throttle a little, the bow was not in the air as much and we seemed to go a little bit faster than it did at full throttle. I am taking the prop off tonight or tomorrow to take it to a shop. I am also going to take a look at the primer bulb and fuel line, just to be on the safe side. I will keep an update.
 

·
Red X Angler
Joined
·
16,054 Posts
If you are getting the rev and less motion its the prop for sure. Nothing else to "slip" in that gearcase.
 

·
Registered
Joined
·
505 Posts
I've been chasing basically the same problem on my 1990 60 Johnson (basically the 3 cylinder version of your engine) for months now. Been through the entire fuel and ignition system, and I'm now going through the fuel system for a second time with the aid of a retired OMC mechanic. Done just about every diagnostic test that is possible to do on these engines, and none have turned up anything, yet the boat loses power and will barely plane the boat off and won't get up to cruise RPMs, just as you describe. If the engine is running at high rpm and not moving, yeah the prop suggestions might be valid, but if it's losing power and the engine itself isn't getting up to speed, it's not the prop.

Believe me, I've heard and looked into all the 'armchair QB' suggestions :). In the end it's probably going to turn out to be something simple and stupid...

Sorry I don't have more words of encouragement, but good luck! My only advice is try to go about it in a methodical and logical manner, and don't just start replacing stuff. Get the factory service manual, good investment!
 

·
Registered
Joined
·
7 Posts
Discussion Starter · #14 ·
Hope we both can find the answer soon. I will keep posting, especially if I find out what is going on. Let me know if you find the answer too. How do I go about getting a factory service manual?
 

·
Registered
Joined
·
1,993 Posts
I believe these older motors are supposed to have a vent on gas cap--make sure it is open when running motor. Closed vent will cause problems similar to those outlined.
 

·
Registered
Joined
·
76 Posts
If the engine will rev up to operating RPM but you can't get on plane or reach speed then it sounds like the prop issue.

If it will not rev up then the fuel system seems to be the problem; bulb, separater, fuel line cracked, and or fuel filter.

Another cause is the timing system. This is controlled by the power pac. If it has a board problem, cracked so moisture has gotten to it, then the engine will act as you have described. Most times if this is the issue then the engine cannot take the added fuel at *** and sounds like it flooded but still runs not reaching operating rpm as the timing is off.
 

·
Registered
Joined
·
1 Posts
my problem was solved

hey guys I had to buy a trigger is what it is called for the motor it is quite expensive mine was 215.00 but we replaced everything inside the motor, the flywheel and cleaned the carbs and new everything and it turned out to be the trigger that kept the 3 cylinders from firing right. it made the cylinders fire right and bring back the speed.

hope that helps thanks


I've been chasing basically the same problem on my 1990 60 Johnson (basically the 3 cylinder version of your engine) for months now. Been through the entire fuel and ignition system, and I'm now going through the fuel system for a second time with the aid of a retired OMC mechanic. Done just about every diagnostic test that is possible to do on these engines, and none have turned up anything, yet the boat loses power and will barely plane the boat off and won't get up to cruise RPMs, just as you describe. If the engine is running at high rpm and not moving, yeah the prop suggestions might be valid, but if it's losing power and the engine itself isn't getting up to speed, it's not the prop.

Believe me, I've heard and looked into all the 'armchair QB' suggestions :). In the end it's probably going to turn out to be something simple and stupid...

Sorry I don't have more words of encouragement, but good luck! My only advice is try to go about it in a methodical and logical manner, and don't just start replacing stuff. Get the factory service manual, good investment!
 

·
Registered
Joined
·
1 Posts
I have a 89 Vision Bass Boat with a 1990 Johnson 90HP motor. I went out Saturday and when I left the boat ramp, boat was running fine. We stopped in the middle of the lake to check the map, but when we started again the boat was running very slow even though it was at full throttle. The boat would not even plane. Once I turned the motor off, I also had some difficulty starting it. I had to re-prime the bulb to get it started, it has never done that before. Got the boat home, hooked up a hose and muffs, and it started perfectly. Any ideas?
This just happened to me last week exactly. What was the fix?
 
1 - 19 of 19 Posts
Top