88 Johnson GT100, Starting Problem

cbcrawford

Seaman
Joined
Sep 30, 2004
Messages
74
Ok - I have a "new to me" Johnson GT100, 1988 4 cyllinder. The motor was rebuilt about 1 year ago, and due to the prior owner's financial (also why I was able to buy it!) situation, it is just now getting past the break-in period. <br /><br />It ran great for five trips, but now it doesn't want to start . . . The symptoms are such that I just replaced the starter battery, after one or two failed attempts to start, it seemed weak, the motor turned over slowly and laboriously. The new battery did not help (and yes, it did have a full charge).<br /><br />I have checked the fuel line up to the engine, all seems good and it spits when I push in the ball and squeeze the primer. The Injector is disconnected and I premix 50:1.<br /><br />I have a SELOC manual for the boat, but I wanted to ask the experts here what I should check next . . . oh yeah, the tank is full of fresh gas.<br /><br />CC
 
D

DJ

Guest
Re: 88 Johnson GT100, Starting Problem

Do this.<br /><br />1. Remove and clean THOROUGHLY the negative battery terminal, on the engine block.<br /><br />Use this starting procedure.<br /><br />1. Turn the key to ON-NOT start.<br /><br />2. Push the key in to prime. Hold the key in for a count of eight.<br /><br />3. Release key.<br /><br />4. Turn engine over, it should start.<br /><br />5. Push the key in (prime) as needed to keep it going.
 

cbcrawford

Seaman
Joined
Sep 30, 2004
Messages
74
Re: 88 Johnson GT100, Starting Problem

Thanks DJ - <br /><br />The ground seemed clean, maybe a 1/4 turn from as tight as could be, pulled, cleaned and reset.<br /><br />It Didn't start, but I didn't push it, I'd rather put it in the water than on the little cheap-o muffs. Should I hear something from the motor when I push the key in? a relay, a pump, anything? It seems quiet, but I also don't have the best hearing . . . should I have a partner push it in while I listen to make sure the primer is working?<br /><br />Thanks again!<br />CC
 
D

DJ

Guest
Re: 88 Johnson GT100, Starting Problem

SHO,<br /><br />You will hear nothing but "one click" as the solonoid does it's job.<br /><br />Make sure the red lever, on the solonoid is folded back toward the body of the solonoid.
 

cbcrawford

Seaman
Joined
Sep 30, 2004
Messages
74
Re: 88 Johnson GT100, Starting Problem

The red lever is facing the bulk of the solenoid. I had my daughter turn the key to the on position, then push the key in - There was no audible click at all from the solenoid.<br /><br />OK - have found this lovely item in my manual, will proceed to check out . . . stand by for more questions though! and thanks again for all the great help!!<br /><br />CC
 

cbcrawford

Seaman
Joined
Sep 30, 2004
Messages
74
Re: 88 Johnson GT100, Starting Problem

Update & Opinoins Wanted <br /><br />I put the meter on the solenoid between blue strip and ground, tested at 6.7 ohms, within the plus or minus 1.5 ohm of 5.5 ohms it should read. According to the manual this means the primer/choke system should be functional.<br /><br />Fact remained that there was no response to pushing in the key (audible).<br /><br />HOWEVER - when I turned the solenoid to manual, pumped the primer bulb twice, switched it back to run, I barely had to touch the key for the engine to roar to life . . . . I think the problem might just be the choke/solenoid.<br /><br />It seems to me that the solenoid, despite passing the ohmeter test, is indeed dead? Lemme know if anyone can think of something else to check, or how I should proceed - I'd hate to replace the unit without being certain . . .<br /><br />CC
 

sycamore

Seaman
Joined
Jul 12, 2004
Messages
60
Re: 88 Johnson GT100, Starting Problem

Pumping the bulb replaces the fuel pressure and flow supplied by the fuel pump to the solenoid/valve when you are cranking your engine. I hear the click from my solenoid, so it does sound like your solenoid is not opening the primer valve. If this turns out not to be bad, you might check the fuel pump. The only reason I say this is that even with the primer not working, you should eventually get the gas normally through the carbs and it would start.
 

cbcrawford

Seaman
Joined
Sep 30, 2004
Messages
74
Re: 88 Johnson GT100, Starting Problem

SOLVED!!! <br /><br />I decided to test beyond what the manual says for the solenoid (ony an OHM test there) - If it should react to the key being pressed, SOME kind of voltage had to come in via the purple striped wire and out the black ground. Put on a meter, and NOTHING THERE!<br /><br />Just for kicks I tested the ground, and no continuity. It seems that the solenoid is mounted on some sort of a ?fiber? ?plastic? air intake system, and there is no visible continuity from the ground on the solenoid to the motor ground. I would assume that there *should* somehow be one and that mine has likely ?worked itself loose? reently? <br /><br />The temporary (guess it could be permanent) fix was to run a jumper from the solenoid body ground to an engine ground, and sure enough, when I push in the key there is a VERY audible click as the primer/choke kicks in!<br /><br />Anyone have any final thoughts or ideas before I put this one to rest?
 

fireman57

Captain
Joined
Aug 24, 2004
Messages
3,811
Re: 88 Johnson GT100, Starting Problem

Sounds like you might want to clean and tighten all your connections. Glad you found the problem and don't have to buy a solenoid.
 

sycamore

Seaman
Joined
Jul 12, 2004
Messages
60
Re: 88 Johnson GT100, Starting Problem

The rebuilder before you got the motor most likely left the grounding wire off when they put it together.
 
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