johnsongt150

[wayne smelser]

I have got a 1991 johnson gt150. Here lately I have been having trouble getting it to start. When this occurs I am not getting any fire at the plugs. I have replaced the power pak but it hasn't helped. Once it fires it runs and starts fine the rest of the day. I tthought it was from my onboard charger. It should not have nothing to do with the firing though, right? Any help would be greatly appreciated!!!!!! I have already sunk about $ 800 , and would really like to get this fixed!!!! Thanks

 

[petryshyn]

Re: johnsongt150

I would be suspicious of the shut down ignition wire. If I'm not mistaken, it gets grounded by the ignition switch when you shut down. If this wire is grounded somewhere, or someone connected an accessory to it, it surely wouldn't start. If this engine has two power packs and your not getting spark to ANY plug, this would be my suspicion. Also make sure the power packs are getting a good ground. I hope you looked at the emergency shut off switch?

 

[12Footer]

Re: johnsongt150

Schematic is right, and don't rule-out a defective emergency switch (this happened to my Bayliner, and I still haven't hooked it back up).

 

[clanton]

Re: johnsongt150

Did you replace the sensor with the new pack? Model number, 60 degree or 90 degree engine?

 

[wayne smelser]

Re: johnsongt150

I did ground the power pak straight to the block where the pack bolts on. I also tried taking the wire out of the plug (blabk with yellow stripe), supposedly the kill switch, this did not help either. Are you talking about the ac tual key switch? if so how do I check to see if grounding or bad? So what explains it starting fine after I finally get it started? The funny thing is , to get it started all I do is just keep trying!!!!<br /><br />Thanks

 

[petryshyn]

Re: johnsongt150

if that engine only has one power-pack, then the charge coil could also be the culpert. If you disconnected the black/yellow wire already, you've ruled out the emergency kill switch and the likelyhood of a ground in the harness.(providing you disconnected the wire close to the engine)

 

[wayne smelser]

Re: johnsongt150

I am not much on these motors. could you tell me where and how to check the charge coil? Thanks

 

[wayne smelser]

Re: johnsongt150

clanton ,what sensor are you talking about? This thing is literally driving me crazy!!!!!!!!!!!

 

[clanton]

Re: johnsongt150

How do you get it to start, when it starts? I am guessing that this is V6 90 degree crossflow engine, has Quickstart and S.l.O.W right?

 

[clanton]

Re: johnsongt150

How do you know that it is not fireing, when it wont start? Is it getting fuel?

 

[clanton]

Re: johnsongt150

How do you know that it is not fireing, when it wont start? Is it getting fuel?

 

[hondon]

Re: johnsongt150

Is your primer solenoid working properly,and are you using it as you should?

 

[petryshyn]

Re: johnsongt150

clanton...what is Quickstart and S.l.O.W ?

 

[wayne smelser]

Re: johnsongt150

all I do to get it started is just keep cranking. When it doesn't start on first crank it usually means something is wrong. So the last time out and it happened I jerked the plug out and my buddy cranked it over , NO FIRE. Yes the plugs are wet and you can see the gas and oil in the water where it is flooded. Clanton I can't answer your quickstart and S.l.O.W question because I dont know. But I have another question: can the three bank charger I have on this boat be causing some type of electronic failure? It may be coincidence but it seems to happen after I charge> I did put a disconnect on the main hot wire, should I try the rest?

 

[clanton]

Re: johnsongt150

Quick Start circuit in power pack and timer base switches from start sensors to run sensors. Engine starts on start sensor when cold and increase engine rpm to 1100. After warmup, switches to run sensors, rpms drop to idle. Warm engine starts on start sensors runs 5 seconds switches to run sensors, power for this circuit comes from power coil in stator, control is temp sensor in port cylinder head.<br />S.L.O.W. Circuit in power pack that reduces rpms to app 2500 when engine over heats, control is temp sensors in port and starboard cylinder head

 

[clanton]

Re: johnsongt150

Check all cylinders at once, if all cylinder are dead, do wiggle test on all engine wires from stator and timer base to pack. Check pins in amphenol connectors, some times the little pins will not make good contact. All wires and connectors good. Check for loose or broken magnets in flywheel. You need peak rading meter or meter with DVA function or adapter, troubleshoot ignition system. You have meter, check pack output to coils.

 

[clanton]

Re: johnsongt150

 

[wayne smelser]

Re: johnsongt150

from start of engine can you explain to me where the initial start begins, maybe if I have a better understanding of how this beast works I can beeter follow what you all are describing . I have performed the wiggle check and thought i had found the culprit, but next time it happened i tried the same wire and nothing. Is there anyway I can further check into this with an ohm meter? All plugs are dead !! went out today and had no problem starting, but tommorrow may be a different story. Could I pull flywheel and check underneath? I am by no means a mechanic but I do work as a machinist. If someone could give me fair directions I do believe I could tackle the task at hand. You guys are great!!!!! Thanks Again

 

[clanton]

Re: johnsongt150

Find connector from stator to power pack 6 wires, unplug connector, connect ohm meter to termial A and B should be 985 -+ 25 ohms, then check termial C. D. 985 +- 25 ohms. This is pack charge coil. Sensor should have 2 connectors with 4 wires, Red meter lead to termial D. black lead to A. B. C. readings will be 360 -+ 30 or 970-+ 100 ohms depending on the meter you have. This side ok do other side, for a total of 6 sensors. Then check between D. termial from each connector, should be 230-+30 ohms.

 

[petryshyn]

Re: johnsongt150

clanton, hows about a defective power coil in the stator. that would leave him sparkless as well wouldn't it?<br />

Good boating!