Johnson Powershift2 135 No Spark

[POSPirate]

I made the classic mistake of buying another boat without hearing it run(I know). it has a johnson powershift2 135 outboard. It could possibly be a 115 hp. the cover says 115 but the guy told me 135 and gave me the original badges. anyway, he told me it had spark and wasnt getting fuel. I hooked up the battery and although the starter seemed quirky at first it did end up crankin over pretty smooth and strong. now i did touch the cables to the battery backwards at first incase this is pertinent (recently saw an 04 civic with burnt out ecm due to backwards jumpstart). this was only for the quickest moment. it has no spark on any cylinder. the plugs were wet, either from me spraying intake cleaner(instead of ether) or from gas. the key switch is dangling loose but seems to work. im a fairly experienced automechanic and have worked on 2 strokes before. i have no manual at the moment. the guy gave me spare used coils with the boat making me think he may have replaced them. but whatever is preventin spark is common to all cylinders. what is this i hear about a kill switch circuit? i think i know where the neutral start switch is on the motor but i assume that would prevent cranking. i havent yet tried to start it in gear but ive been workin on it alone. and what of the powerpack? do they burn out easily(battery cables reversed momentarily)? i have no problem fixing the engine for a few hundred in parts but i dont want to just throw parts at it. maybe this guy took me for a chump or maybe it did have spark and wasnt getting fuel and i killed the ignition accidentally. a no fuel issue is simple for me to fix or get around. im not as confident on electrical but i should be able to fix this old engine (i do work and modern computerized(pos) cars. i just have little knowledge/experience about them. what do i check first? any other info or websites would be appreciated.

 

[ezeke]

Re: Johnson Powershift2 135 No Spark

The powerpack is shorted to ground by a black and yellow wire running from the ignition switch when the key is turned to off. If the problem is ignition related, disconnecting the large red plug at the engine and jumping the starter will get spark.

You have almost certainly burned your rectifier when you reversed your battery cables, so the best choice would be to disconnect it at the terminal block so that battery voltage does not get to the ignition system and ruin it.

Your engine needs 300RPM to fire the ignition. It requires a fully charged powerful battery.

The engine is lubricated only by the oil that you mixed with your gasoline at 50:1, so using starter fluids of any kind other than a spray bottle of pre-mixed gas is ill-advised.

 

[POSPirate]

Re: Johnson Powershift2 135 No Spark

i disconnected the multi wire red plug at the engine and jumped the solenoid. it still did not seem to have spark to me. i check spark stickin a screwdriver into the wire and holding it close to the spark plug. these are flat electrode spark plugs. are the sparks on these motors strong enough to jump a gap like this. i know my battery is good and strong. should i be checkin spark differently? i have more proper tools for this at work. is there something else to check or did i possibly not hook up another wire to power? the reg/rect is that little silver cylinder shaped thing with two wires going to it, right?

 

[POSPirate]

Re: Johnson Powershift2 135 No Spark

Next to the reg/rect(i think) i found what looked to be a fusible link. On closer inspection i found a blown 20A fuse in this large red wire. Im going to replace this fuse and see what happens. Whats this fuse for anyway?

 

[ezeke]

Re: Johnson Powershift2 135 No Spark

The fuse is in line with the positive power feed to the ignition switch.

The starter is the only thing beside the choke solenoid that uses the battery. The ignition is self contained and can be rope started (if you are strong enough).

You have to test for spark with all plugs out to be certain. That way there will be no load on the engine.

Rig a tester with some large nails and a board. You will get a 7/16 sharp blue spark at 300RPM. This CDI unit will give you an idea of what a commercial tester is like.

 

[F_R]

Re: Johnson Powershift2 135 No Spark

It's already been pretty well covered.
1. The rectifier is shot from reverse polarity. But that isn't preventing spark
2. It has to crank at 300rpm to have spark. Try it with the plug out (cranks faster with no compression load) If it fires with plugs out but not in, either it is cranking too slow or the ignition charge coils are shot in the stator. (Possibly the sensor, but sort of unlikely)
3. It should throw a 7/16" spark. You will know if it is working!!
4. The fuse is the power supply to the ignition switch. But has nothing to do with having spark because the ignition does not run off the battery.
5. The black/yellow wire between the power pack and key switch is the kill circuit. Disconnect it while troubleshooting to eliminate any possibility that it might be the problem.

Lesse, what did I miss?

 

[ezeke]

Re: Johnson Powershift2 135 No Spark

BTW, You can also test spark with KDT2756 tester for short money. You still should remove all the plugs for best results though. http://www.tooldesk.com/products/productDetail.aspx+id+2133

 

[POSPirate]

Re: Johnson Powershift2 135 No Spark

alright, i have confirmed spark on atleast one cylinder. Im not sure if I was expecting more or wasnt grounding the plugs well enough but not only did i see spark jump on one plug but i managed to give myself a bit of a jumpstart. Now i know i soaked the plugs and cylinders, theyre all wet. so i started messing with the fuel delivery which i was steered towards by the previous owner. in removing the fuel pump, i noticed that the large black middle plastic spacer component of the pump had large cracks emanating from the center. I was warned that these break easily. its already broke. next, the spring for the main plunger was installed on the wrong side of this spacer. I figured this out because of the nut imprint on the actual diaphragm and the fact that in putting it together the way i had disassembled it didnt make sense to me. so i have the main plunger basically working right. i can blow into the plastic nozzle one way and nut suck thru it. now the little plunger is seized in its guide so its not doing much. i have the replacement parts and will fix it at work this week. my question now is this, i cannot flow either direction through the brass nozzle of the pump. the line coming off this nozzle was also dry and empty. what is this line for? whats the smaller plunger for? are the cracks and gap in the plastic spacer around its center nut a major deal? i am hopeful that with a rebuilt pump, ill be on the river this next weekend

 

[ezeke]

Re: Johnson Powershift2 135 No Spark

There is a thread on fuel pumps at the top of this forum that has been in the works for a few weeks, It may help with the fuel pump issues. http://forums.iboats.com/showthread.php?t=240864

The lift pumps either get their pulse through the back of the pump, like the lead one in the thread, or through a third hose in pumps like yours.

 

[POSPirate]

Re: Johnson Powershift2 135 No Spark

well after confirming spark it was a short decisive battle. took the fuel pump apart, played with it for a while and figured out how it was actually supposed to be put together. i freed up the little plunger. even with the cracked manifold plastic spacer and one gasket i scraped off the back, i put it together and primed it with some good gas. i cleaned and dried all the plugs and had let the motor air out today with the plugs out. pulled the choke and cranked, fired right up. i was ecstatic, i got a good boat outta the deal. thanks for all the advice. now if that one spot of wood wasnt so soft....lol jk

 

[sheve12]

Re: Johnson Powershift2 135 No Spark

I seem to be having the same problem, I have a 1975 135hp I hadn't run for a while when i got it but after a half hour in the water it stopped stalling and was running fine. The rectifier soon began to smoke and seemed to burn out. The boat still ran and started up then a few days later everytime i tried to start it and the electric choke kicked in it would blow the 20a fuse. after blwing about 8 fuses trying to figure it out i ran out of fuses and had 1, 25 amp fuse so i put it in and it worked motor started right up and ran fine for a week. One time shortly after the autochocke started to smoke and seems to be burnt out. I figured out the manual choke and continued using it but when going full board it would randomly shut done then start right back up until it finally would start back up. I checked the rectifier and wires crumbled right out of it and it has no spark on any plugs..... What Did I DO?!!!

 

[ezeke]

Re: Johnson Powershift2 135 No Spark

A rectifier is a system of diodes that converts the alternating current to direct current for charging the battery. Diodes allow voltage to run in only one direction. When voltage to a diode is reversed by any means, the diode is destroyed and generates heat in the process.

If the heat is sufficient to melt the potting material, it is possible for the wiring within the rectifier to fuse, permitting the battery voltage to reach the ignition components and damage them.

Whenever a problem with a rectifier is suspected, it is best to remove it until the rectifier is tested, or until a replacement can be found. The rectifier is not necessary for operating your motor, but the battery will need charging and your tachometer will not work.

If battery voltage has reached the stator, you may be able to see damage to the green potting material by looking up under the flywheel. If it is damaged, you may need to replace it.

Your motor has a temperature sensor on top of the engine next to the lifting eye. The sensor is part of the choke system and provides the ground to activate the choke when the engine temperature is below 96 degrees +/-.

The choke solenoid is also manually activated by the expedient of a toggle switch located on the remote control.

Because of many problems with the automatic choke part of the system, most of them were disabled by service departments subject to OMC Service Bulletin # 1335, February 1974. The chokes' solenoids were then rewired to be used strictly through the toggle switch.

 

[sheve12]

Re: Johnson Powershift2 135 No Spark

Thanks for the response. I ordered a new rectifier but I did notice that under the fly wheel there are 2 black plastic pieces that have a hardened black drip coming down from them almost like plastic melted unless its just the stuff used to install it. two of the coils also have a small crack in the top but they ran fine with the crack in them. The last thing that happened is after when i was running full board it would die out sometimes i could ease throttle and it wouldn't stal but i would have to let it idle. the last time it just died like it had before but never started back up. What else do you think I should replace.