1986 Johnson 90hp...no spark....UPDATE #2

[roonie]

Hi all...i recently purchased a 1988 16.5 fibretech boat with a 1986 Johnson 90hp. The engine was overheated at one time then rebuilt professionally. I recorded 120psi all across the board..give or take 1 or 2lbs. The boat/engine was not run for 3 or 4 yrs after rebuild and now has no spark. The previous owner stated to me that it ran when last parked.

Ive checked all the grounds and cleaned up the batt. terminals and checked all fuses. Installed new battery.

Were these particular engines faulty in one area or another such as power packs etc.

Also the engine has the VRO system for which i would like an opinion on if i should disconnect or not. I thought i read some time ago that VRO systems were only bad for a couple years so i would like to know if 1986 was one of the bad years. I know i will probably get different opinions on whether or not to disable VRO.

Any help getting this boat on the water would be greatly appreciated.

 

[boobie]

IMHO I would disable the VRO and run 50:1. For no spark go to cdielectronics.com for trouble shooting procedures.

 

[roonie]

thank you boobie...i have gone to the cdi site and tried to follow but the trouble im finding is #1....someone has removed the numbered cover for all the connections next to the pack...and.....Some of my wires do not corrospond with the cdi wire colors.

Can you tell me which hoses on the VRO to cut and plug and which ones to leave. The way i understand it, the fuel pump is also part of the body of the VRO. Also some elec. wires to dissconect i assume? thanks

 

[emdsapmgr]

The CDI website is a good one. If you go to the top of the page in this Johnson section, you will see a section called "top secret files." Inside there are wiring diagrams in color-including one for your year engine.

 

[roonie]

thanks emdsapmgr....can someone tell me .......how do i know if this engine has "Quick Start" as mentioned in the cdi website

 

[racerone]

There is no " quick start " on any 86 models.----Step # 1 is to take the starter apart for inspection .----A slow cranking flywheel will not generate enuff voltage to get spark !

 

[emdsapmgr]

Quick start came out in the late 80's when OMC went to the single power pack. Yours is a dual pack engine.

 

[roonie]

Thank you so much you guys, so far. You guys have been great. Now....is there a way to find out if this engine is spinning faster than 250rpm for proper spark? I did notice some oil atop the starter housing before i blew everything off at the car wash the other day. Ive wondered that the fact that this engine had been overheated at one time may have burned up the lubrication inside and on the starter as well....am i correct in this assumtion or is the starter isolated and away enough to not be damaged by heat? I also know that my great running old 70hp evinrunde spun faster than this 90hp. So i guess the question is , should i try measure the rpm of this spinning engine before i start dissmantling the starter for inspection?

mmm....i just found this in the sticky section..."" If problem persists, remove starter and clean all surfaces where engine block and starter connect". Is this a fact that the starter needs to be grounded to the engine block in order to function properly?

I also wonder now, if the engine has not been run for 3yrs, could it be that the cyl. walls have build up of rust etc. causing a slow turnover?...or am i now overthinking this problem prematurely

 

[racerone]

No need to be afraid of taking that starter apart for inspection.-------Very easy to do.

 

[emdsapmgr]

On an engine that's been sitting, you may want to pre-lube it prior to starting. You can remove the spark plugs and squirt a small amount of oil, even 3-in-one oil into the cyls. Crank the engine to be sure it circulated in the cyl, then replace the plugs. You should test the starter prior to disassembling it. Jump start it with a set of automotive cables, connected to a known strong battery. If it cranks normal rpm's the starter is ok.

 

[roonie]

Thanks so much........emdsapmgr,...the starter is working/spinning i just worry the engine is not spinning fast enough to create spark


Again....is there a way to test the rpm this engine is spinning?

 

[roonie]

UPDATE...got her running in the driveway..new ignition switch ...had to disconnect the kill wire for now. Took her out tonight to a lake closeby..she is only running on two cyl. and now for some reason , the key wont shut the engine off. Got her back home and going to play more in the morning. Should a guy swap coils or swap power packs? Why would the key on a new ignition switch not shut the engine off?

I am thinking, the reason i have spark on two cyl only is because ive unhooked the kill wire to that side of the pack...being that i have two packs, the other packs kill wire still hooked to the other bank, has dissabled the spark on that bank. Anyone care to comment on my assumption? Anyone

 

[roonie]

Bump....Anyone ..please

 

[Bosunsmate]

Disable both kill wires and use the choke to kill it. Check your choke works.
Then see how many cylinders are firing.
Sounds like you are going to need to get a cheap digital multimeter and do some ohmn reading on the stator and timing base, you will need to somehow work out which wires which by tracing them back to source.
Post some pictures if you need further help with that

 

[Fed]

Reconnect the kill wire then find where the kill wire going to the controller is getting grounded. Probably through the ign swtch or the kill switch.

 

[emdsapmgr]

I've seen dual power pack engines the continue to run after the key is switched to off. One pack kept the engine running on spark to one head. Replaced the pack and it shut off normally. The identical packs can be swapped for testing purposes-one controls the spark to each head. If you swap the packs and the "no fire" situation moves to the other head, likely it's a bad pack.

 

[roonie]

Ok...ive been out working on the engine since 5am this morning...wheew. So....ive found that when i pull back the kill wire pin from the two packs (at the elec. plugs), that i then have spark. ...yet....when i test continuity direct to the kill wire up to the front, it has no breaks. What i did next was ...i found where someone removed/bypassed the kill switch in the controls..but they kept the ground going to all the other grounds on the controll housing. I removed the kill switch ground wire from the control housing and it seems to have solved not only the spark issue but the key now shuts off as well. The engine seems to run very well now....in the driveway. I have spark on all 4 cyl. See diagram from this site below. They are calling the kill switch, a lanyard switch. My question now is, ..should i be removing this ground to solve my problem or have I only found a quick fix,the wrong way?

http://forums.iboats.com/filedata/fetch?id=7137906

 

[Fed]

The kill switch (lanyard switch) closes to stop the engine by shorting the kill wire to ground.
By removing the ground you have disabled the kill switch.

 

[roonie]

The kill switch (lanyard switch) closes to stop the engine by shorting the kill wire to ground.
By removing the ground you have disabled the kill switch.

Fed....there never was a kill switch in place...someone has disabled it long ago.

 

[roonie]

Well i was out tonight with her at a nearby lake and this boat/engine runs awesome. I was able to get 44mph out of her and she starts and runs like a dream. If someone can tell me what is the matter with having this kill wire removed from the other grounds...im all ears ....other wise i will leave it detatched as it has solved all my previous mentioned problems