suspected timing issue on 74 15hp johnson *updated*

[someone11]

Im fixing up a motor for a relative of mine, its a 1974 johnson 15horse. It has sat in the barn for probably 15 years now. First thing I did before starting it was pull the carb and clean it out and checked for spark. Everything checked out fine so I hooked it up to muffs and started it up. Surprisingly it started up, idle was a little off but it purred nicely for sitting for so long, though it wasnt pumping water. So I ordered a new water pump and carb rebuild kit just for insurance. After replacing the water pump, the thermostat, and doing a carb rebuild im where im at now. Tried to start it up last night but no go. New plugs and very strong spark. It turned over once with a little starting fluid (yes I know starting fluid is bad to use, i only used a tiny bit to hopefully help pull new fuel through the lines), but after that nothing. With as strong of spark as its getting i dont know why it wouldnt fire on starting fluid? Im kinda lost on what to do next. I pulled the flywheel and the points are clean and set properly, I was told the points where changed before the motor sat. I know there is a mark on the cam that is supposed to line up with the roller at some point. I just dont know when or where thats supposed to be. When in neutral and I turn the tiller as open as it will go, the mark on the cam is to the left of the roller. (IE, when the tiller is as slow as it will go the mark is very far to the left of the roller). I dont think this is right from what ive read but im unsure. Any help would be greatly appreaciated.

 

[AlTn]

Re: suspected timing issue on 74 15hp johnson, help!

Re: suspected timing issue on 74 15hp johnson, help!

adjust it so the center of the roller is in line with the mark on the cam...at this point the throttle plate should have opened slightly...you make have to loosen the throttle control cam screws and pull it foward to achieve this...after adjustment and the motor in gear, the throttle plate should close completely at idle and be perfectly horizontal at wot < not over rotated >

 

[someone11]

Re: suspected timing issue on 74 15hp johnson, help!

Re: suspected timing issue on 74 15hp johnson, help!

So at just slightly open throttle the roller cam and mark should be lined up?

 

[AlTn]

Re: suspected timing issue on 74 15hp johnson, help!

Re: suspected timing issue on 74 15hp johnson, help!

yes..in neutral..as far as you can advance the throttle, line them up so the throttle plate is slightly open....it's possible to get the throttle plate to over rotate at wot in gear, so be sure to check this as well

 

[someone11]

Re: suspected timing issue on 74 15hp johnson, help!

Re: suspected timing issue on 74 15hp johnson, help!

Alright thanks. Could this cause it not to start?

 

[AlTn]

Re: suspected timing issue on 74 15hp johnson, help!

Re: suspected timing issue on 74 15hp johnson, help!

can make it much more difficult to start on older 9.9/15 hp.'s

 

[someone11]

Re: suspected timing issue on 74 15hp johnson, help!

Re: suspected timing issue on 74 15hp johnson, help!

can make it much more difficult to start on older 9.9/15 hp.'s

Would it completely prevent the motor from starting? Im just baffled as to why it wont start with good spark and starting fluid. Im hoping its not low compression. Thats the only thing I can think of.

 

[AlTn]

Re: suspected timing issue on 74 15hp johnson, help!

Re: suspected timing issue on 74 15hp johnson, help!

2 things come to mind...spark plug wires got switched < top to bottom....reverse them and see if that's it > or, you have a sheared flywheel key < doesn't take much misalignment between the flywheel and crank to cause a no start condition >

 

[Bob_VT]

Re: suspected timing issue on 74 15hp johnson, help!

Re: suspected timing issue on 74 15hp johnson, help!

Check this link for some information too http://www.leeroysramblings.com/OMC_info/OMCinfo.htm

 

[someone11]

Re: suspected timing issue on 74 15hp johnson, help!

Re: suspected timing issue on 74 15hp johnson, help!

2 things come to mind...spark plug wires got switched < top to bottom....reverse them and see if that's it > or, you have a sheared flywheel key < doesn't take much misalignment between the flywheel and crank to cause a no start condition >

Flywheel key is fine, I pulled the flywheel and checked everything out. And the top coil goes to the top cylinder and the bottom for the bottom cyl right? Thats how I have it im pretty sure. I cant work on the motor again until monday. Im grabbing my compression tester this weekend.

 

[AlTn]

Re: suspected timing issue on 74 15hp johnson, help!

Re: suspected timing issue on 74 15hp johnson, help!

on the link provided by Bob_VT..go to Johnson/Evinrude Magneto Ignition ( Numerous Models and Years )..~ 2/3's down the page, LeeRoy begins covering the ignition on your model year

 

[someone11]

Re: suspected timing issue on 74 15hp johnson, help!

Re: suspected timing issue on 74 15hp johnson, help!

on the link provided by Bob_VT..go to Johnson/Evinrude Magneto Ignition ( Numerous Models and Years )..~ 2/3's down the page, LeeRoy begins covering the ignition on your model year

Yeah ive skimmed over all the pages on leroy's ramblings. I know the timing is off on this motor. Hopefully fixing that will get it to start.

 

[OptsyEagle]

Re: suspected timing issue on 74 15hp johnson, help!

Re: suspected timing issue on 74 15hp johnson, help!

I know the timing is off on this motor. Hopefully fixing that will get it to start.

How do you know that? Timing is pretty much fixed by ensuring your point gaps are at 0.020", which I believe you did, and ensuring that the carb roller is aligned with the throttle cam, which I believe you did. I think you also confirmed that the spark plug boots and/or coil clips are all going to the right cylinder. That's your timing right there. You could put a multimeter on the points and verify that when they just open your timing marks on the flywheel line up, but all that really does is verify if your points should be set at 0.020" or maybe 0.019". Not going to make that big of difference on getting it to start.

I would verify the compression, just to put it on the "working" shelf with your spark. After that it must be fuel. I would mix up some gas and oil in a spray bottle and squirt some into the throat of the carb and see if that gets it to run a little. I can't really imagine why it wouldn't if your ignition is sparking and your compression is OK, assuming the coil plugs OR clips are indeed going to the right cylinders, because other then that it should run for at least a few revolutions, barring a couple of other rare conditions. Whether it runs or not, it would certainly tell you some interesting information.

Another thing to consider is how cold the motor is. Was the day you had it running considerably warmer then the day it did not? You seemed to have the feeling that the starter fluid was going to magically start this motor. If you have compression and timed spark, it should at least give you a few revolutions but after that these motors can be finicky. With my motor, on the cold days, I have to have the throttle fully open (to the neutral stop). Ignore the throttle grip marks for starting, just turn it all the way. When it starts, I have to put the choke in all the way. After a few seconds it wants to die and I have to open the choke 1/2 way back out, then it wants to die and I put the choke back in. This can go on a few times, depending on how cold the motor is. On a really hot summers day in the afternoon, it might not want any choke at all, but on the cold days you can't choke it enough, when starting it. By the way, be sure to take a look to ensure that your choke is fully closing when you pull out the knob.

The other thing to remember is on that cold day, I need my throttle fully open. What does that mean? It means that the throttle cam needs to be pushing on my carb roller the most it can. So if you think about it, if the alignment of my roller to throttle cam was even off by 1/8" (arrow 1/8" to the right of the roller when looking straight on towards the back of the motor) I am pretty sure it would be a complete bear to get started in the morning ... but would probably work fine in the afternoon sun.

 

[OptsyEagle]

Re: suspected timing issue on 74 15hp johnson, help!

Re: suspected timing issue on 74 15hp johnson, help!

When in neutral and I turn the tiller as open as it will go, the mark on the cam is to the left of the roller. (IE, when the tiller is as slow as it will go the mark is very far to the left of the roller). I dont think this is right from what ive read but im unsure. Any help would be greatly appreaciated.

I just re-read this. I don't know if you have already gotten around to fixing this but if my motor was adjusted where you say your's is, in the cooler mornings it would never start, and depending on how far the mark is to the left, it might never start. I could pull that cord until the cows came home and basically get nothing.

 

[someone11]

Re: suspected timing issue on 74 15hp johnson, help!

Re: suspected timing issue on 74 15hp johnson, help!

How do you know that? Timing is pretty much fixed by ensuring your point gaps are at 0.020", which I believe you did, and ensuring that the carb roller is aligned with the throttle cam, which I believe you did. I think you also confirmed that the spark plug boots and/or coil clips are all going to the right cylinder. That's your timing right there. You could put a multimeter on the points and verify that when they just open your timing marks on the flywheel line up, but all that really does is verify if your points should be set at 0.020" or maybe 0.019". Not going to make that big of difference on getting it to start.

I would verify the compression, just to put it on the "working" shelf with your spark. After that it must be fuel. I would mix up some gas and oil in a spray bottle and squirt some into the throat of the carb and see if that gets it to run a little. I can't really imagine why it wouldn't if your ignition is sparking and your compression is OK, assuming the coil plugs OR clips are indeed going to the right cylinders, because other then that it should run for at least a few revolutions, barring a couple of other rare conditions. Whether it runs or not, it would certainly tell you some interesting information.

Another thing to consider is how cold the motor is. Was the day you had it running considerably warmer then the day it did not? You seemed to have the feeling that the starter fluid was going to magically start this motor. If you have compression and timed spark, it should at least give you a few revolutions but after that these motors can be finicky. With my motor, on the cold days, I have to have the throttle fully open (to the neutral stop). Ignore the throttle grip marks for starting, just turn it all the way. When it starts, I have to put the choke in all the way. After a few seconds it wants to die and I have to open the choke 1/2 way back out, then it wants to die and I put the choke back in. This can go on a few times, depending on how cold the motor is. On a really hot summers day in the afternoon, it might not want any choke at all, but on the cold days you can't choke it enough, when starting it. By the way, be sure to take a look to ensure that your choke is fully closing when you pull out the knob.

The other thing to remember is on that cold day, I need my throttle fully open. What does that mean? It means that the throttle cam needs to be pushing on my carb roller the most it can. So if you think about it, if the alignment of my roller to throttle cam was even off by 1/8" (arrow 1/8" to the right of the roller when looking straight on towards the back of the motor) I am pretty sure it would be a complete bear to get started in the morning ... but would probably work fine in the afternoon sun.

The roller cam isnt lined up with the mark on the plate. That is one thing that I have to do when I get back. The difference between my motor and yours is that when i have fully open throttle in neutral the mark is 1/8" to 1/4" to the left of the roller cam. And when the motor was actually running a little it was maybe 80 degrees, when I tried to start it again after rebuild it was maybe 75 or 70.

 

[someone11]

Re: suspected timing issue on 74 15hp johnson, help!

Re: suspected timing issue on 74 15hp johnson, help!

So today I pulled the flywheel and the magneto plate or whatever you want to call it to adust the timing. The purple plate that touches the roller cam I pulled all the way in (as close to the flywheel as possible) and the mark still does not line up with the roller cam when the throttle starts to open. Something else must be off, or im missing something. There is a LOT of play beyond the twister. Like a half inch or so. I took some pics to show how off the timing is. Pictures show open throttle in nuetral.





Also, it was firing after I adjusted that plate a little, but never enough to start/run.

 

[Rick.]

Re: suspected timing issue on 74 15hp johnson, help!

Re: suspected timing issue on 74 15hp johnson, help!

Forgive me if your already way beyond this but you do realize the "mark" you want to align to is to the far right of the purple plate in you picture? I also woder out loud if you have the original carb and roller link? Best of luck. Rick.

 

[nwcove]

Re: suspected timing issue on 74 15hp johnson, help!

Re: suspected timing issue on 74 15hp johnson, help!

http://www.marineengine.com/parts/j...=15404G&manufacturer=Evinrude&section=Magneto

not sure how accurate the pics in the exploded views are....but that purple cam just looks wrong? and the part # on the carb doesnt match up? ( maybe im reading it wrong?) any chance it was used in its past life on a hydro....and modded a bit??? lol

 

[AlTn]

Re: suspected timing issue on 74 15hp johnson, help!

Re: suspected timing issue on 74 15hp johnson, help!

the mark you are looking for is to the right of the roller in the second pic...about the same distance as the width of the roller...there's an ad on ebay for an Evinrude/Johnson 74' 15 hp armature plate...the third pic shows this mark on the throttle control cam

 

[someone11]

Re: suspected timing issue on 74 15hp johnson, help!

Re: suspected timing issue on 74 15hp johnson, help!

I guess im using the wrong mark then. I didnt see any other mark on it. As far as I know this motor was not used for anything else and should be mostly original parts. I know the head was changed many years back and it has new points and anything I have done do it. Should be original carb though.

I wont be able to get to this until next summer now as im up at school. but keep throwing ideas out. This one has me stumped still. I have a feeling something is out of whack in it. Also, after the motor sat for a couple hours laying like on its "front" (propeller face down) there was a black substance/liquid coming out down by the propeller, what could this be?