Weird issue with adjusting idle stop screw, idle timing, etc...

[rusirius]

Ok, so long story slightly less long. First time I took my boat out this year a couple of times during the trip the alarm went off on the VRO for no oil.

It's a 1993 60hp Evinrude 913cc 3-cyl btw...

The friend (who I'm not quite sure still is at this point! LOL) I was fishing with said he had a buddy that works on outboards and was owed a few favors so if I wanted he'd have him take a look. I had a lot on my plate at the time so I figured sure, why not.

Buddy brings it back to me and says all it needed was a "tune-up"... When it was finally returned to me it was barely running. Would just BARELY start with almost full throttle and as soon as you backed it down it would die. I had never torn into this motor before, but had done a bit of work on some former outboards so I figured rather than chance sending it back to this idiot I'd just look into it myself.

Considering it's behavior the first thing I wanted to do was a link n sync, at least as best I could with it out of the water, figured I could get it close enough until I could take it out and get it fine tuned.

Coincidently as I'm looking it over to figure out what he could have possibly done to this thing, I notice the fuel line and oil line (both original) were hard and not in the best shape, I figure it was probably sucking air and that's probably the reason it was alarming in the first place. I replaced the lines and the primer bulbs. Pulled the VRO pump off and pulled it apart to check the diaphrams and all looked to be in great shape and very supple. Don't think there was any problem there.

So anyway...

This is the first multi-cylinder I've worked on, so I made sure to grab the service manual for it before trying anything. The bad part is, I have no idea what this guy did or didn't do, but I'm pretty sure he screwed things up pretty royally.

Right off the bat I notice that the throttle cable adjustment is tightened so that the arm isn't even hitting the idle stop screw and the carbs are actually cracked open when the throttle is set to idle. I'm pretty sure that's not right... So anyway, here's what I did...

The idle stop screw is turned all the way in, i.e. you can't turn it any further clockwise. I don't think that's where it should start, but the service manual doesn't reference it in any way, so I figured I'll leave it since I can't be certain.

I verify that all carbs are FULLY closed and open in sync. That was all good.

I pop the linkage off the throttle cam and adjust the cam roller so that the mark on the cam is pointing directly at the center of the roller with the carbs fully closed.

I push the throttle arm in (cable disconnected) until it's sitting firm against the idle stop screw and then adjust the linkage length until a piece of paper has a little resistance getting between the roller and cam, but still slides freely when the arm is against the stop screw.

I reconnect cable and verify idle holds this same position... Then at full throttle the pins on butterfly shafts are fully vertical. This was still good.

I start the motor back up but still it won't start in idle. I advance the throttle a ways and it starts, but as I pull it back towards idle the motor starts sneezing. I pull the cover off the carbs and notice the sneezes coming out the top carb. I back the mixture out a bit on this, once, twice, three times... Then it stops sneezing but now I notice some sneezing from the bottom carb as well. I back that one out a couple times and the sneezing stops....

I back the throttle down till it's running about 750rpm or so and it's idling good... Problem is, it's not set to idle... At 750rpm the throttle is advanced a bit... The throttle cam is in contact with the roller, roller is 1/8" or so past the mark and the butterflies are cracked open a bit.

Yet to try to pull the throttle back any further the rpm goes below 600 or so and it dies.

I'm guessing this is a timing issue, he probably also screwed around with the idle timing and advanced it too far maybe? If I recall the more retarded the timing is the higher the idle will be with butterflies closed?

So now that you have the back story, I'll get on with my questions... None of which I could find any answers for in a search, only hints here and there.

1) Should the idle stop screw be set all the way in like it is? Does it matter? Should I back it out like half way and then adjust the throttle cam linkage, etc? or leave it where it's at? The service manual references making sure the arm is against the stop screw before starting other adjustments, but it doesn't give a starting point for that stop screw.

2) Am I right in assuming with throttle cable hooked up, it should be adjusted so that the throttle arm is sitting flush on the idle stop screw and the mark on the throttle cam is pointing to the center of the cam roller with a slight gap between the roller and cam, butterflies closed?

3) If yes to the above, then I'm assuming my idle going to low and causing cut out is most likely due to idle timing?

4) Since I only have muffs, but really don't want to get into the water with an engine that's not running very well, is there a procedure for setting timing so I can get it reasonably close then adjust on the water? Can I just set it on muffs and assuming it'll be close to right?

5) Anything else I might be missing here? Something that either could be causing the issue or something that he might have screwed up when "fixing" my issue?

 

[flyingscott]

I would doubt he touched the high speed timing probably the link and sync is out of wack. When you did the link and sync did you do the low speed timing. Your idle speed needs to be set in gear and warm. Your idle on muffs will be around 1200 rpm in neutral lower in the water. If your motor has the quick start feature might be higher.

 

[rusirius]

I would doubt he touched the high speed timing probably the link and sync is out of wack. When you did the link and sync did you do the low speed timing. Your idle speed needs to be set in gear and warm. Your idle on muffs will be around 1200 rpm in neutral lower in the water. If your motor has the quick start feature might be higher.

No haven't done timing yet because I wasn't sure if I can do it (at least get it close) out of the water. I knew it would idle higher on muffs, but that's kinda what I'm confused about. As it is right now, the only way to keep idle above 600 (and keep motor from dying) is to have the throttle cable advanced enough to open butterflies, advance cam on roller a bit, etc. In other words, the throttle arm has to be off of the current idle stop screw setting (which is maxed as far as it can go in) about 3/8" to get it to idle at even 6-700rpm. I'm guessing that's because the timing is whacko?

 

[oldboat1]

couple of basic points -- want to be doing adjustments without remote cables attached (i.e., adjust the motor, then attach the cables to match motor settings). Also, think your rpms are low for running on muffs. Think your idle should probably be around 900-1000 rpms without back pressure -- so current idle will be low when you dunk it in the lake, maybe giving you stalling when shifting. JMO.

[oops. should have refreshed before posting. btw, sure the alarm is the low oil alarm? Thinking the water pump could be weak, overridden by use of muffs(?)]

 

[flyingscott]

The high speed timing is fixed and has no effect on the idle. The link and sync has a procedure for the low speed timing that's where the cam and roller need to come together. The low speed timing in the link and sync can be done on muffs get the manual. Why did it need to be worked on was it running bad. You also need to find out what he did to narrow down the problem.

 

[oldboat1]

might start over readjusting the idle mix screws. Might be stumbling rather than lean sneezing. Seat them, then open about 1.5 turns. Start engine, and adjust clockwise slowly (1/8 turn at a time) until you get the backfire (lean sneeze), then back out about 1/4 turn. Your bud's friend may have messed up the adjustment pretty good.

[Edit. Might be of interest -- engine rpms should increase as you lean out the mix screws (clockwise). At that point you would throttle down the engine, and continue adjusting the mix screws clockwise until the sneeze or stall, as above. Don't confuse the throttle stop adjustment (throttle) with the idle mixture screw adjustment (carb).]

 

[rusirius]

Well after having a few minutes to work on it this evening I'm even more baffled. Pulled throttle cable and verified link n sync. With throttle arm against idle stop screw there is barely a paper thickness between cam roller and cam, and it's lined up perfectly with the mark.

Starting engine required throttle ran up a bit. Once running reducing idle to about 700rpm still had butterflies cracked a bit (no where near hitting idle stop screw, and roller was well above mark on cam. Reducing throttle any lower resulted in engine dying.

So I got it as low as I could and started adjusting mixture needles on carbs. Started with first (top) carb.

Engine was already sneezing, and every sneeze I could see atomized fuel blow out the top carb and only the top carb.

Ended up being mixture screw up about a full turn to get sneezing to stop. At this point that would make that needle about 2 1/2 turns out from seated.

Once sneezing stopped from that carb I went on to middle carb. Turning in about an 1/8th at a time it seemed to have no real effect on engine. No sneezing and no notice change in rpms. Until finally idle got rough with one turn, then next 1/8th engine died. So I backed it out 1/2.

Then on to bottom carb. Same as middle. No change until 1/8th made it rough, then next 1/8th killed it. Backed out 1/2 and went back to top carb. 1/2 turn in and sneezing started again, again blowing mist out top carb throat with each sneeze. Backed off 1/4 and it was fine again.

But at this point again the rpms are still around 700, but throttle isn't anywhere near being closed. Attempting to close throttle any more cause stumbling and ad's engine dies.

I didn't have my timing light at this house, so I couldn't check it, but I figured I'd try retarding it a bit, which I thought would bring the idle up at that throttle setting.

Turned screw counter clockwise, which let timing plate move back toward rear, far as I remember that should be retarding idle timing, but it barely moved and engine died. Tried again to be sure it wasn't a fluke, but this time it backfired. After restart tried moving it the other way, which I think is advancing it, but it really didn't seem to make a lot of difference, but idle seemed to be getting higher as it advanced, which makes no sense. Very much and it just died. And it seems like it's already advanced way more than it should be. Hopefully tomorrow I can go grab my light from the other house, but I dunno. I'm very confused by this point.

Not sure if he just really screwed things up, or if there is some other sort of problem.

 

[ondarvr]

It's acting as it should, advancing the timing increases the RPMs, this is most likely your issue, you'll need to do a bit of adjusting everything to get it back to where it should be. A manual will cover the correct procedure if you want to speed up the process.

 

[oldboat1]

Well, a sheared flywheel key would throw off the timing (flywheel might have been removed, and not properly torqued). Also, backfiring through a carb can indicate a reed issue. Either one of those could make it impossible to tune.

Might want to start from scratch (compression test, spark test) and go from there.

 

[rusirius]

Well, good news and bad news... Good news is, I know what the problem is... Bad news is... I know what the problem is... Well, not the problem per se, but the result of the problem.

I stopped and grabbed my timing light from the other house today as well as my compression tester. Compression on 2 and 3 are 120psi... On 1 it's 95... I'm not happy about it, but that doesn't explain my issues...

So I moved on to trying to set timing... Clipped on and got the rpms set as low as I could while still keeping the engine running. Light showed about 750 rpm though it was bouncing a bit because of the rough running.

Hit it with the light and it's not even CLOSE to having solid timing. The mark was just a blur bouncing around all over the place. I need to research a bit in the service manual, but I suspect my next step is to pull the flywheel. For what it's worth, it doesn't look like it was removed, so I don't think it's anything the idiot did.

 

[flyingscott]

Lets address the the real problem you need to pull that head off fighting the low compression problem is like chasing your tail. Did you adjust the carb linkages if you loosen up the top and bottom carbs let them snap close then re-tighten. If you have butterflies open it will cause an idle surge. Do you have quickstart on that motor if you do that will throw timing around.

 

[rusirius]

I get what you're saying about the compression, and yes, I'll pull it down and rebuild this winter... but isn't it fair to say that even though 95psi isn't great it's not going to cause any major issues like what I'm seeing in the short term?

Yes it has quickstart, but if I recal advancing idle above like 1200rpm disengages it anyway. Either way, what I'm seeing definitely isn't from quick start. Or at least I feel very confident saying so... Here... I shot a quick vid to show just how insane we're talking here... I don't mean it's just moving around a few degrees... I mean it's not even close to being steady and ALL over the board...

https://www.youtube.com/watch?v=ezMyDwCCg_M

 

[jakedaawg]

Okay, the.light bouncing around is not the compression. It's one of a few things. Bad power pack, bad sensor coils, sheared flywheel key, or bad magnets or slipped mags in flywheel, or possibly more likely is an in advert ant firing of timing light due to interference from other wires on your pick up for the light.

With that said, these 60's are tough to link and synch when the comp is even. Compression issue must be addressed. You certainly can't get it good on muffs. Even with good comp. Must be done in the water. I can get them close in a baffled Marine run tank but not as good as in the lake.

 

[oldboat1]

If it were mine, I would pull off the flywheel and have a look. And as there is a compression issue, I would pull the head, with the optimistic assumption that you need to resurface the head and replace the head gasket. I would want to recheck the compression readings before pulling the head, but would not run it or even crank it until the flywheel is pulled, flywheel key checked and possibly replaced, and flywheel properly torqued back down. JMO.

 

[flyingscott]

Okay, the.light bouncing around is not the compression. It's one of a few things. Bad power pack, bad sensor coils, sheared flywheel key, or bad magnets or slipped mags in flywheel, or possibly more likely is an in advert ant firing of timing light due to interference from other wires on your pick up for the light.

With that said, these 60's are tough to link and synch when the comp is even. Compression issue must be addressed. You certainly can't get it good on muffs. Even with good comp. Must be done in the water. I can get them close in a baffled Marine run tank but not as good as in the lake.

Completely agree especially about the timing light pickup to close to another plug wire. That motor sounds horrible it sounds like it's running on less than 3 cylinders. If your timing was jumping that bad you would be able to hear it in how the motor runs you should have backfires and rough running.

 

[rusirius]

Okay, the.light bouncing around is not the compression. It's one of a few things. Bad power pack, bad sensor coils, sheared flywheel key, or bad magnets or slipped mags in flywheel, or possibly more likely is an in advert ant firing of timing light due to interference from other wires on your pick up for the light.

With that said, these 60's are tough to link and synch when the comp is even. Compression issue must be addressed. You certainly can't get it good on muffs. Even with good comp. Must be done in the water. I can get them close in a baffled Marine run tank but not as good as in the lake.

I'm going to try to get a chance to yank the flywheel today and check things out, possibly pull head too.

I pulled the plug for the sensor coils. No shorts to ground, but found something a bit strange. The service manual says the resistance of the coil (measured between the white wire and the blue, purple, green wires for each coil) should be around 600-800 ohms depending on meter. Either there's a bad misprint in the manual, or something is very wrong. I'm measuring about 9.7 megaohms on every coil.

And before anyone mentions it, I'm an it guy with an EE background, so I definitely know how to use a meter. Lol

With that said, if the sensor coils are that bad, I don't see how it could be getting spark at all, let alone run.

One more statement/question. I get what you're saying about interference on the light. But....

If it were triggering with interference, it would still trigger with the #1 no? I.e. Yes I might see ghosting in other places that make it appear to to jump around, but I'd still see a steady mark for #1 I'd think. And I don't. Not at all.

Further, if it were triggering off interference, the rpm readout on the light should be screwed, and it's not. It's fairly steady and agrees perfectly with the in dash tach.

What I can't figure out, is basically the same thing as said here. Yes it sounds terrible, yes it's running rough. But it's running. If the timing is truly bouncing around like that I just don't get how it can even be running at all. Lol

 

[jakedaawg]

While resistance is important the power pack that produces the spark functions on the voltage produced by the sensor coils. It's not the only voltage the PP uses but it does use it. I have had quite a few motors where the resistance was out of spec, not that far out, but out and they still ran. Do you have a DVA? What peak voltage are you getting from sensor coils?

Either way, I would be greatly surprised if you get an acceptable idle with those compression numbers. Even if all your electrics were good.

 

[rusirius]

No dva but I've got plenty of parts to slap one together, or I could just throw my tek scope on it. Either way I think I want to yank the flywheel first just to get a better look at things.

 

[Fed]

I'm measuring about 9.7 megaohms on every coil.

Good battery in the meter?
Will it read to zero in every scale setting?

CDI says it should read 38 to 42 Ohms, not sure how this paste will format...

Three Cylinder Engines (Without Quick-Start)
1979-2001 60-75 HP Models
Service Note: Please use the Factory recommended spark plug (currently Champion QL77JC4) gapped at 0.030?.
NO SPARK ON ANY CYLINDER:
1. Disconnect the Black/Yellow stop wire AT THE POWER PACK and retest. If the engine?s ignition has spark, the stop circuit has a
fault. Check the key switch, harness and shift switch.
2. Disconnect the Yellow wires from the rectifier and retest. If the ignition now has spark, replace the rectifier.
3. Check the cranking RPM. A cranking speed of less than 250-RPM will not allow the system to spark properly. This can be caused
by a weak battery, dragging starter, bad battery cables or a mechanical problem inside the engine.
4. Inspect and clean all engine and ignition ground connections.
5. Check the stator and timer base resistance and DVA output as given below:
WIRE READ TO RESISTANCE DVA (Connected) DVA (Disconnected)
Brown Brown/Yellow 450-550 150-400 V 150-400 V (*)
Orange Orange/Black 450-550 (CDI 45-55) 11-22 V 45-120 V (*)
White Purple 38-42 0.6 V + {1988 & newer 100-400 V (a)} 0.6 V + (#)
White Blue 38-42 0.6 V + {1988 & newer 100-400 V (a)} 0.6 V + (#)
White Green 38-42 0.6 V + {1988 & newer 100-400 V (a)} 0.6 V + (#)

 

[rusirius]

No Title

Well here's the latest. I pulled the flywheel this evening. Stator looks ok. Timing base not so much. I snapped a couple of pics, not sure how well it'll show up.

Basically a little over half of the way around the coils the plastic has been worn away by the flywheel core. It's ground down a bit of the exposed coil contacts. I'm guessing this was periodically allowing the flywheel too short out the sensor coils maybe?

What could cause this? If a bearing was failing wouldn't it have ground down all around not just on one side? Or is this normal wear on these?