1996 Evinrude V6 150 (60 deg) Looper Problems

[SusieQ 21]

I bought boat/motor two years ago. It had NOT been used for about 8-10 years. That said, I thought I was prepared for some work. Little did I know.
Before attempting to start, I fogged the motor and made certain the crankshaft freely rotated. After a few basic tests, I found the motor had no spark and several of the (6) carbs were leaking. Compression is 95 - 100 psi across all cylinders. I replaced almost all of the ignition system, including optics sensor, power pack, coils, wiring, plugs....and rebuilt all 6 carbs, including cleaning and installing a new throttle body to manifold gasket. Although I did not remove the intake manifold, I visually inspected the reed valves and they appeared to be almost new. I set the idle/air fuel mixture screws to 5-1/2 turns, only slightly richer than specified (5 turns) in the manual. Also per recommended manual procedure, I synched the carbs and linkages; set the timing pointer and set timing with OMC analyzer.
In addition, the following components have been replaced: fuel pump bulb, fuel filters, VRO2 pump diaphragm, choke switch, vacuum switch, thermostats, ignition switch, water pump, etc. I have tested the stator, timer base, and it's getting spark on all cylinders, etc.....all good. I have also tested the stop switch circuit.
The motor starts and runs roughly (1200 RPM), but quits after the "cold start" cycle completed....UNLESS I mechanically advance the timing (slightly) and the carb throttle linkage. Even with that, it still runs rough. I have tried manually actuating the choke while running, but it seems to make little difference. About the only difference noted is it runs longer after warm-ups, but NEVER well. If it idles down to 800 RPM or so, it stalls.
I should note, the boat is still on the trailer, so all testing and work has been performed with the muffs for water circulation.
I am convinced the problem is lean fuel delivery, possibly in conjunction with timing. I have tried propane around the carbs/manifold to see if it affects the motor (indicating an air/vacuum leak), but noted no difference in RPM.
I think it MUST be lean fuel delivery. Although the idle air/fuel mixture screws were adjusted to 5-1/2 turns after carbs rebuild (slightly richer than factory recommended settings), I intend to incrementally enrich the air/fuel mixtures to see if I can get some improvement. That said, it's hard to believe that a lean condition could make such a radical difference....but then, I'm not familiar with 2-cyle motors.
Any professional guidance would be appreciated. Thank you.

 

[Chris1956]

SusieQ, It sounds like you have done all the right stuff. Not sure what to add.

Spark plugs should be Champion QL78YC. Non-Q suppressors can interfere with ignition system.

Is the shift cut-out switch working? You might disconnect it and see if that helps.
I would set the idle mixtures to 5 turns out, just incase she is too rich.

You might check the idle timing 6*ATDC at idle, after Quickstart has turned off. To do that, I would pull the spark plugs and ground them. Disconnect the quickstart sensor (2 wire sensor on head), and crank the motor with the timing light. Perhaps the ignition analyzer has an issue?

About the only other thing that is a bit different on that motor, is the idle passages. The carbs have a "calibration Pocket". I assumed you cleaned that.

The throttle bodies have a cover over the idle needle. It has a gasket. If that leaks, that would be an issue.

There are incorrect carb kits for that motor as well. The spaghetti gasket between the carb and the throttle bodies are slightly different than thy should be. Since idle fuel needs to go from the carb bowl to the throttle body, before mixing with air, a leak there is an issue.

Finally, the plastic carb bowls warp. They have only caused leakage, as far as I know, but I am not an expert. The bowls do have the main jets installed in them, right? Many people replace the bowls and forget the swap over the jets.

 

[SusieQ 21]

Chris, Many thanks to your reply. I’m really exasperated! In response to your comments:

Spark plugs should be Champion QL78YC. Non-Q suppressors can interfere with ignition system.

Spark plugs have been changed 2X and are Champion QL78YC with new (gray, as specified) ignition wires.

Is the shift cut-out switch working? You might disconnect it and see if that helps.

Haven’t tested the cut-out. I certainly will try it.

I would set the idle mixtures to 5 turns out, just incase she is too rich.

My original setting after rebuild was 5 turns and starting issues, I readjusted to 5-1/2, which made no discernible difference. That said, I will return to 5 turns and try again.

You might check the idle timing 6*ATDC at idle, after Quickstart has turned off. To do that, I would pull the spark plugs and ground them. Disconnect the quickstart sensor (2 wire sensor on head), and crank the motor with the timing light. Perhaps the ignition analyzer has an issue?

I manually set timing with OMC analyzer. I checked idle timing with timing light (motor running) and it indicated 4-5 deg ATDC. It will try the procedure you recommended. Incidentally, I tried adjusting idle timing (a notch at a time (motor running) with no discernible difference.
NOTE: I need to mention that the timing base cover (not certain of proper nomenclature) seems a bit “sticky” at idle. I removed, cleaned, and added a very light film of grease to contact surfaces. I also very lightly tightened the retainer clips to prevent uneven pressure and possible frictional binding. It works better, but still a bit “sticky” in the idle position, although manual advancement seems to present no issues.

SusieQ, It sounds like you have done all the right stuff. Not sure what to add.

Spark plugs should be Champion QL78YC. Non-Q suppressors can interfere with ignition system.

Is the shift cut-out switch working? You might disconnect it and see if that helps.
I would set the idle mixtures to 5 turns out, just incase she is too rich.

You might check the idle timing 6*ATDC at idle, after Quickstart has turned off. To do that, I would pull the spark plugs and ground them. Disconnect the quickstart sensor (2 wire sensor on head), and crank the motor with the timing light. Perhaps the ignition analyzer has an issue?

About the only other thing that is a bit different on that motor, is the idle passages. The carbs have a "calibration Pocket". I assumed you cleaned that.

I’m don’t know specifically to what “calibration pocket” refers. I will research the term to be certain that was done. I believe I thoroughly cleaned all passages and blew-out with low air pressure.

The throttle bodies have a cover over the idle needle. It has a gasket. If that leaks, that would be an issue.

All seals were replaced. In addition, introducing propane didn’t seem to change idle RPM.

There are incorrect carb kits for that motor as well. The spaghetti gasket between the carb and the throttle bodies are slightly different than thy should be. Since idle fuel needs to go from the carb bowl to the throttle body, before mixing with air, a leak there is an issue.

Again, all new gaskets used during rebuild. As I recall, the Evinrude gasket kit came with two sets of gaskets (one brown and one black….I think). The differences seemed obvious and the same style (and color) gasket was used for each carb. Since I rebuilt the carbs 2 years ago, I can’t recall exactly which gaskets I used, but reasonably certain they were correct.

Finally, the plastic carb bowls warp. They have only caused leakage, as far as I know, but I am not an expert. The bowls do have the main jets installed in them, right? Many people replace the bowls and forget the swap over the jets.

I’m aware of warpage issues with carbs. I had a couple that were suspect. On those carbs, I sanded the bowls and side covers mating surfaces before assembly. In addition, I added fender washer to the side covers to help flatten the cover and apply even pressure. Most of the carbs were missing the BB in side orifice, so JB Weld was used to fill/seal the irifice. Lastly, all carb/throttle body components were torqued according to specs.

First, I can’t thank you enough for your response. I’m certain you detect my frustration.
Secondly, by your response, it seems a lean fuel delivery is the most likely issue, although I will test the "shift cut-out" and timing per your recommended procedures.
Although the propane trick didn’t seem to cause any RPM change, I will try again. Perhaps, an air/vacuum leak has worsened since I last did it. I’m also wondering if I should buy new carb bowls/bodies. Last I looked, the carbs were expensive, presuming they are even still available. Candidly, I hate to spend more $$ on this motor without reasonable certainty it will make a difference.
At this juncture, I guess I need to retrace my steps. Apparently I have overlooked something….or made a mistake in component assembly / replacement.
Please let me know if you have any thoughts. Thanks again.

 

[dingbat]

…

 

[dingbat]

Assuming setup on the same as my 200 hp your idle is set too low

Should be 750-ish in the water, in gear. Will idle 1200-1400 on a hose.

 

[jimmbo]

The compression numbers are quite low. Redo the Compression Test with a Different Gauge. Unless the engine is in good Mechanical Shape, it is never going to run well

 

[SusieQ 21]

Spark plugs have been changed 2X and are Champion QL78YC with new (gray, as specified) ignition wires.

Haven’t tested the cut-out. I certainly will try it.

My original setting after rebuild was 5 turns and starting issues, I readjusted to 5-1/2, which made no discernible difference. That said, I will return to 5 turns and try again.

I manually set timing with OMC analyzer. I checked idle timing with timing light (motor running) and it indicated 4-5 deg ATDC. It will try the procedure you recommended. Incidentally, I tried adjusting idle timing (a notch at a time (motor running) with no discernible difference.
NOTE: I need to mention that the timing base cover (not certain of proper nomenclature) seems a bit “sticky” at idle. I removed, cleaned, and added a very light film of grease to contact surfaces. I also very lightly tightened the retainer clips to prevent uneven pressure and possible frictional binding. It works better, but still a bit “sticky” in the idle position, although manual advancement seems to present no issues.

I’m don’t know specifically to what “calibration pocket” refers. I will research the term to be certain that was done. I believe I thoroughly cleaned all passages and blew-out with low air pressure.

All seals were replaced. In addition, introducing propane didn’t seem to change idle RPM.

Again, all new gaskets used during rebuild. As I recall, the Evinrude gasket kit came with two sets of gaskets (one brown and one black….I think). The differences seemed obvious and the same style (and color) gasket was used for each carb. Since I rebuilt the carbs 2 years ago, I can’t recall exactly which gaskets I used, but reasonably certain they were correct.

I’m aware of warpage issues with carbs. I had a couple that were suspect. On those carbs, I sanded the bowls and side covers mating surfaces before assembly. In addition, I added fender washer to the side covers to help flatten the cover and apply even pressure. Most of the carbs were missing the BB in side orifice, so JB Weld was used to fill/seal the irifice. Lastly, all carb/throttle body components were torqued according to specs.

First, I can’t thank you enough for your response. I’m certain you detect my frustration.
Secondly, by your response, it seems a lean fuel delivery is the most likely issue, although I will test the "shift cut-out" and timing per your recommended procedures.
Although the propane trick didn’t seem to cause any RPM change, I will try again. Perhaps, an air/vacuum leak has worsened since I last did it. I’m also wondering if I should buy new carb bowls/bodies. Last I looked, the carbs were expensive, presuming they are even still available. Candidly, I hate to spend more $$ on this motor without reasonable certainty it will make a difference.
At this juncture, I guess I need to retrace my steps. Apparently I have overlooked something….or made a mistake in component assembly / replacement.
Please let me know if you have any thoughts. Thanks again.

The compression numbers are quite low. Redo the Compression Test with a Different Gauge. Unless the engine is in good Mechanical Shape, it is never going to run well

I should mention; the compression was tested cold. That said, I will check again after motor has run and reached normal operating temp. Likely, the numbers will be a bit higher.
Thanks for your input.

 

[Chris1956]

If you sanded the carb bowls, and took off a bit too much material, the idle fuel pickup could hit the bottom of the bowl. That could clog it.

When I rebuilt my carbs two years ago, I ordered aftermarket carb kits. The gaskets looked fine, until I matched them with the originals. They were slightly different. I ended up sending those back and ordering another set, which was identical to originals. The first set (Sierra) was a direct crossover from the OEM gasket sets. The second set was also a direct crossover from the OEM carb numbers and also made by Sierra, with a different stock number. Not sure what happened...... If memory serves, I think the difference was the placement of the one or two small oring parts of the spaghetti gasket.

Hope it helps......

 

[SusieQ 21]

Chris,
Sincerely appreciate your continued responses.....REALLY!
When I sanded the carb bowls, I used a flat piece of hard material to assure level sanding. Although I think I got the surfaces level, I refrained from excessive sanding, thinking that gaskets would make-up deviations. Also, I was cautious not to remove too much carb material, knowing it could restrict the fuel pick-up. In addition, recall that I employed fender washers, as large as I could to fit within the limits of the side cover screws. Again, I did this to help apply even pressure to correct any deviation (in flatness) of the side covers. Although it's always possible level mating surfaces could continue to be an issue, I doubt that the fuel pick-up was affected. Since the leaks that I had were stopped, I'm now thinking the carbs aren't the MAIN issue, although they could still be contributory.
I also reset the idle air mixture screws to 5 turns. No difference. Certainly, once I get the thing to idle, I'll attempt fine adjustments, but I now doubt the adjustments are my main problem. I'll explain my thinking below and hope for your response.
The carbs kits that I used were in sealed Evinrude / BRM packages. The component parts appeared correct to my eye, seemingly matching the parts I replaced during the rebuild. That said, anything is possible, but I am now reluctant to blame the carbs....at least just yet.
After more fiddling yesterday, I discovered a few oddities. So, it's possible I have mislead you.....and myself.
First, using a piston stop tool per manual procedure, I rechecked the location of the timing pointer. It was spot on. Recall that I PREVIOUSLY used an OMC anaIyzer to set the timing. Since the timing pointer was correct, I assumed the low/high timing was set correctly. That said, I also visually checked the idle cam stop and linkages. I noticed that the timing base (cover.....nomenclature ??) was not resting completely against the stop at idle....but only slightly advanced. As mentioned previously, it's also sticks a bit near idle position. Note: This could also be an issue. While fiddling, I considered your comment regarding the possibility of a bad analyzer. So, per your suggestion, I checked the timing with a timing light. To my surprise, I found initial (idle) timing was significantly advanced about 12 degs BTDC. Keep in mind, the motor starts easily and runs (1200 RPM), until "quick start" shuts-off and RPM drops to below 800. I've read that "quick start" advances the timing by about 10 degs. Anyway, I opted to manually retard timing, but could only get it to approximately TDC after "quick start." I was at the far (forward) end of the timing tab, and it it still wouldn't idle. Too much advancement at idle could account for why it I can't get a low RPM idle. I'm perplexed why I can't get more retardation.....and why I would get so much variation between the timing light and the analyzer, unless one or the other is faulty.
Now, I'm thinking; the timing is not correct, contributory to a low idle speed. Whether the culprit is solely the timing (I know it sounds like it) or the problem is also in conjunction with misadjustment of linkage and/or throttle cable, low idle (RPM) needs to be increased...one way or other. I know the manually states that idle RPM is controlled solely by timing, but when "quick start" shuts down, the RPM drops to as point where I question that it's getting proper fuel delivery.
Today, I'm taking one last stab at synchronizing linkages and will recheck timing. I know for certain the carb throttle plates are synched closed, but need to check if plates are opening at low speed idle. Under normal operation, I'm assuming that the throttle plates open slightly (from increased vacuum) during "quick start," and then close slightly when RPM drops to normal idle. If so, it's possible, RPM may be the main reason why I can't get to idle, whether the problem is triggered by timing or linkage misadjustment, or both. I'm still bit perplexed with how to get it correctly timed, particularly considering I have lost faith in my analyzer and/or timing light. I know....as they said in the Army, "that's a problem for me and the chaplain." Ha.
One thing I've learned from this "Evinrude" experience: Regardless of the simplicity of a 2-stroke, this one is one fussy animal! It's seems whatever the problem(s) may be, they wouldn't impact operation to the extent is does. But, for sure, I'm no outboard mechanic.
Waddya think?

 

[racerone]

Only the maximum timing advance is set !-----Idle timing is the point where throttle plates OPEN.-----Actual ignition timing at smooth idle does not matter and looks after itself.-----Or hurry to a shop that can correctly set this up.

 

[SusieQ 21]

Only the maximum timing advance is set !-----Idle timing is the point where throttle plates OPEN.-----Actual ignition timing at smooth idle does not matter and looks after itself.-----Or hurry to a shop that can correctly set this up.

If that's the case with idle timing, then why is idle timing even adjustable? So, are you're saying that I need only to adjust max advance timing?
If engine stalls when throttle linkage is manually actuated, a lean condition must be the issue....or timing is not advancing accordingly. Correct? So, what's the reason I can't achieve a smooth idle?
Btw, I have called many local shops without success. Seems all are so busy, they won't schedule new work, and/or many simply won't work on old Evinrudes, citing difficulties obtaining parts and complexities with motors. I haven't found parts to be an issue, but will agree with time required to correct "complexities."

 

[racerone]

Agreed -----engines have too many wires and linkages and too many different motors.----Hard for shops to keep up.-----Idle timing is the point where throttle plates OPEN , so it is a throttle linkage adjustment.----On most motors the throttle plates are CLOSED for idling.---Retarding the timing is how idle speed is controlled.-----Make no adjustments until this concept is fully understood. f

 

[SusieQ 21]

Agreed -----engines have too many wires and linkages and too many different motors.----Hard for shops to keep up.-----Idle timing is the point where throttle plates OPEN , so it is a throttle linkage adjustment.----On most motors the throttle plates are CLOSED for idling.---Retarding the timing is how idle speed is controlled.-----Make no adjustments until this concept is fully understood. f

Thanks for your reply.
If motor runs at 1200 RPM during "quick start (QS)," and assuming carb throttle plates close when "QS" shuts-off, why does it stall? Or, are you suggesting, the throttle plates are not closing completely, prompting a "rich" condition? Note, I can keep it running (at 1200 RPM) when actuating the "cold start" with the key (indicating a lean condition), but I have to do it almost with continual "pumping." Is that due timing advancement or an enriched fuel delivery?
Sorry, to be so slow on the uptake, but I'm a bit perplexed.

 

[racerone]

I do not believe the ---" quickstart " ---System moves the throttle plates at all.----Quickstart changes the timing electronically.-----When you push in the key , the primer valve opens.-----This puts fuel directly into the engine.-----This fuel bypasses the metering circuits in the carburetors.----This would suggest the carburetion needs attention.----Make sure throttle plates are CLOSED at idle !----If throttle plates are not CLOSED the idle circuit does not work.

 

[SusieQ 21]

I do not believe the ---" quickstart " ---System moves the throttle plates at all.----Quickstart changes the timing electronically.-----When you push in the key , the primer valve opens.-----This puts fuel directly into the engine.-----This fuel bypasses the metering circuits in the carburetors.----This would suggest the carburetion needs attention.----Make sure throttle plates are CLOSED at idle !----If throttle plates are not CLOSED the idle circuit does not work.

Thanks. That makes sense.
I will check on throttle plate positions (and linkages) and proceed from there.
If OK with you, I'll reply with any success....or failure.
Thanks again.

 

[Chris1956]

Susie Q the motor you are working on represents the highest evolution of the 2 stroke, multi cylinder engine. It ran great and was reliable. The pollution controls doomed it. You will find the issue and fix it. I will chime in if I have anything of value.

 

[SusieQ 21]

Susie Q the motor you are working on represents the highest evolution of the 2 stroke, multi cylinder engine. It ran great and was reliable. The pollution controls doomed it. You will find the issue and fix it. I will chime in if I have anything of value.

That’s a very positive view of my motor. At this juncture, it’s difficult for me share your praise for it, regardless of accuracy. I admit; I have succumbed to a very low opinion of the machine. OTH, I’m certain the failures are mine….and not those of the motor. Perhaps, you may have more confidence in my ability than I. Nevertheless, many thanks for your continued support.
If interested, I intend to reply to Racerone, reporting my attempts made yesterday.
Thanks again.

 

[SusieQ 21]

I do not believe the ---" quickstart " ---System moves the throttle plates at all.----Quickstart changes the timing electronically.-----When you push in the key , the primer valve opens.-----This puts fuel directly into the engine.-----This fuel bypasses the metering circuits in the carburetors.----This would suggest the carburetion needs attention.----Make sure throttle plates are CLOSED at idle !----If throttle plates are not CLOSED the idle circuit does not work.

 

[racerone]

I picked 2 of these motors , one to use and one spare ( dealer trade ins ) a few years ago.----Weight of them was a huge factor for my 17' boat.-----At an affordable price.------No way that I can spring for a new 4 stroke.-----Hopefully they run as designed , nice and smooth.

 

[captmello]

I can't help with your issues, but just wanted to comment. I have a 4 cyl 60 deg looper and it idles rough. kind of like an car engine with a hot cam. i did the carbs and all the maintenance, compression is at 125 on all cylinders. I had a mechanic listen to it some years back and he said the rough idle was normal for my motor. it's been great for the 10+ year I've owned it. good luck!