1996 Evinrude V6 150 (60 deg) Looper Problems

[racerone]

Not normal for a V-4 like that to run rough !

 

[SusieQ 21]

Racerone,
I rechecked carb throttle plate synchronization. Throttle plates are completely closed. I found one discrepancy. The spark lever and throttle linkage was not properly adjusted.
After re-reading the procedure for spark/throttle pick-up point adjustment this morning, I think I may have adjusted it incorrectly. I thought the idea is was to be certain the timer base and carb linkage begins to move at the same time. The roller seemed to be properly adjusted to the cam. That said, I think I may have misadjusted the throttle linkage roller to spark lever, thinking they were to have 0 clearance at idle. Obviously, I shall go through the process again today.
Regardless of possible misadjustments, I started the motor. As usual, the motor started easily, with “quickstart” engaged. As usual, in idled around 1200 RPM until QS shut-off. The motor seemed to be running a bit smoother, although it still had a bit of a miss or cough (not certain of the difference). Once QuickStart shut-off, idle was reduced to around 800 RPM or so, and slowly continued to lose RPM until shutting down. But it did seem to run a tad longer.
Regardless of possible misadjustments, the motor seemed a bit smoother, but the end result (no low idle) was the same. It would stay running, only by manually advancing timing and carb linkage, but with a miss.
My conclusion is, since there seemed to be a little difference, further adjustment of the spark/throttle pick-up point synchronization is required, Whether or not, it’s a total cure, we’ll see.
Hopefully, you will think that I’m on the correct course. Comments would be appreciated. Thanks.

 

[racerone]

Yes on a motor in good condition there is clearance between cam and roller.----If throttle opens too soon , motor will stall.----They call it " throttle pick up timing " for a reason.----This concept has baffled folks for ages !!

 

[SusieQ 21]

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.

I would think your 17’er would scoot very well with one of those V6’s. Where are you located? Perhaps you’d like to add a 3rd member to your Evinrude V6 collection. Ha.

 

[SusieQ 21]

Yes on a motor in good condition there is clearance between cam and roller.----If throttle opens too soon , motor will stall.----They call it " throttle pick up timing " for a reason.----This concept has baffled folks for ages !!

I’m back on it. I’ll let you know the results. Thanks again.

 

[racerone]

It is an---Action Marine 17 with a 25" transom.-----Look it up on you tube.-------Rated for 150 HP and some running with 200 HP.-----Yes it is a small " go fast " boat.

 

[SusieQ 21]

It is an---Action Marine 17 with a 25" transom.-----Look it up on you tube.-------Rated for 150 HP and some running with 200 HP.-----Yes it is a small " go fast " boat.

Sounds like a lot of fun! Just be careful!

 

[racerone]

I used to have a 16' running at 54 MPH and this Action Marine 17 will not be a problem.

 

[Chris1956]

Susie, I have a '98 J150EXECD. That is a 60*V6 motor, and it idles real smooth. Anyone who says a rough idle is the nature of the beast, is ill informed.

I think your compression numbers are fine, as they are even. I think you will find and correct the cause of the motor's issues. It could be something as simple as a synch of the idle needles. 5 turns open is the initial setting only.

 

[jimmbo]

Yes on a motor in good condition there is clearance between cam and roller.----If throttle opens too soon , motor will stall.----They call it " throttle pick up timing " for a reason.----This concept has baffled folks for ages !!

The concept of the Spark being used to set the Idle Speed, goes over a lot of heads. They are thinking on what they did on cars/trucks to tune them

 

[SusieQ 21]

Susie, I have a '98 J150EXECD. That is a 60*V6 motor, and it idles real smooth. Anyone who says a rough idle is the nature of the beast, is ill informed.

I think your compression numbers are fine, as they are even. I think you will find and correct the cause of the motor's issues. It could be something as simple as a synch of the idle needles. 5 turns open is the initial setting only.

Thanks for the moral boost. I was beginning to wonder if 90 psi compression indicates internal issues. Although a few folks have stated the compression is too low, I've read (one of the manuals) the V6 Loopers have a lower compression than the CF models. Thought maybe reeds could be an issue. Btw, The car idle/air mixture was set at 5 turns, per the manual.

 

[SusieQ 21]

I’m back on it. I’ll let you know the results. Thanks again.

The following are the latest attempts to obtain a normal idle.

For the third time, I retraced my steps at synchronizing carbs and linkages. Per manual procedure, I re-checked timing pointer. It was right on. I checked throttle plates and synchronized carbs linkages. I set low idle and high spark advance timing using an OMC analyzer. I adjusted cam and roller and fine-tuned throttle pick-up timing. The end result was WITHOUT much improvement. As usual, the motor started easily and idled at 1200, although with a definite cough. The motor seemed a little bit smoother, but it still WOULD NOT idle once "quickstart" shut-off. It slowly continued to lose RPM and once below 700-800 RPM would just quit. I noticed I could keep it running by continuing to push the key switch for "quickstart" (fuel enrichment). That seems to indicate a lean condition. For what it's worth, I could also keep it running by manually advancing the timing in coordination with the throttle linkage, but it still coughed badly as RPM increased. Likely, the motor was better able to run at higher RPM with a leaner condition.

At this juncture, I'm NOT certain which direction to take. I"m starting to wonder if compression (90 psi across all cylinders) indicates internal issues, preempting consistent and smooth low idle. Although I visually inspected the reed valves through the intake manifold (when I had the carbs/throttle bodies off), I wonder if the reeds may be the cause of low compression, or it's simply a sign of age and piston ring wear. Although several folks have said, the compression is too low to run properly, it's hard for me to believe I can't achieve a low idle, however roughly it may run. I read in one of the manuals that V6 Loopers had slightly lower compression than other models. I realize that 90 psi may not be ideal, but it's hard for me to believe it's causing a NO idle condition. If that's true, and low idle could be obtained, regardless of low compression, then I surmise I definitely have an air / vacuum leak somewhere. If so, that would prompt a direction for future repair/s. Otherwise, I look for a replacement motor. Problem with that scenario is that the boat is not worth the cost of a new motor....and reasonably priced, used motors are a "roll of the dice"....very scary.
I talked to a local Suzuki dealer yesterday that had a couple used motors for sale (2 Yamahas and 1 Suzuki). What was funny was, although the motors were traded-in on new motors, the dealer claimed no knowledge of the hours on any of the motors....and there were no warranties offered. No thanks!

 

[racerone]

Reed valves have nothing to do with compression in the cylinder !-----Pushing in the key opens the fuel primer valve.---Pushing in the key does NOT activate " quickstart." ------Quick start advances ignition when engine is cold.

 

[Chris1956]

If the compression values are the same (within 15%) across the cylinders, the motor is good. A cough is usually a lean condition.

Note: When I installed my carbs, after rebuild, I needed to slide them on the throttle body until the spagetti seal was seated in the groove.

 

[SusieQ 21]

Reed valves have nothing to do with compression in the cylinder !-----Pushing in the key opens the fuel primer valve.---Pushing in the key does NOT activate " quickstart." ------Quick start advances ignition when engine is cold.

Racerone, Thank you for telling me that. I guess I'm still thinking 4-cycle, as in valves.
What initiates the Quickstart cycle? Is it strictly controlled by engine temp?
So, from what you have said, the problem is pointing more and more to a lean condition. Do you agree? If so, I'll again remove carbs and throttle body and re-examine. Obvious sources of air leaks, especially since I worked on them previously. Not certain what went wrong, but obvious something. Maybe carb warpage issue wasn't entirely corrected.
Thanks again.

 

[SusieQ 21]

If the compression values are the same (within 15%) across the cylinders, the motor is good. A cough is usually a lean condition.

Note: When I installed my carbs, after rebuild, I needed to slide them on the throttle body until the spagetti seal was seated in the groove.

I just replied to Racerone. Based upon what you both have said, I can rule out low compression as a source of the problem. Compression was 90 psi in all cylinders. It seems the problem is strongly pointing to lean fuel delivery. Btw, I seated my carb seals in the exact same manner as you described. In addition, I used a tiny bit of grease to hold the seals in place until carb was seated. That said, I think it's time to remove the carbs and throttle body (again) in an attempt to find the problem. In retrospect, leaking carbs was the initial issue when I bought the beast. I have INCORRECTLY assumed all along, I corrected the fuel delivery problem during the rebuild. WRONG! Looks like it's "full circle"....back to the point of the beginning. Definitely my bad!
Many thanks.....much appreciated.

 

[racerone]

These motors have a hole in the side of the cylinders.----This hole bleeds off compression at idle and cranking speed ( compression test ) and makes for smoother idling.---Hence the 90 PSI from your testing.-----At high RPM there is not enough time for air to leak out of this wee hole !.-----

 

[SusieQ 21]

I want to say; regardless if I can get this motor operating correctly, I am VERY, VERY appreciative of the response I've received. Likely, most boaters have experienced the same or similar frustrations. That said, the response from this website and THT has been exemplary....particularly from the folks who have offered worthy information.....and, hopefully, you know to whom I'm referring!!
Please know, I've been working on this project (part time) for two years, and have been ready to call it quits on several occasions. Once again, the help and encouragement I've received is not only noteworthy but downright special. MANY, MANY THANKS!!

 

[SusieQ 21]

These motors have a hole in the side of the cylinders.----This hole bleeds off compression at idle and cranking speed ( compression test ) and makes for smoother idling.---Hence the 90 PSI from your testing.-----At high RPM there is not enough time for air to leak out of this wee hole !.-----

WOW! What a relief to learn that! I guess my new course will be to the lean fuel delivery issue!!
I wish I could repay you (and others) for your help. Thanks again and again.

 

[SusieQ 21]

These motors have a hole in the side of the cylinders.----This hole bleeds off compression at idle and cranking speed ( compression test ) and makes for smoother idling.---Hence the 90 PSI from your testing.-----At high RPM there is not enough time for air to leak out of this wee hole !.-----

Racerone,
You obviously have a lot of experience with these motors. Are you a trained tech or self-taught? Regardless, and for what's it's worth, I'm VERY impressed with your knowledge....and thankful for sharing it.
Again, I was told yesterday by a local dealer (and others), the problem with my motor is low compression. Those type of knee-jerk assessments are precisely why I initially chose to tackle my motor issues. Although I'm no mechanic, and have ZERO experience with outboards (until now), I thought I could do no worse than blindly searching for someone to work on this motor. Problem with my logic is; this motor is no small block.....ha! Honest, knowledgeable mechanics are very difficult to find. Thanks again.