Frustrated! Won't rev up, 5.8L, been working on it a while!

[Haut Medoc]

Re: Frustrated! Won't rev up, 5.8L, been working on it a while!

Don,

Thanks again for the advice. I typed that wrong and meant to say I regapped the points, not the plugs. Plugs are new as of yesterday and are at .030.

I have printed off the fuel system checklist and will take it with me tonight. I will pull the vent hose to see if it is clogged and the fuel pickup hose to see if the screen is blocked. I sure do hope it is one of these that is the problem.

Mechanical advance on distributor seems to work fine.

Question, I know when I first got the boat I had to suck the old gas out of the tank and I had to take off the round cover on the top of the tank that holds the float. This was the only hole big enough to get my hose down in to suck it out. If I didn't get that selaed and tight when I put that cover back could it cause an issue? Fuel gauge is reading 3/4 full when tank is slam full so maybe my float needs adjustment (least of my worries).

I don't have a gauge to check fuel system but will see about getting one.

Thanks,

Jeff

Nope, but that is most likely near where the fuel vent hose is.........
There should be a fitting on the tank near the back where the fuel line that feeds the water separater goes from horizontal to vertical.....
That is where the anti-siphon valve should be & the pickup screen at the bottom of that tube.....

 

[fireicyhott]

Re: Frustrated! Won't rev up, 5.8L, 2 MORE HOURS INVESTED MONDAY NIGHT!

Re: Frustrated! Won't rev up, 5.8L, 2 MORE HOURS INVESTED MONDAY NIGHT!

Well I spent a couple more hours at the dock tonight. Here is what I learned, still not fixed.

Pulled fuel tank vent hose. It is clear.

Found out that anti-siphon valve is located in tank or at the 90 deg fitting at tank. I had to pull the float out so I could see in the tank. The fuel line that comes out of the tank is attached to a barb that is a 90 deg fitting in tank. Then goes inside and has the pickup tube (metal) down to the bottom of the tank. Could not get this 90 deg fitting off tank so I couldn't check for a screen at bottom of pickup tube. Ended up pulling line off water/fuel seperator and check the anti siphon valve. When I blew in opposite direction of flow it air would not go, when I sucked on it I could hear the flutter of the anti-siphone valve and gas would come out. So in my opinion (haha) anti-siphon valve works.

Noticed that the plastic line that runs from the Holley 4bbl back to the fuel pump was kinked near the fuel pump. Don't think it matters as I think this is overflow tube (according to book). Straightened it somewhat and it didn't make a difference.

Boat revs up great sitting at dock, sounds like a damn race car. Under WOT on lake it only runs about 28mph and is backfiring occasionally through carb. A couple of times at idle it actually felt like it missed and just quit. Almost like it ran out of gas. Had to push throttle forward to get it started.

I need to get a gauge to measure fuel pressure. Also want to do a compression check on all cylinders. Timing is spot on at 10 deg BTDC. Carb was rebuilt with mixture screws set at 1.25 turns out.

I will continue to go through Don S's list and take any and all suggestions. I was really hoping to find a clogged vent tube. Hate I can't get pickup tube out to see if there is a screen in there. There is a screen right at carb where the metal fuel line screws into carb and it is clean.

Any more ideas? Almost ready to take it to Lake Norman in Charlotte to Four Winns dealer. They probably wouldn't touch it since it is a 1990.

 

[Haut Medoc]

Re: Frustrated! Won't rev up, 5.8L, been working on it a while!

Who rebuilt this carb?.....
You will need to go through Don S tests to get to the carb.....
There are not alot of things that will cause backfire through the carb....
Lean fuel mixture....
Bad intake valve....
Incorrect or defective ignition wires.....
Moisture in dist cap.....
I feel for ya....​

 

[Don S]

Re: Frustrated! Won't rev up, 5.8L, been working on it a while!

Carb was rebuilt with mixture screws set at 1.25 turns out.

Those are only PRELIMINARY mixture setting for use while the engine warms up so you can adjust them to fit your engine.

 

[Don S]

Re: Frustrated! Won't rev up, 5.8L, been working on it a while!

EUREKA !!!!!​

Doesn't matter whether it is in gear and running or in neutral, won't rev over like 2K rpms.

Missed that sentence, but that is the key to your problem, and I would bet my paycheck that when you put the new points in you had an odd looking kind of a C shaped part left over.
It's the spring that follows the copper strip on your points. Without it, only the copper is pushing the point back together and it won't do the job by itself.
You need that C shaped return spring.

 

[MikDee]

Re: Frustrated! Won't rev up, 5.8L, been working on it a while!

EUREKA !!!!!​

Missed that sentence, but that is the key to your problem, and I would bet my paycheck that when you put the new points in you had an odd looking kind of a C shaped part left over.
It's the spring that follows the copper strip on your points. Without it, only the copper is pushing the point back together and it won't do the job by itself.
You need that C shaped return spring.

Man that sounds like it could be it! A coincidence, a few years ago, there was a boat at the marina that the owner tried to change the points on (he was a newby), it ran like crap, and all the marina mechanics gave up on it, and I offered to help, and as I was checking out the points, the guy asked me what this c-shaped piece of metal was? I said that's it! the piece needed to back up the spring pressure on the points, I put it in, and all was fine! The guy couldn't thank me enough, and thought I was a magician,,, lol

 

[fireicyhott]

Re: Frustrated! Won't rev up, 5.8L, been working on it a while!

Don,

I hope you are right! I will check that out. I think I saved everything that came with the new point kit and saved all the old stuff.

In your first post from last night you copied and pasted one of my original problem statements:

Quote: "Doesn't matter whether it is in gear and running or in neutral, won't rev over like 2K rpms"

Now it will rev up pretty nicely in neutral, this is after I tightened the points up from the original setting.

I will check out your second post about the odd shaped C spring.

THANKS FOR YOUR HELP. It will probably be Wed night before I can get to it again. Now I am wondering if I should put in the kit to eliminate the points. But that would add another variable plus I would have to solder those resistors in. Would rather get it running right with points (if possible) and then add kit.

Thanks,

Jeff

 

[fireicyhott]

Re: Frustrated! Won't rev up, 5.8L, been working on it a while!

One more thought, thinking out loud here. Not sure if this would be related to Don's Eureka thought and the points.

My tach has been acting a bit funny as in it reads sporadic and it is low by about 300 rpm. We used a infared tach with reflective tape and the boat tach was consistently low. But also the boat tach will get "stuck" in certain spots or not go over 3K.

Where does the boat tach get its signal from? Could this be related at all or is it completely seperate issue?

Now I can't wait to go see if I left the funny shaped "C" piece out of the points.

Jeff

 

[Haut Medoc]

Re: Frustrated! Won't rev up, 5.8L, been working on it a while!

The tach signal should come from the coil......
The pertronix may interfere with your ESA.....
Points have an unfairly bad name IMHO, once you know how to set them correctly they are very reliable......​

 

[MikDee]

Re: Frustrated! Won't rev up, 5.8L, been working on it a while!

I wouldn't bother with the electronic ignition , till you get the bugs worked out, new points set right are fine! I'm straining my memory, but I think that piece we're all talking about is actually a spring steel strap to be installed with, and help give tension to the points, without it the point tension is very weak. Why they ever designed it to be put together in pieces, I don't know?

By the way, you mentioned something about soldering in a resistor? Is this not the pertronics kit? I used the pertronics, and don't remember any resistor? But, your ignition circuit does have a built in resistor wire to the coil, this does not work with the Pert. system, you must remove the resistor wire, and find, & use a 12volt direct switched ignition source with it.

One more thing, your tach wire comes off the distributor (ground) terminal of the coil, just make sure the nut, and wires are tight, and not partly broken there.

 

[MikDee]

Re: Frustrated! Won't rev up, 5.8L, been working on it a while!

The tach signal should come from the coil......
The pertronix may interfere with your ESA.....
Points have an unfairly bad name IMHO, once you know how to set them correctly they are very reliable......​

Just to claify Haut, ESA means? Electronic Spark Advance? (none here, it's points) Or, Electronic Shift Actuator? if so, yes definitely, I'm not sure if there's a way to get around it?

 

[Haut Medoc]

Re: Frustrated! Won't rev up, 5.8L, been working on it a while!

Just to claify Haut, ESA means? Electronic Spark Advance? (none here, it's points) Or, Electronic Shift Actuator? if so, yes definitely, I'm not sure if there's a way to get around it?

I think its electronic shift assist....
But its OMC so I ain't really sure....
Only Mercs for me....

 

[Don S]

Re: Frustrated! Won't rev up, 5.8L, been working on it a while!

I think that piece we're all talking about is actually a spring steel strap to be installed with, and help give tension to the points, without it the point tension is very weak.

That's it, you would be surprised how many people would leave it out simply because they didn't know what it was or where it went.
Most points have them attached. When I was in Alaska, the only place to get points (Other than a Marine dealer) was NAPA, and they always had the seperate spring for the points in the Prestolite distributor.

 

[MikDee]

Re: Frustrated! Won't rev up, 5.8L, been working on it a while!

I think its electronic shift assist....
But its OMC so I ain't really sure....
Only Mercs for me....

ESA, I'm pretty sure it's like the Mercruiser, it grounds out the points momentarily as you shift into gear, if I remember correctly.

 

[Don S]

Re: Frustrated! Won't rev up, 5.8L, been working on it a while!

ESA, I'm pretty sure it's like the Mercruiser, it grounds out the points momentarily as you shift into gear, if I remember correctly.

Not exactly, the ESA (Electronic Shift Assist) kills the fire to half the cylinders, to slow the engine.
Merc just grounds out the ignition completely.

 

[fireicyhott]

Re: Frustrated! Won't rev up, 5.8L, been working on it a while!

Will check some more things wed night.

I stopped by boat shop today where I bought the points, distributor cap etc. to look at the "C" shaped piece of metal that follows the copper strap. I am pretty sure that I put that on with the new points. Will verify that on the boat wed night.

I want to also check the "insulator" that came with the new tune up kit. I don't recall putting that on the copper strap when I installed the points. If the copper strap did not have any insulator on it could it arc at high rpms causing problems?

If I can find my camera I will post a pic of the directions that came with the Sierra Pertronix kit that talks about the resisitors and diodes, it is for OMC owners only.

I truly appreciate all the help. I will figure it out with your help and maybe a mechanics help. Just in time for cooler weather! hahah

Thanks,

jeff

 

[Don S]

Re: Frustrated! Won't rev up, 5.8L, been working on it a while!

Are you refering to this:
Shift Assist Fix
or this.
Installation Manual

 

[fireicyhott]

Re: Frustrated! Won't rev up, 5.8L, been working on it a while!

Don,

I am referring to the "Shift Assist Fix" link that you have posted above. I have purchased the diodes and resistors from Radio Shack. I haven't really taken a hard look at this while in the boat to look for the grey wire where the diodes go.

Is this necessary when installing the Pertronix kit? I assume it is since it says for OMC owners.

I have been busy working on the other issue. I will hopefully get to work on the boat Wed night going through some of the suggestions on the list.

Jeff

 

[fireicyhott]

Re: Frustrated! Won't rev up, 5.8L, SUCCESS!!!!! FINALLY!!!

Re: Frustrated! Won't rev up, 5.8L, SUCCESS!!!!! FINALLY!!!

Hi guys,

I am so excited tonight because guess what, I fixed the boat tonight!!!! Thanks so much to everyone for the suggestions and especially to Don S. and MikDee for coming up with the fix.

It was running bad, missing, and backfiring through carb at WOT. It was Don's EUREKA about this that lead me to that fix and he was right:


Don S. posted:

I would bet my paycheck that when you put the new points in you had an odd looking kind of a C shaped part left over.
It's the spring that follows the copper strip on your points. Without it, only the copper is pushing the point back together and it won't do the job by itself.
You need that C shaped return spring.
__________________

Don S.

I went back into the distributor tonight and sure enough I didn't have the extra tensioner installed. The points didn't have enough tension to close under higher RPM!!! I actually put the old points on which had a much heavier silver metal spring rather than copper and now boat runs MUCH better.

I now get to 32 mph at 4100 rpm which is probably as good as this big boat will go. It is a 23' Sundowner 225 w/ Cuddy Cabin, 1990 model with 290 hrs on it. I now I could get more top end by changing prop but I don't want to lose any low end. Guess I could try the SS prop compared to the aluminum one i have on.

Anyway thanks so much for the help. Don you are da MAN!!!!!!!

Woohoooooo, can't wait to go out and have fun on it instead of working on it.


Thanks,

Jeff

 

[Don S]

Re: Frustrated! Won't rev up, 5.8L, SUCCESS!!!!! FINALLY!!!

Re: Frustrated! Won't rev up, 5.8L, SUCCESS!!!!! FINALLY!!!

Good thing that was it, I already spent my paycheck.

Now, is the time to install the Pertronix, not when it doesn't work. But it sounds to me like that will be a winter or spring project
Have fun