I'm going crazy. Help!!!

[stashtrey]

Many of you have probably read some of my threads lately. I've been having one thing after another go wrong on me.
After replacing my carb with a brand new one... new Pertronix ignition conversion, all new igntion wiring, new fuel lines, new fuel filter, good gas, new plugs etc..... I'm still having problems.
Basically.... my boat starts up fairly easy. Once I get it going it sounds great... rev's great, idles just fine etc. My plugs are bright white and the engine sounds great.
Here's where the problem begins. I can give the engine a good push of the throttle and it sounds amazing. I can get the boat up to about 4,000 rpms roughly and once it get's to 4,000 rpm's the boat just bogs out.... sounds like the engine is not getting fuel. If I keep it around 3800 or so it runs fairly well and I can stay on plane.
Is this screaming 'fuel pump'???
Can a fuel pump be bad but still allow the engine to start, run great when not under a big load, feed the engine but still cause problems in the higher rpm's??
I'm just freaking confused here because the engine honestly runs great at idle... the timing is right on.... good plugs, good ignition that was just rewired, brand new carb that seems to be operating properly.
It's just when I give it a lot of throttle and try to get the boat up on plane.... the thing just cuts out. The engine does die.... it just sounds like it's choking.
Help me!!

[stashtrey]

CORRECTION:
The engine does NOT die. It continues to run when I back off the throttle. If I bury the throttle it just totally bogs out. No backfiring.... no popping etc. Just absolutely no power when I really get into it and even at the lower rpms it's just doesn't have a lot of power at all.

[slotracer]

how old is the gas? and yes you can have a weak pump.

[stashtrey]

The gas is new this year... about 15 gallons brand new in each 20 gallon tank I'd estimate. However... it sat all winter oustside and I didn't top the tanks off. I used a container of Stablize in each tank.
Could bad gas only show it's face at high rpm's yet still allow the motor to run great at idle and at low rpms?

[slotracer]

2 years ago at tower park a guy had gas that was about 6 months to a year old and some how got water in it. run great on the trailer but in the water no go. drained all the gas and put in new and it ran great the rest of the
weekend. bad gas does funny things. have you check your fuel filter also? what fuel pressure do you have?

[stashtrey]

I just replaced the fuel lines and put a wix filter in.
It's really odd... at times when I'm cruising along at 3500 rpms or whatever and the engine sounds decent..... I'll feel the engine come to life for a split second and pull a little... then it bogs out.
The only two things I can think of at this point is the fuel pump is failing but still good enough to feed the engine at low rpm's.
OR
My gas tanks are full of something and it's clogging the pickup?? These are original tanks out of a '77 Spectra. I don't believe they've ever been touched.
I did notice one thing recently when filling one of the tanks. It almost seemed like there was something inside the tank.... I tried to look down the hole but couldnt' see anything. I use a yard stick to check my fuel level and one of the tanks seems to have something inside that interfered with that stick.
Could the tank be coming apart from the inside????
I have no fuel leaks in the boat. It's always dry and no smell of gas.

[El Prosecutor]

Your fuel pressure is highest at idle and lowest at WOT - I would slap a guage on it after the fuel pump and see what the pressure is at WOT. Look at the spec sheet for your carb and see what it needs. My Edelbrock says it should be 5.5 - 6 at idle, and should never drop below 2 lbs at WOT. A simple guage is cheap and easy to get at Pep Boys or whatever and you can be sure before you spend the bucks and time on a fuel pump.

[Moneypitt]

[QUOTE=stashtrey]
Basically.... my boat starts up fairly easy. Once I get it going it sounds great... rev's great, idles just fine etc. My plugs are bright white and the engine sounds great.
There is the key, white plugs = lean.......Yes your fuel pump is dying, but put a pressure gauge on the line after the filter, just to be sure. You should have a fuel pressure gauge anyway, so do it now. It could also be a delivery problem associated with the tanks and/or plumbing, so you have to start to get some good info somewhere, and the fuel pressure is where to start. If you feel it is tank/plumbing associated, use an outboard type tank to test, hooked straight to the pump. If the problem goes away you know where to look, if it doesn't, you know where not to look. It is a process of elimination. MP

[rerfert]

Well at least your on the water :p I'll hopefully be shaking my project down next week.
Seriously other than the fuel pump not holding fuel pressure??
I have an inline clear plastic fuel filter so I can see the fuel headed to the carb from the fuel pump.
After you rule out fuel pressure....check total advance and then how old is the timing chain?
White plugs you say.....You did mention that you had some junk in the fuel lines already right?? Did you possibly get some junk into the secondaries on the carb?
Maybe you just need to open up the mixture screws?
I'm about out of suggestions,so good luck and let us know when you find the gremlins.

[stashtrey]

Thanks, guys.
I really appreciate it... as always. I don't know where I'd be without this board.
I'll pick up a fuel pressure gauge tomorrow.
What is the key sign that I have fuel pressure/pump issues when looking at the fuel pressure gauge?

[rerfert]

My Edelbrock says it should be 5.5 - 6 at idle, and should never drop below 2 lbs at WOT.
Quoting El Prosecutor This sounds about the normal.

[RCB19]

Low pressure at idle (below 5lbs) and low at WOT (below 5lbs). Pressure should be maintained at 7 to 7.5lbs at idle and WOT. Anything below this and I would start looking for some delivery issues.

[stashtrey]

Right on.
However... wide open throttle for me is not really possible as the engine completely loses it's momentum.... it starts gasping and choking at that point.
Hopefully it's just the fuel pump and I can replace it. If it's my gas tanks causing problems I think I'm in for some trouble. They are the old fiberglass tanks.
How can get to the pickups in my fuel tanks? They are glassed into my boat. Would I be looking at replacing them alltogether?
time for me to go to bed. I'm seriously obsessed with this lately. All I want is for the boat to be back to normal. Last season it ran like a champ all year.

[RCB19]

Ahh you have fiberglass tanks. I would ditch thoes things faster than a dime hooker. There is nothing good about them as they will always eventually cause a problem for you. This could be your issue and if it is you should be able to see clear evidence in your fuel filter and possibly the carb it's self. If things look clean in the tanks then most likely it is your fuel pump and then if that doesn't solve it I'd take a look at the calibration of your carb. Just another thought if your distributor has a advance mechanisim in it you might want to take a look at that to. Something might be broke in there and it might cause the symptoms that you have described. Personally I would lock the advance system out and set your total timing. There is really no need for an advance system on a jet boat.

[Cas]

could be the tank vents not allowing any air in. Simple test, pop open the tank lids and go for a ride....right after you install that fuel pressure gauge ;)
If it runs good, it's the vents.
next test, as was mentioned above, take a 3 gal gas (size doesn't really matter) can along with you so you can feed the fuel pump from the can eliminating the tanks.
If it runs good, it's something in the line between the pickup and fuel pump.
If it bogs out again, it's between the fuel pump and carb.

[stashtrey]

Interesting.
My old fuel filter looked pretty gummed up. Golden looking stuff at the bottom. I put a brand new filter in there today and replaced the fuel lines from the tanks to the filter and then from the filter to the pump.
The carb is a brand new Edelbrock Marine 750. According to their manual and a guy at Edelbrock....the carbs should be good to go without any adjustment.
How do the fuel tanks vent, cas? I haven't changed a thing since I got the boat aside from the little work I did this year after this whole problem started. It ran perfect last season. That leads me to believe it's something with the fuel delivery.
I think I'll get the pressure gauge and try that out.... if it gives me a low reading at idle and then an ever lower (I suspect none) at WOT.... it's gotta be the fuel pump.
My wife told me today that I need a new hobby.

[stashtrey]

RCB19- I don't think I have an advance mechanism on my distributor. It's the original Prestolite and I put a Pertronix unit inside to replace the points. There is nothing mounted to the outside of the distributor or attached.

[Cas]

depending on the type of filler and cap, the vents could be in the cap itself or it may have seperate tubes attached to the filler tube.
Bad vents will also show low fuel pressure just because the pump is unable to pump the liquid. Another thing that can happen with bad venting is the fuel lines will collapse and that's a tough one to figure out.
Hang in there, you're getting real close :)

[RCB19]

Pull off the dist cap and rotor. If you see springs in there you have an advance system. If you see no springs it is most likely a locked system. Set your total timing at 34 to 36 deg and be done with it.
However I would stick to diagnosing the fuel delivery issues first. Is your motor stock? If it is your carb will probably run "OK" out of the box. If your motor is not stock you will probably need to re-cal a few things on it to make it run correctly.
That goldish stuff in your fuel filter might be signs of the fiberglass tanks comming appart. They will eventually do that especially with the formulation of todays gas. You will get it dude. :D

[centerhill condor]

I like the "CAS" solution...best of luck and keep updating your progress.
thanks,
next test, as was mentioned above, take a 3 gal gas (size doesn't really matter) can along with you so you can feed the fuel pump from the can eliminating the tanks.
p.s. you were crazy when you got the boat! this is just an episode. :220v:

[SmokinLowriderSS]

Basically.... my boat starts up fairly easy. Once I get it going it sounds great... rev's great, idles just fine etc. My plugs are bright white and the engine sounds great.
Here's where the problem begins. I can give the engine a good push of the throttle and it sounds amazing. I can get the boat up to about 4,000 rpms roughly and once it get's to 4,000 rpm's the boat just bogs out.... sounds like the engine is not getting fuel. If I keep it around 3800 or so it runs fairly well and I can stay on plane.
Is this screaming 'fuel pump'???
Can a fuel pump be bad but still allow the engine to start, run great when not under a big load, feed the engine but still cause problems in the higher rpm's??
Had this exact occurence in 2002 in my Taylor, started at about 4,000 and worked it's way down over a day of tubing to about 2,700. Pulled the pri fload sight plug off, started it, and as soon as she left idle, the fuel level would start falling. Fuel pump would not feed enough to suply any decent RPM load.
Would have figured it out sooner if I had a fuel pressure gauge.

[SmokinLowriderSS]

Your fuel pressure is highest at idle and lowest at WOT - I would slap a guage on it after the fuel pump and see what the pressure is at WOT. Look at the spec sheet for your carb and see what it needs. My Edelbrock says it should be 5.5 - 6 at idle, and should never drop below 2 lbs at WOT. A simple guage is cheap and easy to get at Pep Boys or whatever and you can be sure before you spend the bucks and time on a fuel pump.
Running a mech fuel pump, I am running about 5.5psi at idle, and about 9psi at 4800 WFO.

[Cas]

Running a mech fuel pump, I am running about 5.5psi at idle, and about 9psi at 4800 WFO.
if the same thing is happening with trey's, too much pressure with the Edelbrock carb will also make it run like doodoo.
stash,
Since you're going to be putting a gauge in the fuel line, it would probably be a good idea to take a look at the gas coming out.
Get yourself a good sized jar, disconnect the fuel line at the carb and put it in the jar. Pull the coil wire so the engine won't start and then turn the engine over until the jar is about half full. Let the gas in the jar sit for a few minutes to see if you have any water, gummy crap and or little particles mixed in.

[Wet Dream]

Have you checked the floats? Maybe you're running the bowls dry at higher rpm?

[spectras only]

Stash , had 3 spectras myself .These boats [ except the 19' with aluminum] have the fire retardant glass tanks.My oldest was a 1972 and never had any problem with them. Spectra didn't use a separate vent like newer boats . They just used vented caps. Like Cas mentioned , open the caps [ either screw on Nicsons , or flip up caps] and give it a blast and see what happens. The vent hole is no bigger than 1/16th and can get plugged . Motorcycles have vented caps and have the same symptom if the cap not venting.I would install a merc type water separator unit ,since the AC unit spectra installed in the inner transom is way too small . The filter capacity in the bottom of fuel pump is even smaller and can fill up real quick with water !

[stashtrey]

WOW!
Tons of great info here. I hope you all know... I will be storing all this info in my brain for future use. HOpefully I can help someone else down the line when I'm a more seasoned veteran.
I think my first steps should be to buy an inline fuel pressure gauge, install that and then take the boat out again. I'll initially check the pressure at idle... then I'll open it up and see where the pressure is at when the engine starts cutting out.
THEN... I'll open my gas caps. They are the flip up style. I'll see if opening the caps makes any difference.
If I have no or little pressure when the throttle is open... and the gas caps open make no difference..... I imagine I need a new fuel pump.
If it comes down to the fuel pump.... would a Holley mechanical marine fuel pump be a good choice?
Seriously.... thanks again for the outpouring of help on here. It really is amazing and I really do appreciate it.
When I finally this thing worked out I'll take some pictures and hopefully meet some of you if I can make it out to a Laid Back Boaters gathering!!

[stashtrey]

Cas- I got a good look at the gas that was built up in the fuel filter canister yesterday when I replaced it. The canister had some orange/amber looking particles at the bottom of the can.... the gas had a slight orange look to it.
What should good gas look like?

[Cas]

a lot of gasolines have an orange tint and it would be a little tough to describe the color with text. When gas starts turning to the gummy goo, it will get quite a bit darker. If there was gummy goo on the bottm of the tank, the new gas will start to break it down and it'll mix in and or break it loose. If it just breaks loos, it can restrict the flow in the pick up, the shut off valves at each tank (if you have them), the tee, the fuel pump, the filter and the carb.
It can be tough to pinpoint the prob but it's just a process of elimination as so many have suggested.
I put a Holley pump on my engine a couple of years ago and have had 0 issues with it.

[stashtrey]

The old fuel lines seemed clean and weren't too hard. I even unscrewed the little elbow that comes out of the fuel tanks and checked that to make sure it wasn't obstructed..... they were clean as a whistle.
Well..... hopefully it's just the fuel pump. I'd pay $100 for this to just go away. I'm tired of this!!! I just want to do some cruising and enjoy the summer... not continually buy new parts. At some point I'm going to exceed the amount I paid for the boat with all the parts and things I keep buying. lol.
I've had my eye on a boat down in Southern California that is for sale. Looks extremely clean. 19' Hallet mini cruiser. Full stringers, new carpet/interior, fresh 460, beautiful gel/paint, fresh tandem trailer. I might test the market when my boat is running and see if I could get a decent amount and if that Hallet is still around I'd snatch it up!!

[rerfert]

Well..... hopefully it's just the fuel pump. I'd pay $100 for this to just go away. I'm tired of this!!! I just want to do some cruising and enjoy the summer... not continually buy new parts. At some point I'm going to exceed the amount I paid for the boat with all the parts and things I keep buying. lol. !!
Keep up the good work...It's just another $100 away.
I have more in rebuilding my current boat (21 foot 79 Omaga BBF)The purchase price was a whopping $800 with screwed up paperwork and the top of the motor missing.

[Sanger Pete]

I had the same problem with a sleekcraft that I had years ago--strong running to about 4000rpms, then crapped out lost rpms and sometimes died. Finally traced it to plugged screens on the bottom end of the fuel pickup tubes that ran from the elbow on top of the tank down into the tanks. No matter how much that little pump sucked, only so much fuel could get through, and it was not enough to support more than about 3000 rpms. Cleaned out/replaced the screens and it was off to the races.

[stashtrey]

Sanger Pete- How do I get to those pickups when everything is glassed in? I can remove the elbow at the top of the tank but I cannot get any further than that. Could I put an air hose into that elbow and blow the pickups clear and then siphon all the gas out of the tanks and hope I get everything?
The only other solution (if the fuel pump is not the problem) I can see is to replace the tanks.... which would really suck.... new Imco's are at least $700-800 for a pair and then we're talking about paying someone to install them and do it all right.
Anyone want to buy my boat?

[80Dimarco]

Hell mine doesnt bog at all, foot to the floor and I can't get it over 4k. Sitting right under 4k at about 61 MPH. I remember back in the day this boat doing somewhere around 80(was no GPS's back then) plus is eats gas like a MF'r, it seems like it eats much more than it should.

[bakerjet]

Hell mine doesnt bog at all, foot to the floor and I can't get it over 4k. Sitting right under 4k at about 61 MPH. I remember back in the day this boat doing somewhere around 80(was no GPS's back then) plus is eats gas like a MF'r, it seems like it eats much more than it should.
if i were you i'd check my tach.

[EMCAM]

here is what i say .i didnt read the other posts . Buy a cheap electric in line pump and see if it solves the problem.If it does put a manual pump back on . Lose the pertronix i used to sell them and they got returned all the time. Step up and put an msd system on it.

[rerfert]

Anyone want to buy my boat?
Is it still priced at??
I'd pay $100 for this to just go away. I'm tired of this!!!
And how long will you store it for me? :)
Seriously now First check if you even have a filter in there at all?? (take a piece of regular electrical wire and run it thru the fuel tube into the tank...if it stops at the bottom of the tube, I would say you still have some sort of screen.
...IF you can pour some Beryman's Chemtol carb cleaner into the fuel elbow let it soak some and then put some air pressure to the elbow,repeat the process if you need to. IMO The Beryman's Chemtol carb cleaner and air pressure will eat/clean up any junk you have clogging a filter.
If you are going to put air pressure to the tank ,thru the elbow...Make sure you have the fuel cap open...You don't want to be pressurizing gas.(not good)
Forget the replacing of the fuel tanks if they are aluminium or steel and not rusted....You can remove them and flush them with Beryman's Chemtol...I just did mine and they are spotless.

[80Dimarco]

if i were you i'd check my tach.
I believe the Tach in good, when I am out of water I can rev past 4k np, it's when I am in the water I don't. Any idea's?

[Squirtcha?]

Here's one for ya Stash. This happened to me and I'm too embarassed to tell all the things I changed before I found the $15.00 fix.
Symptoms were identical and when you hear what I found it just might make sense to ya.
At the time I was running a Holley 850 dp on a dual plane manifold. The boat would run perfectly at anything other than WOT or very near it.
It turned out that the fuel in the secondary (back) carb bowl would flow away from the jets when at WOT and the boat would essentially run out of gas. If you got out of the throttle for a second then eased back into it, it would be fine again until you stabbed it to WOT, then run out of gas again etc. etc.
I picked up a set of jet extensions and notched floats and bang! Problem solved.
Jet extensions $6.99 from Jegs
http://www.jegs.com/images/photos/555-15024.jpg
Notched floats around $10.00
http://www.holley.com/data/products/pictures/medium116-11.jpg
A boat that runs right?
Priceless.

[SmokinLowriderSS]

I believe the Tach in good, when I am out of water I can rev past 4k np, it's when I am in the water I don't. Any idea's?
Yea, need more HP. Engine is tired if pump work hasn't been done. Double-check tach to be sure. Didn't all boats do 80 before GPS? :cry:

[Squirtcha?]

Squirtcha, don't think they'll fit in an Edelbrock!
Rio
Whoops musta missed that part.
You sure they won't fit? :boxed:
That being the case..................I'd say he should go ahead and buy a different boat. This one can't be fixed.

[1975sleekcraft]

Have you checked the floats? Maybe you're running the bowls dry at higher rpm?
for me my primaries were working fine but once i hit my secondaries it would bog
and not go any faster.
for me it was a float level in my secondaries was set way to low!!
i could run all day if i kept it 3500 and under!!!!
alittle float adjustment and i was off to the races!!!!!!!!

[Jim Hall]

This site is amazing,if you wait long enough someone will end up having the same problem that your having. I have exactly the same thing going on. I made some changes over the winter, installed through transom headers and replaced the points in my YL 56 Mallory with a Pertronix unit.After first trip out this season it ran like stated above.I have gone through carb,checked for vacuum leaks and have changed secondary diaphram to no avail. I have 6-7 pounds of pressure at 4-4300 rpm. Yesterday after running I started thinking it my be dist. and pulled it down to where I could see the spring attachment points. The springs are attached but one is loose on post. Is this normal. Could it possibly be Pertronix unit since they are common in above scenarios? Also I did not think about gas vent I am going to check tonight.

[Sanger Pete]

I actually finally traced the problem with the plugged fuel pickup tubes by disconnecting the fuel line at the tank, running it directly down the fuel fills, duct taping the fuel fill cap down, and found that it ran perfectly. I had aluminum tanks that allowed me to unscrew the fitting and pull out the tubes to replace the screens, and then reinstall them.