insanity looming over non starting boat

[sweebs]

so I bought a boat that supposedly only had corroded battery cables and a "clicking sound" when trying to start, short version of story is that the motor was seized from apparently having sat idle for 8 years, so that new price-gauged oem starter from the local boat shop did nothing to help. Soooo, I tore into the motor, got down to where I had the heads off and voila, was able to get the rest of the reciprocating assembly to turn after removing rust from two of the cylinders.

got the heads cleaned up and new valves at the local machine shop, all new gaskets throughout, after numerous broken bolts and studs and retapping and cursing, where I'm at now is

NEW:starter,plugs, plug wires, cap, rotor, ignition sensor, coil, battery, thermostat, gas drained and brand new tank of gas, got spark, checked TDC #1 cylinder for ball park timing twice, checked fuel pump was pumping fuel, rebuilt carb and now can't get to start.

I'm so close after all this literal blood and sweat (not to mention repainting trailer, rewiring and new LED lights, rebuilding and recarpeting steps, and dealing with the PITA of getting a title and license on the trailer from a no title, no registration state), I'm at my wits end and nearly out of budget to do any more repairs.

I know starting fluid is made out to be a big no no, but with starting fluid I can get the motor to run for a few seconds. I do get spray into the carb from pumping throttle, best I can tell I do have spark, do have fuel, have tried removing grey tach wires from neg side of coil to no avail, have pulled the oil press wires off the sensor and jumpered them together, the shift interrupt switch is sitting where it should be in the valley of the mechanism.

I've spent every day since buying this thing researching troubleshooting, buying parts, wrenching on it in the blazing heat, changed shift bellow and lower cable while I was at it, and just want to get her on the water already!

Please help! thank you!!

 

[bigbob_FTW]

I've used starting fluid before. A little squirt won't hurt anything. If it won't pop you'll know to keep digging.

 

[ChrisCraftJohnny]

This is a very simple bit of advise:
Have you tried to set the throttle control a bit forward. To increase the amount of gas at start up.
Sometimes on my engine, when the engine is cold. It just needs that little extra "umph" to get her going.
We are so used to our fuel injected cars/trucks that we can sometimes forget about how carbs need some initial help to start the engine.

Also, Make sure the choke is on. (the plate that blocks the carb air intake.
When I bought my boat, the electric choke was bad. Making cold starts impossible.

Otherwise, sounds like you have an engine that wants to start.

 

[sweebs]

so I just now got the engine to run for up to 30 seconds and a time! by pouring a couple oz of gas into the carb she'll fire up, I see the fuel going down the barrels of the carb once the engine is running but it dies out after several seconds or if I give it gas with the throttle, I hear a sucking sound and then it'll die. Guessing some carb adjustment is in order, but I did carefully rebuild the carb and adjusted the new brass float per the instructions down to the mm/32nd".. But this is progress! Not get out on the water progress, but at least I know she'll run (a little bit)

 

[ChrisCraftJohnny]

What kind of Carb? Mercarb?
Where do you have the mixing screw(s) set?
Try 1-1/2 turns out from closed for initial start up/tune.

Are you sure you did not leave out any plug or ball when you rebuilt?
Also, did you carb-dip the carb? Blow out everything with compressed air?

One needs to go slow when rebuilding a Carb.

You are close, but if the Carb. was rebuilt correctly it should fire with the mixture screws out that 1-1/2 turns.

 

[sweebs]

I put idle screw in to gently bottomed and then backed out 2 turns, I'll try to adjust that next. When I ordered the carb rebuild kit (Mercarb) I wanted to order a new electric choke as when the cover came off there was a lot of black debris from what I can only guess is deterioration of the thermostat sping/coil but they were back ordered. I have now discovered that I can keep the engine running by manually adjusting the choke plate to more of a closed position with my hand so I think next purchase will be a new electric choke. Still trying to figure up why it won't keep running at lower engine speeds and why if I throttle up it wants to die as well. Trying to be somewhat considerate of the neighbors at this time as running on muffs in the driveway is anything but peaceful and quiet!

 

[ChrisCraftJohnny]

Had a feeling part of the problem was your choke.

Here is a test:
Be sure you are getting 12V to the coil with ignition on. Test the voltage.

Watch the choke plate. It should start to open very slowly and continue until fully open.
If you have no movement. Remove the electric choke. Noting what detent it is set on the Carb.
Then bench test the choke with 12V source. See if the bi-metallic spring starts to move when the choke is energized.
If no movement, you need a new electric choke.

If it does operate. The choke needs to be installed on the correct detent on the Carb. Go back to the engine and set the choke forward or back one detent.
(Depending on what you are trying to do. Have it open sooner or later.)

I met a guy once who thought to adjust the carb's mixture, you loosed the choke and started to monkey with it!

So one of your problems is def. either a bad choke or a mal-adjusted choke.
Bench test the choke first so you know for sure.


As far as your bad idle. You may have not cleaned out the idle circuits well enough in the Carb.
Did the Carb. have white boogers in the float bowl? A sure sign of ethanol contamination.
You may have a tiny hole in the Carb. blocked still.

You are not getting the proper air/fuel mix into the engine. That is why you can hardly start, idle and rev the engine.

And be sure you do not have any vacuum leaks. In the manifold or around the Carb.

 

[bigbob_FTW]

Second on the choke. Had to go beyond the recommended setting. Works perfect now

 

[flipbro]

Hey Sweebs what ya working on 4,6,8 cylinder.Have you done a comprestion test? Are you sure you got the valves adjusted properly? Have you put a pressure gauge to fuel pump to see if your getting around 5 to 7 psi from pump? Are all your filters new?How about fuel lines? I don't think choke is your MAIN problem. But do agree with the possible vacuum leak. Get some gas in a spray bottle get her fired up and see if you can keep her running with the spray. Just use common sense...

 

[Bondo]

I know starting fluid is made out to be a big no no, but with starting fluid I can get the motor to run for a few seconds.

Ayuh,.... That statement alone, tells ya the ignition is firin', but it Ain't gettin' good gas,....

Go back to the fuel system,... I'm guessin' the carb rebuild was a failure,....

 

[sweebs]

well if I could figure out how to reduce the file size of my photos I'd post some as the sorry state of the carb before cleaning and rebuilding was just pitiful, but the 2 mb limit has me blocked.

Very possible the carb rebuild was a bust, BUT, I'm very anal about what I've done mechanically to this boat as I obviously only want to do it once, but alas I am already prepared to tear into the carb again. I followed the rebuild procedure to a T, both written and video instructions, only thing I can think of to recheck is the settings of the new float I installed as it is a brass float and doesn't have the precise shape and markings to measure from.

I do need to check fuel pressure because beyond verifying that there was indeed fuel being pumped into and out of the fuel pump, I really don't know what the pressure is and perhaps it's not adequate, I have a new fuel filter coming, but the one I have now I removed and verified there's no blockage or impediment to flow.

It's a 4.3 Mercruiser, 1992 and the instructions I was following for this engine and the type of non adjustable valves indicated to simply torque the rockers to a certain setting (maybe 20 ft lbs, I'd have to reference) there was no other adjustments indicated.

The fuel lines have not been replaced by me anyway. I did pressurize the tank and emptied about 10 gallons of what looked like ice tea colored fuel from the tank and fuel lines and have fresh new gas in there now.

thanks for the help and suggestions, I really appreciate it! when I get time to get back at her, and get the new choke installed, I'll proceed with some more testing.

 

[Eric 3.7LX Alpha 1]

Did you use an air compressor also in doing the carb job? To blow thru the small passageways?

I usually like to put a length of hose on the fuel inlet to the carb and blow thru it (manually) while operating the float, make sure air is getting in there......and shutting off. A blockage in that inlet will keep the fuel bowl from getting gas.

 

[Scott Danforth]

use photobucket to post photos

 

[sweebs]

well the new choke didn't help anything at all, and actually now unlike the other day which with pouring some gas straight into carb, the egas ngine would run as long as I fiddle with the choke plate, gas was indeed going into carb on its own once engine was running, and with engine off I verified that the accelerator pump did pump gas when throttle was pumped. Now, no gas is pumped, engine only runs for a few seconds, backfires then dies (still having to pour gas directly into carb) and I even took top of carb off, cleaned the venturi again, checked measurements on float level and drop again, verified fuel was being pumped through fuel pump while cranking,, and no dice on it running. I am so at my wits end on this thing. Never buy a boat on Ebay because you can get straight up defrauded and the advertised Ebay Buyer Protection is literally meaningless.. I've worked day and night on this thing since buying it in June, all I wanted to do is go boating, all I've managed to do is spend tons of money and time and still have a useless boat. Feel like it's cursed or something

 

[littlerayray]

Sorry to hear I know it's a pain

 

[thekidd77]

I had a similiar problem with my boat, one spring it just wouldn't start, found that if I kept pumping the throttle really fast I could keep it running by manually squirting fuel in with the accelerator pump, so fuel was getting to the carb just not thru it

When I rebuilt the carb everything looked fairly good inside but it wasn't, the passage ways in the bottom of the carb below the jets were completely plugged with junk, had to soak it then blew forced air in it eventually got it so I could spray carb cleaner down a jet and have it come straight out where the nozzles in the veins bolt in

 

[thekidd77]

I should say that when I rebuilt the carb, at first I was focused on the jets and that all the little pin holes in the brass parts were perfectly clean, I totally missed the big passage ways in the bottom of the carb that connects all the little pieces together would be completely plugged with crap when all the little pieces weren't

 

[thekidd77]

I think by pouring gas in and getting it going and by messing with the choke at the same time you were able to create enough vacuum to suck some gas thru one of the passage ways that was plugged, but now some gunk has moved and completely plugged it again

I think that's what you meant when you said it doesn't pump any gas anymore, but If you meant that the accelerator pump doesn't pump gas anymore that's a different problem cause the accelerator pump has pretty much a direct feed from the fuel line and if it isn't getting fuel te whole carb likely isn't getting fuel

 

[garbageguy]

Sounds like a carb isuue, but have you checked the anti siphon valve? that may not be it, but you've done so much, and it should be pretty easy to do (if you have access to it). I sure hope you get it worked out

 

[sweebs]

On the carb rebuild what I did was follow along with the video on Mike's carburetor parts on youtube, many new pieces were replaced, all the others were cleaned and submerged in carb cleaner for hours before being reassembled, but with my luck, there's a possibility some passageway remains blocked that I possibly could have overlooked/not known to look for/blow out,,, on the other hand, I've never heard of an anti siphon valve so that's definitely could be a problem since it's not been inspected.