so thats why that's happening!

[not enuf toys]

so this year has been an interesting year with my boat compared to last year. right out of the rip this year I have noticed several things that have been different since last year

~ lost approx 200-300 rpms
~ hole shot seems longer to plane
~ black grime on transom after use (progressively worse each time out)
~ little smoke and gas smell while at idle

since none of this was common from the previous years I though it was time for a basic tune up (plugs/wires). Nothing changed...infact over the summer it all got a little worse. Was starting to think it was time for a carb rebuild. kicked it around for a little bit as I was not looking forward to that with the advanced timing in the thunderbolt V and the need to adjust it in while on the water with a load.

so, fast forward to two weeks ago...same problems but some new signs - hard starting after sitting for a while and stumble/stall at low rpms. Ah ha! float issues! stuck or leaking float is allowing fuel to drop into the carb.

past sunday the wifey wanted to take the boat out and I said I needed to take care of this issue as it was progressively getting worse. removed flame arrestor and fired it up in the driveway. not to my surprise, fuel was leaking into the back of the carb (4 barrel weber) and dripping into the motor - I KNEW IT! however it was not because of a float. DAMN! WHAT IS DOING THIS???

keep looking around and the sight tube was filling up with gas and dripping into the side of the carb. Hmm
I squeezed the tube to see if there was pressure building up and it was - OK FUEL PUMP

so I ordered a new fuel pump (will be here tomorrow) and I am anxiously waiting its arrival. I will be installing this tomorrow night and crossing my fingers that I don't have any issues with the rod that controls the pump when I install.

so long story short - I am wondering, I am actually thinking and hoping that someone else here will agree with me when I say, that my issues that I have been having this year are all due to this fuel pump going out progressively. What do you think?

~ lost approx 200-300 rpms -- lost pressure through the jets = not enough fuel
~ hole shot seems longer to plane -- flooding from overflow of pump and lost pressure
~ black grime on transom after use (progressively worse each time out) - this ones easy = un burnt fuel from flooding
~ little smoke and gas smell while at idle = again un burnt fuel from flooding

whats your $.02 on this? am I going in the right direction or just hoping this is the underlying issue of the most of it?

 

[Bondo]

Re: so thats why that's happening!

so this year has been an interesting year with my boat compared to last year. right out of the rip this year I have noticed several things that have been different since last year

~ lost approx 200-300 rpms
~ hole shot seems longer to plane
~ black grime on transom after use (progressively worse each time out)
~ little smoke and gas smell while at idle

since none of this was common from the previous years I though it was time for a basic tune up (plugs/wires). Nothing changed...infact over the summer it all got a little worse. Was starting to think it was time for a carb rebuild. kicked it around for a little bit as I was not looking forward to that with the advanced timing in the thunderbolt V and the need to adjust it in while on the water with a load.

so, fast forward to two weeks ago...same problems but some new signs - hard starting after sitting for a while and stumble/stall at low rpms. Ah ha! float issues! stuck or leaking float is allowing fuel to drop into the carb.

past sunday the wifey wanted to take the boat out and I said I needed to take care of this issue as it was progressively getting worse. removed flame arrestor and fired it up in the driveway. not to my surprise, fuel was leaking into the back of the carb (4 barrel weber) and dripping into the motor - I KNEW IT! however it was not because of a float. DAMN! WHAT IS DOING THIS???

keep looking around and the sight tube was filling up with gas and dripping into the side of the carb. Hmm
I squeezed the tube to see if there was pressure building up and it was - OK FUEL PUMP

so I ordered a new fuel pump (will be here tomorrow) and I am anxiously waiting its arrival. I will be installing this tomorrow night and crossing my fingers that I don't have any issues with the rod that controls the pump when I install.

so long story short - I am wondering, I am actually thinking and hoping that someone else here will agree with me when I say, that my issues that I have been having this year are all due to this fuel pump going out progressively. What do you think?

~ lost approx 200-300 rpms -- lost pressure through the jets = not enough fuel
~ hole shot seems longer to plane -- flooding from overflow of pump and lost pressure
~ black grime on transom after use (progressively worse each time out) - this ones easy = un burnt fuel from flooding
~ little smoke and gas smell while at idle = again un burnt fuel from flooding

whats your $.02 on this? am I going in the right direction or just hoping this is the underlying issue of the most of it?

Ayuh,.... In the front of the block, in line with the fuel pump rod is a 3/8"-16 bolt hole.....

Lightly run a bolt in to contact the rod, holdin' it Up, 'n outa the way,...

 

[Silvertip]

Re: so thats why that's happening!

Finger tight only on that bolt. You don't want to score the push rod. Just enough pressure to hold the push rod against the cam.

 

[not enuf toys]

Re: so thats why that's happening!

I Had Been Reading About That Bolt Trick And Am Going To Try It.

So Does The Pump Sound Like The Root Of My Issues?

 

[slothman]

Re: so thats why that's happening!

yes it sounds like the pump is bad. that hose is there to get the gas back into the carb, so the bilge doesn't fill up with gas.

I tried putting a bolt in that hole to hold the rod and it didn't work lol. At a closer look, the hole was just close ended. It did not go through to the pump. I'm wondering if it's because my block is a 1995. Anyway, I had to use pliers and a flat head screwdriver to hold the rod, while I slipped in the fuel pump. God it was terrible !

 

[cliffblue]

Re: so thats why that's happening!

FYI - I used to pack grease around the push rod to hold it up. The oil would dissolve the grease, change the oil and you are done.

 

[not enuf toys]

Re: so thats why that's happening!

looked at it again last night - prepping myself for this afternoon and i am so glad i have tons of room to work there. HA!

this is going to suck and i will have Fred Sanford arthiritic hands when i am done!

 

[Eric 3.7LX Alpha 1]

Re: so thats why that's happening!

If the cam lobe that drives the fuel pump rod is down, you'll have a tough time getting the pump bolts started. You'll fight the spring pressure in the fuel pump.

Rotate the engine by hand and with your finger put pressure in on the push rod, and it will travel up as the cam lobe moves...... that's when you to install the pump, it will go in easy peasy.

 

[not enuf toys]

Re: so thats why that's happening!

done!

bolt trick - nope, hole does not go all the way through
grease trick - didn't even try
hacksaw blade trick - perfect!!

had a slight leak in one of the brass fittings. helps if I tighten all of the way...

taking her out tomorrow for a run. hoping, rather crossing my fingers that my issues this year go away! or at least aren't as bad!

 

[NHGuy]

Re: so thats why that's happening!

Keep a sharp eye on that brass fitting. We can't have gas in the bilge. Tighten it with flare nut wrench or you'll fudge it all up.

 

[not enuf toys]

Re: so thats why that's happening!

will do. when I first put in in I thought I had it in all the way (90 degree fitting that needs to point at about 1 o'clock to connect to the fuel line from the water separator) and had a drip from it (about one drip every 10 seconds while running). debated Loctite for quite some time. took the fitting off (while the pump was on) and ran it back in again. was able to get a whole other turn out of it (was quite tight and hard like when I first took it out of the original pump). drip was gone. ran my fingers over the fitting, ran a dry paper towel around it, still no drip. let the boat run for about 3 minutes and sill no drip.

I will how ever check it several times tomorrow.

Once all said and done I did notice it was running a little rich, or atleast it seemed to be as its hard to tell on a garden hose in the driveway.

 

[not enuf toys]

Re: so thats why that's happening!

if she is still running rich tomorrow would it be wise to twist back the idle screws on both sides of the carb just a few degrees or will the TV ignition just try and correct, over correct, under correct the spark time against the fuel ratio?