What is the secret to tuning dual holley 4bbls?

[78Eliminator]

I bought my boat and it ran fine for one day. Ever since. it's had hard starting, terrible performance and today, an engine fire. Fuel was pouring all over my block form the second carb and eventually caught on fire. HELP! What to do?
78Elim(Justin)

[jordanpaulk]

Have you ever adjusted the float levels on the carb? If so, did you do it while the boat was on the trailer or did you do it when it was in the water with a cooler full of ice and silvers, like it would normally be run. Fuel pouring out sounds like a float problem to me. Just my .02.
Jordy

[78Eliminator]

Originally posted by jordanpaulk:
Have you ever adjusted the float levels on the carb? If so, did you do it while the boat was on the trailer or did you do it when it was in the water with a cooler full of ice and silvers, like it would normally be run. Fuel pouring out sounds like a float problem to me. Just my .02.
Jordy
Yeah, when I bought the boat, right after I hooked it up and was about to go, the PO said "if the carb floats ever stick, bang on it with a piece of wood". My name is Justin, and I'm a dipshit. I think that was a queue to rebuild them. Shit.
Remember that lame song: "Things that make you go hmmmmm"

[Hotcrusader76]

Hey bro,
If your pouring fuel out all over the place...where is it coming from? Is it pouring from the top of the vent tubes? (Then check fuel float level)...External leak? (Check throttle shafts)...Internal leak? (Power-valve is shot)
Tuning the carburetors to run in tandem is a science if done "correctly". Alot of people just throw them on and go. You need to ensure the booster venturies flow the same, and the air-bleeds as well. Without a flowbench, this can be time consuming.
If you need your carburetors rebuilt and dialed in, drop me a line. I can get them up to speed and definitly safer.
Just mention you are from ***boat.net and I can give you a the discount.
Thanks
V/R
Ty Lofstrom
Texas Performance Carburetors
sales@tpcracing.com

[Hotcrusader76]

Another note----
Don't bang on the side of the float bowls. If the fuel continues to pour out, it's most likely a obstructed needle/seat valve. If your having to dislodge crap inside, it's time to open it up and rebuild this carburetor.
Drop me an email!
V/R
Ty Lofstrom
Texas Performance Carburetors
sales@tpcracing.com

[77charger]

on a holley you can easily acces the needle and seat take it out and clean it or clear it.that should do the trick then adjust your float.To see the level remove the bowl caps on the side and raise til fuel comes out.(make sure carbs are level)
For simplicity remove duals and put a dominator!

[Snowboat]

Get the off road, spring loaded, needle and seats from Holley. They will keep the needle from ever sticking open and flooding, when going over rough water. If you can't find the number, shoot me an email.
[This message has been edited by Snowboat (edited June 30, 2002).]

[Hotcrusader76]

Originally posted by Snowboat:
Get the off road, spring loaded, needle and seats from Holley. They will keep the needle from ever sticking open and flooding, when going over rough water. If you can't find the number, shoot me an email.
[This message has been edited by Snowboat (edited June 30, 2002).]
I will have to disagree with you on the off-road needle and seat...Unless your running Off-shore in a heavy sea state...don't bother with this part. Save your money!
Ya'll that run your toys in the river or lakes..stick to the .110 Viton needle or larger. Save the off-road models for the ocean and mountains.
Just my 0.02...worth $17.89.
V/R
Ty Lofstrom
Texas Performance Carburetors
sales@tpcracing.com

[78Eliminator]

Originally posted by jordanpaulk:
Have you ever adjusted the float levels on the carb? If so, did you do it while the boat was on the trailer or did you do it when it was in the water with a cooler full of ice and silvers, like it would normally be run. Fuel pouring out sounds like a float problem to me. Just my .02.
Jordy
Jordy,
The guy who owned my boat before me didn't use it a whole lot. I think it's rebuild time. I think the carbs sucked a bunch of crap from the tanks and are full of debris. Does holley make good fuel filters?
Justin

[Snowboat]

Hotcrusader76; I think you are wrong. I don't build carbs for a living, but I can usually make them run OK. I have windowpane Viton needles. At 7 psi WOT, bouncing over waves on a windy lake, with my floats set at near the top of the spill hole, occasionally I would have stuck floats. Granted, they may only overfuel occasionally. If anything goes wrong with a cammed up v drive, and your wife and kids are in it without the husband/mechanic around, I say its cheap insurance.

[Hotcrusader76]

By all means...Safety is the added benefit! I agree with you 100% percent. But I took the comment at face value...the common "California" river go-er and Lake runner...mild to no chop.
But yes if your seeing mild to wild chop with a "flat-bottom"..then by all means...tame those floats.
Just curious...not to change the subject at all ....but what water temp do you run in, and what size jets do you run? altitude? engine specs? air temp?...I am an engineering major and I am researching some things in regard to water temp and fuel atomization....any info is appreciated...
V/R
Ty Lofstrom
TPC Racing

[Snowboat]

The boat is a 1981 Biesemeyer. Its a full roller 460 Chevy with 2.250 and 1.90 valves in Bowtie aluminum heads. 6-71 big bore 10% over and 14 psi boost at 4400 feet elevation. I'm waiting for lower gears but with 40's she is topping out at 6100 in the summer heat. I have 29's on the way from hulshot. As for the carbs-4779-2 750's, not referenced, still have choke towers, 50cc pumps on the primaries, 37 shooter on primaries, 35 shooter on the secondaries, 67's and 84's. The power valve is blocked off. Still dinking around with this and the water system. I got 91 on GPS last time out at 6100, and 6500 rpms on a warm day last November, 40 degrees. Says a lot for air temps. As they say on the other forums "I had a lot left in it". I didn't, it was floored, but the boat itself, has some more left in it. The boat has an Olson oil cooler and the water varies from 45 to 75. I've been experimenting with two bypass valves to increase engine temp but it is hard to find the right sweet spot. A couple more trips to the lake and I think I'll be able to keep the engine between 150 and 200. I can't keep the engine warm at 2000 rpms and still adequately cool at higher rpms. I'll probably have to settle for high rpm correct temps and let it run cool at low rpms. I'm going to Havasu and Parker next week with the family, and the family tug. Be snooping in others engine compartments, if they let me. No one in Wyoming to visit with. I may get myself a whipple intercooler for Christmas, because then I'll have thermostat provisions and 100 more hp.

[Hotcrusader76]

Snowboat,
Look me up...I am in McIntyre frequently, about 5 miles below Blythe. Not much space for the "egg-beaters", but cruise down anyways.
You might look into referenceing those powervalves. I have two different recipes for this type of work. Not easy modifications, but worth looking into.
Thanks for the info!
Ty

[gnarley]

Originally posted by 78Eliminator:
Jordy,
The guy who owned my boat before me didn't use it a whole lot. I think it's rebuild time. I think the carbs sucked a bunch of crap from the tanks and are full of debris. Does holley make good fuel filters?
Justin
The only way they would suck up debris from the tank is if there was no filter or fuel water seperator! Next if it sat for a while then the bowls dried up and when they got wet again some scale may have gotten loose and is now stuck in a needle & seat. NO PROBLEM! Do a rebuild and put them back on. It should not cost you more than $75.00. http://free.***boat.net/ubb/smile.gif
[This message has been edited by gnarley (edited July 02, 2002).]

[Jordy]

jordanpaulk:
Fuel pouring out sounds like a float problem to me. Just my .02.
Jordy Maybe I should get into the carb business. Then again, I'd have to learn a bunch of big fancy schmancy words. I think I'll stay put for now. :D

[78Eliminator]

Here is where it all started. Please read the entire thread and the last post by "Gnarley". Makes me sick to my stomach at how right he was and how Jordy also hit it right on the head with his first guess. Snowboat and 77Charger also agreed. Just aSimple float issue, nothing "scientific". I was a little intimidated with a brand new (to me) boat with dual 750s and Ty capitolized on it. In my experience with dual carbs, you have to vacuum sync them, and I had only done this with sport bikes and volkswagens so I left the whole thing up to a "pro". Anyway, I thought this was an interesting read.
Also notice who wanted to help, and who wanted to make a buck...

[Thunderbutt]

The gas might have caused your problem. The Holleys are easy to rebuild. Clean the carbs good. Drain the gas tanks. After the rebuild make sure you adjust the floats while its floting in the water.

[78Eliminator]

Thunderbutt:
The gas might have caused your problem. The Holleys are easy to rebuild. Clean the carbs good. Drain the gas tanks. After the rebuild make sure you adjust the floats while its floting in the water. Already did and it runs like a champ!

[Johnwithjm]

In the future you may want to try C&J for your carb problems. I use them all the time and the do great work. They have done carbs for one of my blown motors and also for my race motor. Never had any problems with C&J. They do alot of the race guys stuff.

[gnarley]

[QUOTE]Originally posted by 78Eliminator:
Please read the entire thread and the last post by "Gnarley". Makes me sick to my stomach at how right he was
:D OK Justin where's my five points? & I didn't even want to make a buck wink

[Blown 472]

Ty, I am curious as to what exactly you do to taylor the fuel curve. What are you modifing or changing?

[Jordy]

gnarley:
:D OK Justin where's my five points? & I didn't even want to make a buck wink I shot you a fiver for being helpful gnarley. :D

[gnarley]

[QUOTE]Originally posted by jordanpaulk:
I shot you a fiver for being helpful gnarley. :D
Right back at ya :cool: