holley 4150

[billysboat]

Still being new to this forum, your help has guided me to the next level of troubleshooting.
My motor is a new ford 351, along with all the accessories including a Holley 4150. After finding the source of most of my backfiring issues i.e. dwell, timing, firing order, wires crossed, etc. my focus is now on the carb.
The motor starts right up now with a real smooth idle, and will rev up only if the throttle is gradually increased. If I go to punch it, it will stall and try to choke itself out.
After reading many posts, it sounds like I blew the power valve due to the numerous pops and backfires that occurred during my time trying to fix the other issues I was having. Does it seem to you that this may be a power valve issue or something else with the carb? And, can anyone link me to a post or site on Holley Carb set up, rebuild or troubleshooting?
Thanks

 

[jtmarten]

Re: holley 4150

Sounds like the accelerator pump is not working. When you pump the throttle, you should have gas squirting into both primary venturi. If not you have an AP or blocked passage issue.
If its a new carb, I doubt the PV is blown. The carbs have a check ball that protects the PV from backfires.
Lots of great info on Holley's website, their tech guys are very good too.

 

[mkast]

Re: holley 4150

http://www.summitracing.com/parts/AED-7890/
Usually if a power valve ruptures, the engine idles high because of the extra fuel dumped into the carburetor body primary venturis.

http://www.summitracing.com/parts/HLY-717-7/
The correct carburetor fitting.

http://www.summitracing.com/parts/SUM-G1419/
Cable attachment.

 

[billysboat]

Re: holley 4150

....so it seems the ac pump is working. I can see the gas squirting. And the idle is not too high. Are there any adjustments I can start with to see if anything would change?

 

[Bondo]

Re: holley 4150

Are there any adjustments I can start with to see if anything would change?

Ayuh,... Sure,... Right After you Rebuild it...
It's full of Crap,... Deal with it...

 

[JES233]

Re: holley 4150

Yuo may have the wrong size power valve in the carb.It should be 1.5" lower than engine vacum at idle.Most preformance Holleys come with a 6.5".

 

[billysboat]

Re: holley 4150

Ayuh,... Sure,... Right After you Rebuild it...
It's full of Crap,... Deal with it...

I'm guessing your being serious about rebuilding it. And being full of crap, and meaning it is full of crap that needs to be cleaned out.

 

[rodbolt]

Re: holley 4150

and not all 4150 carbs use a power valve.
I rebuilt one yesterday,kinda, that the metering block casting hasnt been machined to use a power valve.
its on a 4.3 that I installed 2 years ago in a crab boat.
the fuel is eating the aluminium block.
ill post pics of it next time its apart.
I am calling Holleys tech line monday to see about purchasing a new metering block and disscuss why this one is disentergrating.
I had to reuse it this time,for now, due to pots in the water and its peeler season.

 

[Bondo]

Re: holley 4150

I'm guessing your being serious about rebuilding it. And being full of crap, and meaning it is full of crap that needs to be cleaned out.

Ayuh,... If it Don't idle, the Idle Circuit is Plugged with Crap...

Tear it down, Boil it out, Blow it out,+ Rebuild it...

 

[Bifflefan]

Re: holley 4150

Just because no one has asked, What CFM is the carb? A 600 to 650 is all that you need. If you wnet crazy with an 850 then the problem is to much carb.
Also as its a 4150 thats an auto carb not a Marine one. No difference in function but safety is a concern.
While the accelarater pump may be working it may need adjusted to squirt sooner.
There are many Holly books on tuning, get one read it before making adjustments. Or have someone that is good with them work on it.
Holley's work good out of the box in 99% of the cases.

 

[Kevinmcm]

Re: holley 4150

Seems your true problem is when the "hole shot" happens correct? If thats what the problem is, try advancing the timing just a bit, nothing extreme, just a tiny tap. If you dont have carb problems this will take care of the sudden loss of power when put in gear

 

[Kevinmcm]

Re: holley 4150

Sorry, re-read your post, but advancing the timing will still take care of this.

 

[billysboat]

Re: holley 4150

.....My Mistake. It is a model #4160 marine carb 0-9015-1. 750 cfm. It also sits on an Elderock RPM Air Gap manifold.
The motor like I said is brand new with less than 10 hours on it. That is why I am going through it a little at a time trying to learn as much as I can to get it right.
My friends are telling me this boat should go 60 mph easily, once I get the bugs worked out.

 

[wca_tim]

Re: holley 4150

depending on how your engine is built, that's probably a lot of carb for that engine. but it could easily be a (correct) powervalve / jetting / accellerator pump / float height / timing issue... could just be jetted too lean... I would start by making sure the carb is clean, post what you're running for jets, put a vacuum gauge on the engine and see what you're pulling at idle (so you know which power valve to run), check that your timing is set right (and maybe just a tad conservative), then go throug hthe process of jetting the carb right...

 

[Bondo]

Re: holley 4150

750 cfm. It also sits on an Elderock RPM Air Gap manifold.

Ayuh,... Generally speakin',..
That carb is Way Too Big for a motor that size,...
And,...
That Manifold is just plain ole WRONG for a marine application...
I believe those are spec'ed at 1500-6500rpms...
You need idle to 5000rpms, Tops...

You need a dual-plane manifold to build torque, down low in the rpms...

 

[billysboat]

Re: holley 4150

Ayuh,... Generally speakin',..
That carb is Way Too Big for a motor that size,...
And,...
That Manifold is just plain ole WRONG for a marine application...
I believe those are spec'ed at 1500-6500rpms...
You need idle to 5000rpms, Tops...

You need a dual-plane manifold to build torque, down low in the rpms...

Thanks for your thoughts. I bought the boat like this. It's in a 17' donzi like speed boat. I'm guessing the guy I bought it from was trying to make it look good and go real fast. I did get it cheap!

 

[billysboat]

Re: holley 4150

Sorry, re-read your post, but advancing the timing will still take care of this.

I'm gonna take your advice and give it a try. I just adjusted the timing yesterday by the marks that were on the motor. I didn't think about moving it a little either way from those marks. Thanks

 

[bomar76]

Re: holley 4150

The Edelbrock Performer Air Gap is a good choice, but the Edelbrock Performer RPM is a bad choice. Two different manifolds that are often mistaken as the same.

The RPM version moves the power band way up 1,000RPMs, out of the useable marine range.

 

[jtmarten]

Re: holley 4150

Also as its a 4150 thats an auto carb not a Marine one. No difference in function but safety is a concern.

Sorry - wrong. I only use 4150 Marine carbs, can't stand the 4160 single inlet/transfer tube. The 4150 has dual inlets. The 4160 has a higher likelyhood of leaking at the transfer tube, especially after being taken apart.
Marine carbs have 'J' overflow tubes, different seals/bushing in the baseplate to prevent leaks, and run a bit richer than auto carbs.

 

[wca_tim]

Re: holley 4150

I'm a big fan of 4150 marine carbs, not so much a 4160. and as the poster above mentioned, a number of the 4150 series were made for marine use - there are only a few differences.

do you have any idea what the internals of the engine are, ie heads, cam, compression ratio? like posted above an airgap rpm is probably too much for a 350 as is a holley 750 - unless the previous owner built the engine to run in that range... they're matched pretty well together, just wondering if in fact the heads and cam are too...

Finally, I would be very suprised if just advancing the timing is the answer. Timing should be based on what the engine likes the best and determined AFTER jetting is just right. just set it for 28 or 30 degrees total timing and get everything else right first...

ps. an rpm airgap with a holley 750 is about perfect for a 383 or 400 marine engin..