It runs!

Patchman

Patchman

Administrator
Staff member
Ran the boat yesterday for about 4 hours on Summerville. Seems to have a little off idle stumble, but clears out after that. Think I might pull the carb bowls off and look for trash in primary jets. Do they run power valves in marine Holleys? Any suggestion are welcome. Trying to make Saturday run to Welch.
 
duanehydro

duanehydro

Active member
Yes, it should have a power valve, how many inches of vacuum does the motor have @ idle? Also, you may want to change to a larger primary squirter, try moving the accelerator pump cam to the #2 hole and see if it helps. You can also change the cams as well, for more or less fuel delivered per pump.
 
B

blownt

New member
put a vacuum gage on it and see what the reading is at idle.  Whatever it is divide by 2 and get that power valve.  Example - if you have a reading of 15lbs then you need a 7.5 power valve.  Bigger shooters might help.  Do not go with a 50cc pump unless its pure race.
 
Patchman

Patchman

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Staff member
I definately will try the power valve. I"m converting over to electronic ignition tonight. I noticed the carb does not have float bowl site plugs like a regular Holley. I had it back fire through the carb when I first bought it. I didn't know if they had check valve to protect power valve or not. Carb looks like it has been replaced recently.Thanks for the help!
 
duanehydro

duanehydro

Active member
here is the pump cam kit, in case you need to fine tune...http://www.holley.com/20-12.asp

is this a spreadbore, by chance? they don't have site plugs. And I agree with the 50cc thing, the small pumps can be fine tuned with cams and squirters to work fine.
 
Patchman

Patchman

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It's not a spread bore. It is the marine 600 cfm vacuum secondary. Wish I could run automotive carb then I would have a couple to choose from. The dead spot is really strange in that you can bump throttle off idle and it sounds like a four cylinder. Wait a little while and it might clean up, might not. The power valve could be the problem, but the motor idles perfect unlike blown power valves in the past. When it decides to run, it is like some gave the other four plugs ignition. If you go from idle to half throttle or more, it runs like a top.
 
Patchman

Patchman

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Staff member
I believe it is a single plane. It is the factory marine intake. It's a little different than the street intakes. I'm going to pull off the bowls and look for trash.
 
Patchman

Patchman

Administrator
Staff member
Converted over to electronic ignition the other night, no difference. Pulled the float bowl off and it was clean. Checked the power valve and it too is good. The carb is a Motorcraft not a regular Holley like I thought. It helps when I pay attention. Tried to set idle mixture screws and they make a difference in idle but not the flat spot. About ready for another carb. Any other suggestions? No i'm not putting a chevy in it! Just get that out of the way before it has a chance to come up.
 
S

sturat

New member
bbf429 said:
Converted over to electronic ignition the other night, no difference. Pulled the float bowl off and it was clean. Checked the power valve and it too is good. The carb is a Motorcraft not a regular Holley like I thought. It helps when I pay attention. Tried to set idle mixture screws and they make a difference in idle but not the flat spot. About ready for another carb. Any other suggestions? No i'm not putting a chevy in it! Just get that out of the way before it has a chance to come up.
Click to expand...
I will have a QFT 750 for sale in a week or so. I know that does not help you right now but soon it may :smile12:
I have only ran it three times and this weekend will make four.
 
T

TahitiRat

New member
I dont know if you want to try it but I have holley 4150 650 if you want to borrow it and see if it helps your problem. I can bring it to welch
 
Patchman

Patchman

Administrator
Staff member
That would be most excellent! I can't get there untill mid saturday, but would be most appreciative. I really look forward to meeting everyone there.
 
T

TahitiRat

New member
Done, I will be in site 32, if not there I have the old black tahiti (project in progress). If you cant find me it will be in the back of my gray 4dr chevy pickup just grab it. Iran it last year it should be in good shape I will pull it out and make sure it is clean ond looks good still. Also I dont have a spare double inlet fuel line so if you have you should bring it
 
Patchman

Patchman

Administrator
Staff member
Great! I will roll up in a Blue F350 dually pulling Old hawaiin day cruiser( Also a work in progress). We are at #16, so I will look you up. Again thanks!
 
Patchman

Patchman

Administrator
Staff member
I might have the fuel line needed. If not then it's no big deal. I'll be there hesitation or no hesitation!Thanks!
 
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