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JaredOSU
06-19-2012, 12:00 PM
I have a 351 windsor with a Holley 4-barrel 4160 carb. I gapped the points to .018'' and timed it to 10 degrees BTDC. Are there any minor changes I can make to the carb without rebuilding it? Flow screws? Idle screw?

tex599
06-19-2012, 12:11 PM
You have two idle/air mixture screws on the side of the 4160, they should be out 1 1/2 turns. When was the last time you rebuilt the carb? This can be a source of a hard to start motor. You can get the rebuild kit for $45 and it is very simple to do takes about 2 hours. Just did mine and it made all the difference. Better idle, runs smoother and better acceleration.

thatsmrmastercraft
06-19-2012, 12:14 PM
Using a gap measurement to set the points is a rather crude way of doing it. Using a dwell meter is much more accurate and will provide better performance. To help with quick starts, replace the points and spark plugs every year. While it may seem excessive, it is cheap insurance. Replace the dist cap & rotor every two years, and inspect from time to time. Scrape any build-up from the electrodes.

As far as the carb goes, making sure the electric choke is set properly will help. They wear over time and eventually need some fine tuning - if not replacement of the choke cap.

You can clean the idle circuit by screwing in the idle mixture screws and counting the turns to lightly seated, then removing the screws and spraying carb cleaner (with the supplies straw) through the opening with the engine off. Replace the screws when completed to the original setting. This is usually about 1 1/2 turns out. You can fine tune to the highest RPM at idle.

Also inspect the accelerator pump function. Disconnect the throttle cable and with the engine off and the spark arrestor removed, work the throttle fully and look to see what the spray looks like in the throat of the carb. You will need to hold the choke open to do this. As long as there is a consistent spray from each side of the front half (primary) of the carb, you should be fine.

With the throttle re-attached, and the engine running, spray the carb cleaner around the base of the carb (use some caution as carb cleaner is flammable) and look for a rise in engine speed. This would indicate a leaking gasket in need of replacement.

JaredOSU
06-19-2012, 01:01 PM
It has been about 5 years since the carb has been rebuilt. Can I use a regular rebuild kit from NAPA? Or does it need to be a marine grade rebuild kit?

thatsmrmastercraft
06-19-2012, 01:05 PM
I always use a marine rebuild kit. There may not be a difference, but there isn't much price difference - especially if you shop online. I use Amazon a lot.

Voodoo
06-19-2012, 01:36 PM
I just rebuilt my carb with a kit from skidim.com, as previously indicated it cost about 45$ plus another 5$ or so for the base gasket. Having never rebuilt a carb, I went quite slow, took pics and took alot of notes and the entire effort pretty much ended up being a non-event. You'll need a source of compressed air. It was a good experience and the boat runs nicely.

Voodoo

thatsmrmastercraft
06-19-2012, 02:51 PM
While I am a happy SKIDIM customer, some items can be had for less money. I ordered my marine Holley rebuild kit through Amazon and had it delivered for $31.60.

tex599
06-19-2012, 04:46 PM
I will tell you to use the marine version of the carb rebuild kit. I tried using the generic 4160 from the auto store and the results were not great. The power valve is different as well as the gasket and the accelerator pump is a different size. It also has different needles and seats that will not work with the marine version. Most of the major gasket's are the same though. If you were just looking to replace the fuel bowl gasket's it would be fine. Also get a can of liquid carb cleaner (looks like a paint can) and let the secondary and primary metering blocks soak overnight. Lot's of little passages that can be clogged.

Gamble
06-19-2012, 09:37 PM
Having owned a 351w not too many years ago, the best thing I ever did was convert it using a mallory electronic ignition kit........I think others would agree that that would be a good thing to do. Just my .02. Won't cost a bunch and will provide years of more trouble-free enjoyment. PM me if I can help you.

thatsmrmastercraft
06-19-2012, 10:31 PM
Electronic ignition is a huge improvement over points ignition (contrary to one particular TT member:rolleyes:).

JaredOSU
06-20-2012, 12:22 AM
How do you set the dwell on a 351 windsor. I bought a dwell meter/volt/amp, and I was wondering how to set the gap. Do I still have to gap the points? And there has to be a semi-easy way of getting that engine on high-cam.

tex599
06-20-2012, 10:12 AM
Yes, you have to gap the points. Your dwell setting is related to the gap of your points. On my 81 351, my gap is .18 and the dwell is 31 +/- 3. The gap is easy, just remove the cap, bump the motor so the points rub block is on the high point of the nut your rotor attaches too. Take a feeler gauge and adjust the gap between the points. There is a set screw you have to loosen, be careful tightening it as you can strip it. You can also do a search on your tube and there are so good video's of it being done. Once you have your gap set, your dwell should be in range.

thatsmrmastercraft
06-20-2012, 01:06 PM
How do you set the dwell on a 351 windsor. I bought a dwell meter/volt/amp, and I was wondering how to set the gap. Do I still have to gap the points? And there has to be a semi-easy way of getting that engine on high-cam.

A large ratchet with a deep socket and a short extension on the crank pulley. Using a remote start switch works reasonably well as long as you have some patience. They are available for less than $10 although I think mine came from the Snap-On truck.