View Full Version : carb issue

05-13-2009, 09:05 AM
Hoping for a second opinion. I have a 86 S&S last fall I went to take here out for one last spin before I pulled the motor to repaint it and change water pump manifolds and gaskets. I was idling out and it just died. It would run fine around 1500 and up but not idle. So I figured I would worry about it in the spring. Well that time is here the motor is back in and I have taken the carb apart and clean out all the port as good as I can so far. I am still having the same issue. I was able to pull the carb the other night and spary some cleaner in for the third time and I thought I had it was able to get her to idle for like five minutes then she died again. I checked the mixture screws, one was 2 1/2 out and the other was 1 3/4 out. Since then I set them back to 1 1/2 out to try and start over but no luck. Once it warms up now I am having issues with trying to keep it running reved up. Should the fuel be dripping into to Pri. bowl or spraying. This is my first time messing with a Holley, I have messed with motor cycle carbs in the past just not 100% what the carb should be doing. I am ordering a renew kit. This carb is the 4160 right? I have changed the fuel filters the one in the pump had a lot of crap in it. I have also changed the cap but haven't put the points in yet. I just bought the boat this summer ran perfect then just died. Am I headed in the right direction vacation's coming LOL. Thanks

05-13-2009, 09:10 AM
Have you checked to make there are no vacum lines loose and also to make sure the gasket between the carb and intake is not warped and causing a vacum leak?

05-13-2009, 09:35 AM
I replaced the gasket between the carb and the spacer. But I never took off the spacer so the gasket between the spacer and the intake hasn't been changed. As for vacum lines there aren't any only PVC tube going to the spacer and the over flow going to the fuel pump from the flame arrester.

05-13-2009, 10:17 AM
Kit the carb and convert the points to electronic so you don't have to worry with points again.

05-13-2009, 10:32 AM
My thoughts on your carb issue:

1. Check for vacuum leak at the carb base by spraying around the base of the carb with carb cleaned. If the idle speed picks up momentarily there is a leak to deal with.

2. You asked about the fuel dripping or spraying into the primarys - you should see it spraying if everything is running well.

3. Your mixture screws should be set approx. the same number of turns out but not necessarily exactly the same. From that 1 1/2 turns out you should slowly work them out hoping to pick up some idle speed. If you don't, you need to keep searching for the problem. What have you done with the base idle speed screw?

4. Take your mixture screws out and inset the little straw on your can of carb cleaner into the opening and spray out the passage if you haven't done this already.

5. Jump back to other basics for a moment. How are the plugs, cap,, rotor, points (or do you have electronic ign.)? Is your fuel ok? A bottle of heat may go a long way.

6. At this point, if you haven't found the problem, you are probably ready to rebuild your carb.

Not an all inclusive list of what may be wrong, but will give you a few more things to do to help narrow down the possible problems to deal with short of a carb rebuild.

Good luck

05-13-2009, 11:00 AM
A freind of mine was having a similar problem with his Nautique (351 PCM) and it ended up being that one of the floats was full of fuel. So at higher RPM the engine would run, but as soon as revs were allowed to drop, it would flood out and die. We replaced the faulty float and changed the oil (because of constant flooding fuel eventually seeped past the rings and into the crank case) and everything was back operating as normal.

05-13-2009, 11:17 AM
If you have trash in your fuel filter you need to also check the in-line fuel filter/screen.
Just before the fuel line goes into the carb. Take the fuel line off. There is a small piece of screen in the line that would probably need cleaned as well.