Gary Lewis Posted May 4, 2020 Share Posted May 4, 2020 I only did a leak down on #3 and #4. I just did #3 because I was curious on what a good leak down sounded like and the sparkplugs were out anyways. I did do a compression test on the rest and they were good, all 110+, just a fat 0 on #4 If you have the equipment and before you spend much time and money chasing the problem on #4, I'd do a leak-down on all cylinders. I thought I was going to freshen up the 460 in Big Blue, but discovered two cylinders with 47% leakage and no cylinders with acceptable leakage. Wanna buy a 460? Link to comment Share on other sites More sharing options...
Weberman Posted May 4, 2020 Author Share Posted May 4, 2020 If you have the equipment and before you spend much time and money chasing the problem on #4, I'd do a leak-down on all cylinders. I thought I was going to freshen up the 460 in Big Blue, but discovered two cylinders with 47% leakage and no cylinders with acceptable leakage. Wanna buy a 460? Well I'd have to get an actual leak down tester for that. I just took out the valve from my compression tester and just turned the air compressor down to 20psi. I just did #3 to see what a good cylinder would sound like and there was just a faint air leak vs a loud hiss. I got the head off and I'll post pics in a bit. Link to comment Share on other sites More sharing options...
Weberman Posted May 9, 2020 Author Share Posted May 9, 2020 Well I'd have to get an actual leak down tester for that. I just took out the valve from my compression tester and just turned the air compressor down to 20psi. I just did #3 to see what a good cylinder would sound like and there was just a faint air leak vs a loud hiss. I got the head off and I'll post pics in a bit. Sorry, never posted a pic of the valve. It did take a new one. Got everything back together and it wont start. Seems to be an issue with the carb. I look down in it and theres no fuel when I pull the throttle back. I checked and there is fuel getting to the carb. I sprayed some carb cleaner in and it hits a few times and then stops again. Time to do some research. Link to comment Share on other sites More sharing options...
Gary Lewis Posted May 9, 2020 Share Posted May 9, 2020 Sorry, never posted a pic of the valve. It did take a new one. Got everything back together and it wont start. Seems to be an issue with the carb. I look down in it and theres no fuel when I pull the throttle back. I checked and there is fuel getting to the carb. I sprayed some carb cleaner in and it hits a few times and then stops again. Time to do some research. Sounds like the needle valve in the carb is stuck closed. That would keep gas out of the carb. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted May 9, 2020 Share Posted May 9, 2020 Sounds like the needle valve in the carb is stuck closed. That would keep gas out of the carb. Sometimes I just fill the bowls up through the vent tubes. Maybe a minute or two of running is enough to get things flowing again? Link to comment Share on other sites More sharing options...
Weberman Posted May 9, 2020 Author Share Posted May 9, 2020 Sorry, never posted a pic of the valve. It did take a new one. Got everything back together and it wont start. Seems to be an issue with the carb. I look down in it and theres no fuel when I pull the throttle back. I checked and there is fuel getting to the carb. I sprayed some carb cleaner in and it hits a few times and then stops again. Time to do some research. Unless it has to be 100% back together, it still doesn't spray. I took the top off and cleaned the valves and made sure they opened. Even lifted the top off some while the pump was on and fuel came out and filled more. There was fuel in the bowl when I took it off. Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted May 9, 2020 Share Posted May 9, 2020 Unless it has to be 100% back together, it still doesn't spray. I took the top off and cleaned the valves and made sure they opened. Even lifted the top off some while the pump was on and fuel came out and filled more. There was fuel in the bowl when I took it off. So the carb is full or fuel, just none is getting through. Have you ever rebuilt a carburetor? Link to comment Share on other sites More sharing options...
Weberman Posted May 9, 2020 Author Share Posted May 9, 2020 Unless it has to be 100% back together, it still doesn't spray. I took the top off and cleaned the valves and made sure they opened. Even lifted the top off some while the pump was on and fuel came out and filled more. There was fuel in the bowl when I took it off. Yeah the carb is full in the bowl, just nothing when I pull the throttle all the way back. I took all of the boosters I think they're called off real quick and ran some welding wire through them to make sure they're clear. It hits every now and then now, don't know if it was a side effect of me cleaning the boosters out or assembling it 100%. I haven't truly messed with carbs besides the outside stuff, only in my early 20s. Link to comment Share on other sites More sharing options...
Gary Lewis Posted May 10, 2020 Share Posted May 10, 2020 Yeah the carb is full in the bowl, just nothing when I pull the throttle all the way back. I took all of the boosters I think they're called off real quick and ran some welding wire through them to make sure they're clear. It hits every now and then now, don't know if it was a side effect of me cleaning the boosters out or assembling it 100%. I haven't truly messed with carbs besides the outside stuff, only in my early 20s. It sounds like the accelerator pump mechanism is assembled incorrectly. Do you have the check ball and weight in correctly? And, by the way, welding wire is much too hard to be running through the orifices in a carb as it can enlarge the orifice. I use a strand of very soft copper wire. Link to comment Share on other sites More sharing options...
Weberman Posted May 10, 2020 Author Share Posted May 10, 2020 It sounds like the accelerator pump mechanism is assembled incorrectly. Do you have the check ball and weight in correctly? And, by the way, welding wire is much too hard to be running through the orifices in a carb as it can enlarge the orifice. I use a strand of very soft copper wire. I noticed something in there when I had the top off but didn't look in there to see what. Im guessing that when I just set it to the side when I had the head off that some of the fuel left varnish and that's it problem. Idk why else it would work fine and then just stop. Link to comment Share on other sites More sharing options...
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