Hey Guys,
First off I want to say thank you for all the great information within this forum, I have read a lot learned a ton!! Unfortunately I'm at a loss on where to go next so I'm looking for some advice.
I have a 1954 Fleetwin model 7516 I recently bought. The person I bought it from had changed the coils and condensers and cleaned the carb. He had the high speed needle dialed in but it was bucking like a bronco at low idle to mid throttle. He told me he had tested the compression and it was 72 on the top and 75 on the bottom. I put it on the boat it started on the third pull pumped water great and so I did a decarb the first weekend I had it. By the end of the decarb I was able to get it to still run good at high idle and started to settle down at low idle but was still bucking at mid throttle.
I took it home and pulled the flywheel, cleaned and adjusted the points with one of F_R's timing tools, and when I touched the ground wire on the top coil it broke at the connector. I replaced the connector put everything back together. I checked the pistons by slowly turning the flywheel against a plastic pen and no rod knock or anything rubbing under the flywheel. I then tested the spark with a tester and It was blue and jumped a 1/4 inch gap on both top and bottom. I put it back on the boat the next weekend expecting it to work great and I was able to get the low speed idle dialed back in but it but couldn't get the high. It still bucked at mid throttle and would bog down and no longer get up to full rpms at full throttle. It was like it was running on only one cylinder. I pulled the plugs (Champion JC6's) and noticed the top was oil fouled so I swapped them top for bottom , that didn't help so I tied another set of plugs I had they were NGK B6S's and the same thing happened it would idle, buck at mid throttle and bog down at wide open throttle.
Back to the bench! I put the spark tester back on before doing anything to see if maybe my point adjustments had come loose and it was still jumping a 1/4 gap. I checked all 4 plugs used over the weekend and all were sparking. So I tore the carb down. Inside it was clean enough to eat out of so I blew everything out real well replaced the cork float and put the new spring needle and gaskets on. I soaked the fuel filter and blew it out real well, cut a new fuel filter bowl gasket from some felpro as the old one was a little cracked and was off to the lake again! Got to the lake, it started up on 4th pull and no joy with the acceleration! I dialed the high speed in to where it would start to rev and back of, start to rev and back off. It finally caught and I ran it at WOT for about 10 minutes then when slowing down it bucked at mid throttle and idled pretty good at low throttle but wouldn't accelerate to full rpms again! I messed around with the needles and got it to hit full rpms two more times but it would never do it consistently, ultimately the needles always went back to the same settings when it would go but it wouldn't accelerate by just leaving them there. After the third time hitting wot I couldn't get it to do it again no matter what I did. Not knowing what else to do I pulled the bottom wire to just see if she would die, but it didn't. I put the bottom back on and pulled the top wire, it definitely ran a little smoother on one cylinder on the bottom than on the top. Plug's again black with oil after this weekends adventure but still sparking.
I run non-ethanol premium mixed at 16:1 with quicksilver full synthetic oil still on a pressurized tank that does not leak. My next thoughts are I either change the plug wires or maybe try to lean it out to to 24:1? I just don't know where to go from here so any help or suggestions would be appreciated.
First off I want to say thank you for all the great information within this forum, I have read a lot learned a ton!! Unfortunately I'm at a loss on where to go next so I'm looking for some advice.
I have a 1954 Fleetwin model 7516 I recently bought. The person I bought it from had changed the coils and condensers and cleaned the carb. He had the high speed needle dialed in but it was bucking like a bronco at low idle to mid throttle. He told me he had tested the compression and it was 72 on the top and 75 on the bottom. I put it on the boat it started on the third pull pumped water great and so I did a decarb the first weekend I had it. By the end of the decarb I was able to get it to still run good at high idle and started to settle down at low idle but was still bucking at mid throttle.
I took it home and pulled the flywheel, cleaned and adjusted the points with one of F_R's timing tools, and when I touched the ground wire on the top coil it broke at the connector. I replaced the connector put everything back together. I checked the pistons by slowly turning the flywheel against a plastic pen and no rod knock or anything rubbing under the flywheel. I then tested the spark with a tester and It was blue and jumped a 1/4 inch gap on both top and bottom. I put it back on the boat the next weekend expecting it to work great and I was able to get the low speed idle dialed back in but it but couldn't get the high. It still bucked at mid throttle and would bog down and no longer get up to full rpms at full throttle. It was like it was running on only one cylinder. I pulled the plugs (Champion JC6's) and noticed the top was oil fouled so I swapped them top for bottom , that didn't help so I tied another set of plugs I had they were NGK B6S's and the same thing happened it would idle, buck at mid throttle and bog down at wide open throttle.
Back to the bench! I put the spark tester back on before doing anything to see if maybe my point adjustments had come loose and it was still jumping a 1/4 gap. I checked all 4 plugs used over the weekend and all were sparking. So I tore the carb down. Inside it was clean enough to eat out of so I blew everything out real well replaced the cork float and put the new spring needle and gaskets on. I soaked the fuel filter and blew it out real well, cut a new fuel filter bowl gasket from some felpro as the old one was a little cracked and was off to the lake again! Got to the lake, it started up on 4th pull and no joy with the acceleration! I dialed the high speed in to where it would start to rev and back of, start to rev and back off. It finally caught and I ran it at WOT for about 10 minutes then when slowing down it bucked at mid throttle and idled pretty good at low throttle but wouldn't accelerate to full rpms again! I messed around with the needles and got it to hit full rpms two more times but it would never do it consistently, ultimately the needles always went back to the same settings when it would go but it wouldn't accelerate by just leaving them there. After the third time hitting wot I couldn't get it to do it again no matter what I did. Not knowing what else to do I pulled the bottom wire to just see if she would die, but it didn't. I put the bottom back on and pulled the top wire, it definitely ran a little smoother on one cylinder on the bottom than on the top. Plug's again black with oil after this weekends adventure but still sparking.
I run non-ethanol premium mixed at 16:1 with quicksilver full synthetic oil still on a pressurized tank that does not leak. My next thoughts are I either change the plug wires or maybe try to lean it out to to 24:1? I just don't know where to go from here so any help or suggestions would be appreciated.
