1984 Crusader 270 (but put in rebuilt long blocks about 6 years ago). Converted to electronic ignition.
Boat sat on hard during 2016, 2017 and 2018 (but started and ran for a bit in 2018).
Started okay and ran fine in yard (2019).
Launched (late July, 2019), started fine, drove across harbor, started to stall, but would restart. After a while wouldn't restart. Next day started, ran for while, quit.
Suspected contamination was clogging fuel filters. Changed filters. Ran okay for while. After about 10 minutes at cruising speed it quit. Thought maybe gas really bad and it clogged another filter, so changed again. Ran for a while. Swapped fuel hoses (so engines running off filter usually used by other engine). Problem seemed to transfer to other engine. (this test now suspect) Decided had to be fuel. Replaced filter again and ran both engines off other fuel tank. (other engine running fine so figure that tank and gas okay). (Note: fuel tanks pumped out in 2015 so all gas, except any residual that didn't pump out, is new.) Ran fine for about 15 minutes at 1000rpm, then another 15 minutes at 2900rpm, then quit. After half hour restarted, ran for about an hour at 1500rpm, then quit, wouldn't restart. Next day started but couldn't do extensive test.
Because they were old and I was desperate, replaced carb and coil.
Engine started, ran for about 20 minutes, including about 15 at 2900 rpm. Then quit. (Quitting usually involves loss of rpm over course of minute or so, total failure to rev back up, then stalls). After half hour started again but only ran for about 10 minutes at about 1200 rpm (wouldn't restart). After another half hour started again, ran for about two hours at 1000rpm (then I shut off as we were back. (We went on a trip, about 25 miles each way, this was the return home, didn't try to increase speed during those two hours, preferred to get as far as possible with two engines rather than risk losing one even though at slow speed).
Next day: started, ran about 15 minutes at 2900rpm, then started to quit. Switched hoses. Problem stayed with same motor so not filter (at least main one, there is a smaller one mounted to engine, replaced earlier but only first time). Have only been using one tank so both engines getting gas from same tank. Other engine running fine so fuel itself not problem.
Seems to be getting better in that it will sometimes go longer if speed kept low, but still won't go for extended period at cruising speed.
I put electric fuel pump in gas line (between filters) as a way to test if fuel pump (mechanical) was bad (although wouldn’t mechanical fuel pump be good or bad, not work for a while then need to rest?). Figured it would also pull gas through filter if it was partially clogged. Does not seem to make any difference.
I was going to try to test fuel flow at carb but don't have a way to do that without it going all over (hot) engine. Is there a gizmo that can be put at the end of the fuel line at the carp to measure gas pressure or flow? I did back the fitting off, gas came out, seemed to be under pressure which suggests no problem with the pump.
Only thing that makes any sense to me is clogged filter, but hose switch seems to eliminate that. (plus multiple new filters, which should still be clean since using other gas tank.) I don't know of anything else that affects a motor during use (other than sometimes a coil, but replaced that already). Any suggestions appreciated.
.
Boat sat on hard during 2016, 2017 and 2018 (but started and ran for a bit in 2018).
Started okay and ran fine in yard (2019).
Launched (late July, 2019), started fine, drove across harbor, started to stall, but would restart. After a while wouldn't restart. Next day started, ran for while, quit.
Suspected contamination was clogging fuel filters. Changed filters. Ran okay for while. After about 10 minutes at cruising speed it quit. Thought maybe gas really bad and it clogged another filter, so changed again. Ran for a while. Swapped fuel hoses (so engines running off filter usually used by other engine). Problem seemed to transfer to other engine. (this test now suspect) Decided had to be fuel. Replaced filter again and ran both engines off other fuel tank. (other engine running fine so figure that tank and gas okay). (Note: fuel tanks pumped out in 2015 so all gas, except any residual that didn't pump out, is new.) Ran fine for about 15 minutes at 1000rpm, then another 15 minutes at 2900rpm, then quit. After half hour restarted, ran for about an hour at 1500rpm, then quit, wouldn't restart. Next day started but couldn't do extensive test.
Because they were old and I was desperate, replaced carb and coil.
Engine started, ran for about 20 minutes, including about 15 at 2900 rpm. Then quit. (Quitting usually involves loss of rpm over course of minute or so, total failure to rev back up, then stalls). After half hour started again but only ran for about 10 minutes at about 1200 rpm (wouldn't restart). After another half hour started again, ran for about two hours at 1000rpm (then I shut off as we were back. (We went on a trip, about 25 miles each way, this was the return home, didn't try to increase speed during those two hours, preferred to get as far as possible with two engines rather than risk losing one even though at slow speed).
Next day: started, ran about 15 minutes at 2900rpm, then started to quit. Switched hoses. Problem stayed with same motor so not filter (at least main one, there is a smaller one mounted to engine, replaced earlier but only first time). Have only been using one tank so both engines getting gas from same tank. Other engine running fine so fuel itself not problem.
Seems to be getting better in that it will sometimes go longer if speed kept low, but still won't go for extended period at cruising speed.
I put electric fuel pump in gas line (between filters) as a way to test if fuel pump (mechanical) was bad (although wouldn’t mechanical fuel pump be good or bad, not work for a while then need to rest?). Figured it would also pull gas through filter if it was partially clogged. Does not seem to make any difference.
I was going to try to test fuel flow at carb but don't have a way to do that without it going all over (hot) engine. Is there a gizmo that can be put at the end of the fuel line at the carp to measure gas pressure or flow? I did back the fitting off, gas came out, seemed to be under pressure which suggests no problem with the pump.
Only thing that makes any sense to me is clogged filter, but hose switch seems to eliminate that. (plus multiple new filters, which should still be clean since using other gas tank.) I don't know of anything else that affects a motor during use (other than sometimes a coil, but replaced that already). Any suggestions appreciated.
.