Rapid background: bought boat last year. cleaned/rebuilt carbs, new plugs, changed gear oil and ran her. Worked great. Over winter tore it down more and replaced electronics, new recirculating hoses, fuel lines, and lower seals.
First day out, ran great. 4500RPMS at WOT. Ordered a new prop to adjust the peak RPMS to the recommended 5k. Went out second time, WOT only got me to 3,000 RPMS. After about 30 seconds it finally kicked up to 4,500 RPMS. Got to where we were going and shut down. Rest of that day tho and every test since I have not been able to get back above 4,000 RPMS.
Replaced spark plugs, spark plug wires, verified Link&Sync, good constant spark on each wire using timing light, rotated in a known good power pack, ignition coals are good per ohms test (i dont have an extra one to rotate thru), replaced thermostats. Ran 4 gallons of 93 octane with 9oz of seafoam added. I always use a mix of 50:1 Evinrude synthetic oil.
Today rented a compression tester. As i pulled each plug i noticed this: Cylinders 1 & 2 plugs had a lot of carbon on them for only probably 2 hours of run time, Cylinder 4 plug some carbon, cylinder 3 plug was clean. Compression test showed 100 PSI on all 4 cylinders. Thoughts on these findings?
My next focus is the carbs for a potential issue with high speed jets. Anything else I maybe overlooking?
First day out, ran great. 4500RPMS at WOT. Ordered a new prop to adjust the peak RPMS to the recommended 5k. Went out second time, WOT only got me to 3,000 RPMS. After about 30 seconds it finally kicked up to 4,500 RPMS. Got to where we were going and shut down. Rest of that day tho and every test since I have not been able to get back above 4,000 RPMS.
Replaced spark plugs, spark plug wires, verified Link&Sync, good constant spark on each wire using timing light, rotated in a known good power pack, ignition coals are good per ohms test (i dont have an extra one to rotate thru), replaced thermostats. Ran 4 gallons of 93 octane with 9oz of seafoam added. I always use a mix of 50:1 Evinrude synthetic oil.
Today rented a compression tester. As i pulled each plug i noticed this: Cylinders 1 & 2 plugs had a lot of carbon on them for only probably 2 hours of run time, Cylinder 4 plug some carbon, cylinder 3 plug was clean. Compression test showed 100 PSI on all 4 cylinders. Thoughts on these findings?
My next focus is the carbs for a potential issue with high speed jets. Anything else I maybe overlooking?
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