Ive got an older ski boat 1976 stinger with a 4 cylinder volvo penta motor?

Question

it runs fine for the first run around the lake but as soon as it warms up , all of a suddon when i go to give it some gas at about 3500 rpms it falls flat, it will idol fine like nothing is wrong but if i give it gas it bogs, anyone?

Answer 1

its probably the accelerator pump in the carburetor- if its a 4 barrel or dual stage 2 barrel carb, it may be a plugged secondary jet- either way, the carb is the culprit-

Answer 2

Generally when an engine fails after a warm up the cause will be electrical.Insure that all plugs are firing.You may need to replace the wires and spark plugs,don't be shy,do a complete tune up.