Captain Kokanee
Recruit
- Joined
- Jul 12, 2013
- Messages
- 4
Hi guys,
Last year when on the lake I noticed dramatic drop in power on our C75 when under heavy load (pulling a tube) and it just couldn?t get onto plane. We have a very light fiberglass boat and without load it would be on plane in seconds and run perfect at WOT. Unfortunately because of work and college I am just approaching the problem now two weeks before our annual weeklong family reunion on the lake. We bought the boat 8 years ago but I will say overall the engine looks to be in immaculate condition.
To identify which of the three cylinders were causing problems we pulled the spark plug caps while the engine was running one by one. The motor began to stumble when either the top or bottoms caps were pulled, middle=no change.
quick compression test =good
sparkplugs/spark=identical and fine
basic fuel filter=small build up of small black particles, possibly from fuel lines (a tank of 90/10 gas overwintered in it 3 years ago)
fuel- new, ethanol free and run with yamaha ringfree as usual
Am I correct in assuming it has a clogged jet? If the particles on the fuel filter are degraded rubber, the same type of lines are past the filter which is not good. I read through pretty much every thread for carbs on iboats and this seems to be the likely problem. Also do I need to clean all carbs since it may be the idle jet clogged on one and the main on another?
Thank you so much for any and all help and sorry for the long post
Last year when on the lake I noticed dramatic drop in power on our C75 when under heavy load (pulling a tube) and it just couldn?t get onto plane. We have a very light fiberglass boat and without load it would be on plane in seconds and run perfect at WOT. Unfortunately because of work and college I am just approaching the problem now two weeks before our annual weeklong family reunion on the lake. We bought the boat 8 years ago but I will say overall the engine looks to be in immaculate condition.
To identify which of the three cylinders were causing problems we pulled the spark plug caps while the engine was running one by one. The motor began to stumble when either the top or bottoms caps were pulled, middle=no change.
quick compression test =good
sparkplugs/spark=identical and fine
basic fuel filter=small build up of small black particles, possibly from fuel lines (a tank of 90/10 gas overwintered in it 3 years ago)
fuel- new, ethanol free and run with yamaha ringfree as usual
Am I correct in assuming it has a clogged jet? If the particles on the fuel filter are degraded rubber, the same type of lines are past the filter which is not good. I read through pretty much every thread for carbs on iboats and this seems to be the likely problem. Also do I need to clean all carbs since it may be the idle jet clogged on one and the main on another?
Thank you so much for any and all help and sorry for the long post