Re: 2006-2007- 115-hp e-tech, miss or stumble
They sell the Etecs as not having to have maintenance for 300 hrs, plugs included. They are different to the old Fichts that had multiple firing which would eat plugs in no time.
Checks you can make that may make a difference.
1. Make sure your fuel is fresh and has not water or contaminants.
2. Check the plugs. If the gap is over .030 it might be a good idea to change them. Although I have seen Etecs run well with huge gaps, especially at high speeds. Usually the gaps will make a difference at idle speeds.
3. Check your prop for damage. Nicks, bent or torn up from sand. That will cause the prop to loose efficiency. Does the engine vibrate at those speeds too? Would be a question to ask yourself if it does.
4. Take a compression check on the engine. Just to make sure it is mechanically sound.
5. If you have a gauge that will read vacuum, put it in line with the fuel supply and see if you have any restrictions. If you have one that reads pressure or both, hook it up on the supply side of the lift pump and see if you maintain pressure. 4 in vacuum and no more for the vacuum test. About 5 to 7 psi for the supply side.
6. If you have a guage that will read to about 60 psi with a fitting that will attach to the test fitting on the high pressure pump. put it on the engine and go for a run. You should have 20-30 psi constant. Any drops in pressure would be suspect, especially at high speed.
Short of these checks, you are really hard pressed if you don't have the computer software to monitor the engine. You have a lot of inputs that you can monitor and control of the injectors to play with to see if they are all doing their jobs correctly.
One other thing though, check the secondary wires for a small wire that comes from the shielding. It is a ground wire and is for electrical noise, if any are rotted through and not connected. Change them for new ones.