Posted: 6/8/2009 2:31:50 PM EDT
| not sure if this topic has been covered here but this is really bothering me. I've had this boat for 3 seasons and have used Sunoco 89 octane which contains up to 10% ethanol. There is a warning sticker next to the fuel tank to not add any alcohol based fuel additives. Well, here in NY that's damn near impossible and beginning next year all stations will be using ethanol. Is there a solution out there? The motor is a 1987 GM 4.3 v6. |
|
Alcohol in the fuel will harden and deteriorate the rubber fuel lines and some plastics used in the fuel system. If the boat has a fiberglass fuel tank (which it prolly does not) it will leach the resin from the glass and cause major trouble. Being a 1987 boat, it would be prudent to change all the rubber hoses in the fuel system like the filler hose and vent line as well as the lines that come from the tank to the fuel pump. This will remedy the problem. Just remember that the 4.3l engines will live longer using premium fuel, 89 or up octane. These engines have a tendancy to run lean on the front cylinders and will detonate causing valve "tuliping" and or blown head gaskets. In extreme cases it will melt a hole in the piston dome. Using premium fuel will minimize the detonation issue as will having the timing looked at to make sure it isn't advanced too far.
On another subject, when was the last time the impeller was changed? ETA–– What brand? OMC,Mercruiser, Volvo? |
|
The impeller should be changed anually. It is a rubber "paddlewheel" looking device that pumps lake/sea water to the engine for cooling. If it goes away, the motor will overheat in short order. Then the hunt is on to find the shredded impeller pieces so they won't restrict the flow of cooling water.
Replacing the fuel hoses with new alcohol approved hoses should cure your problem and help you sleep at night. One other thing that alcohol may affect is the fuel pump. It has a rubber diaphragm inside which may also be affected by the alcohol. 
|
The impeller is easy to change on the Cobra drive. It is located under the rear cover. 3 bolts hold on the rear cover to expose the impeller housing. You will prolly just need the impeller and o-ring. Inspect the liner and wear plate for deep grooves, replace as needed. Carry the tools and a spare in the boat for field repairs.
|