Tweet
I have had this 17.5 Ft. 1966 Gl***par Flying V with a 1969 115 HP outboard for a few years. It runs pretty well for its age and I believe it has fairly low hours. I am an auto mechanic and have been trying to resolve this one issue for a while. When I am throttling up, it hits a point and starts slowing RPMs instead of increasing. This is before the throttle reaches fully open. I have replaced the reeds with CCM fibergl*** reeds and rebuilt the carburetors most recently without any effect. I replaced 2 of the high speed fuel jets, but they all looked like new. I replaced the impeller last year. The vacuum hose to the fuel pump seems a little loose, but I don't think that could be the problem. The fuel pump is strong enough to suck a plastic fuel tank almost inside out when I forget to open the vent. I have tried adjusting the timing, but it seems to make no difference. Also, my top speed is 32 MPH, does this seem about right? If anyone has any ideas as to what else I could try, I would be very appreciative.
-
-
Get some help and use a timing light to check that each cylinder has steady fire and check timing at wide open throttle. -
Spark is good on all cylinders and the engine runs smooth at high rpm, just doesn't seem to reach its potential rpm. I pulled all plugs and grounded spark wires, opened throttle all the way and set timing with timing light while cranking with starter.Comment
-
Check to see if throttle plates in carbs are opening all the way when at full throttle, when that engine was built we had leaded gas not something that came out of a corn field so might try a higher octane or some non-ethanol gas.Comment
-
I did find that the upper and lower throttle plates weren't timed properly, and the throttle was going beyond wide open. I made some adjustments and it seems better. I still think I should get a few hundred more RPMs. I am getting 4100. I think I should get 4500. I've tried non-ethanol 91 octane before with no noticeable effect.Comment
-
I also have a gl***par boat. Mine is a 1965 gl***par Avalon with a 1991 Johnson 70 hp motor.
My top speed at wot is 32mph at 6,000 feet above sea level. I think you are not getting all the power that engine should deliver.
I just bought a 2017 etec 65 hp to repower my boat, I'll have it in the water in May for speed trials.
I did switch props last year and added 2 mile plus at wot, but it lowered rpm's by 400.
Hope you resolve the problems
Comment
Comment