VE8EV
Petty Officer 2nd Class
- Joined
- Sep 5, 2012
- Messages
- 109
Still struggling with the getting the engine running properly. The problem is it doesn't seem to have any top end power and won't go past 2100 RPM. I've read the "low WOT" stickies and the carb troubleshooting page from the service manual but I'm hoping to narrow the cause down before I put it in the water again.
Here's what I believe is NOT the problem:
1) Prop is the same one it's always had with no previous issues.
2) Tune-up was just done and dwell/timing was double-checked. Had the same issue before the tune-up.
3) Gas is good, drained all the old stuff before I ran it and have put at least 50 gallons through it so far.
4) Fuel filter element has been changed twice (looked clean both times, no water either)
5) Flame arrestor is clean
6) Inspected the entire exhaust system, no restrictions (no flappers either, never had them)
7) Throttle linkage is OK, last few inches of lever travel are just "dead", no change in engine pitch.
Clues:
1) The engine purrs like a kitten. No misfires, no roughness, no hesitation, no surging, just won't go over 2100 rpm.
2) I rebuilt the carb and very carefully matched all the new gaskets to the old ones. Set the float bowl levels, both bowls (4 bbl Holley 4160) have gas in them.
3) After the tune-up didn't fix the problem I pulled the carb off and double checked all the gaskets (I had kept all the old ones) and checked all the orfices in the secondary metering plate. Everything looked good but I remembered that it had originally used an open throat gasket under the carb even though the manifold was a four-holer. I had put a four-hole gasket on after the rebuilt so I took it out and replaced it with a new open throat one. When I put it in the water for a test run afterwards it was good! Blew right past 2100 rpm and seemed to have lots of throttle left when it hit 3000 rpm but the water was too rough to open it right up. I though I had it beat but the next time out (yesterday, on calm water) it still hung up at 2100 rpm.
4) I visually confirmed that the secondaries are opening but can't tell if they are opening far enough.
5) No gas in the sight bowl on the fuel pump.
Clue #1 and #3 are the ones that have me stumped. I don't think it was just the rough water helping to get it on plane that day as it also seemed to have the good old "get up and go" again but it has been 22 years since I drove it so not 100% sure.
So, any comments on which of the potential causes of low WOT would manifest themselves with a smooth running engine and fit with the other clues?
Thanks in advance to the experts here, this site is almost as good as actually being on the water!
Here's what I believe is NOT the problem:
1) Prop is the same one it's always had with no previous issues.
2) Tune-up was just done and dwell/timing was double-checked. Had the same issue before the tune-up.
3) Gas is good, drained all the old stuff before I ran it and have put at least 50 gallons through it so far.
4) Fuel filter element has been changed twice (looked clean both times, no water either)
5) Flame arrestor is clean
6) Inspected the entire exhaust system, no restrictions (no flappers either, never had them)
7) Throttle linkage is OK, last few inches of lever travel are just "dead", no change in engine pitch.
Clues:
1) The engine purrs like a kitten. No misfires, no roughness, no hesitation, no surging, just won't go over 2100 rpm.
2) I rebuilt the carb and very carefully matched all the new gaskets to the old ones. Set the float bowl levels, both bowls (4 bbl Holley 4160) have gas in them.
3) After the tune-up didn't fix the problem I pulled the carb off and double checked all the gaskets (I had kept all the old ones) and checked all the orfices in the secondary metering plate. Everything looked good but I remembered that it had originally used an open throat gasket under the carb even though the manifold was a four-holer. I had put a four-hole gasket on after the rebuilt so I took it out and replaced it with a new open throat one. When I put it in the water for a test run afterwards it was good! Blew right past 2100 rpm and seemed to have lots of throttle left when it hit 3000 rpm but the water was too rough to open it right up. I though I had it beat but the next time out (yesterday, on calm water) it still hung up at 2100 rpm.
4) I visually confirmed that the secondaries are opening but can't tell if they are opening far enough.
5) No gas in the sight bowl on the fuel pump.
Clue #1 and #3 are the ones that have me stumped. I don't think it was just the rough water helping to get it on plane that day as it also seemed to have the good old "get up and go" again but it has been 22 years since I drove it so not 100% sure.
So, any comments on which of the potential causes of low WOT would manifest themselves with a smooth running engine and fit with the other clues?
Thanks in advance to the experts here, this site is almost as good as actually being on the water!
