MikeWhitney wrote:
If anyone is interested in the continuing saga...
I went out yesterday to do some fuel system testing to see if I could figure out why the boat isn't working well at WOT. Went out intentionally low on fuel (should have been about 5 gallons but I later remembered that I had pumped at least 2 out at home testing the fuel pump, so it was more like 3!) -- ended up running out of gas about 1/4 mile from the pumps I was on the way to. Added the one gallon of gas I had brought (just in case!!) but it turns out 1 gallon isn't enough when the boat's flat! Got a tow from a nice family passing by, fuel up, and ... spent the rest of the day trying to get the boat to start. Starting fluid, gas poured down the carb, full thottle, part throttle ... nothing at all would get it to start. Spark was good.
Now I should mention that it has been starting harder and harder since I bought it. My fuel tests have mostly ruled out delivery problems -- 7psi, no air bubbles, etc -- so it's on to the carb.
After another tow back to the docks (I just got repaid the 2 tows I gave other people) and back at home this morning, it started (of course) perfectly fine. I was assuming that the engine wasn't getting any fuel, but now I have to believe that the engine was flooding. The weird thing is that the plugs were not fuel soaked at the lake. So it's a theory.
Spent most of the day learning everything I can about Holley carbs. Now there shouldn't be any problems with it, since the previous owner had just spent $800 having it rebuild along with some other stuff.
Well guess what? The mechanic was an idiot.
Problem #1 -- The accelerator pump outlet was turned 90 sideways and pushing all the fuel into one barrel.
Problem #2 -- the linkage on the choke was installed incorrectly. There is a little plastic tab which rotates on the choke shaft, with a little brass insert in the end to keep it down. This is supposed to be the weight which keeps the choke open to the coil-set limit (instead of a spring). The choke lever is supposed to be under this (weight pushing down), but it was on top so the weight was actually limiting how far the choke could open. So it was maybe going to 2/3 or 3/4 open.
Problem #3 -- Carb had the wrong power valve -- 4.5 instead of factory 2.5. Probably doesn't matter for the starting issue since it's only supposed to open in the absence of vacuum at WOT. So the 2.5 won't open until closer to full throttle ... which could help explain the WOT issues I have been having. Luckily the previous owner gave me the old valve, which looks like it's working fine (not blown or leaking) so I put it back in.
Problem #4 -- The power valve had *two* gaskets under it and one of them was torn. I figured out that the engine was getting flooded whenever the pump was on because I took the carb off, attached the fuel line, jumpered the fuel pump on, and held the carb horizontal over my head. Fuel started dripping out of the power valve port between the barrels on the bottom of the carb.
So I'm nearly convinced now that my hard starting, excessive fuel consumption, and rich running must have been due to this basically partially-open power valve at all rpms due to the tear. Probably worst at idle and startup when vacuum is high.
It runs *so* much better in the driveway after fixing these 4 problems -- I can't wait to get it out and see if I possibly fixed the WOT problems too...
Blah, blah, blah. When are you going to invite the whole club out water skiing?
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$27 for a new one, already on order.
