Fuel delivery issue?

Nomo

Cadet
Joined
Mar 25, 2010
Messages
25
Happy Independence Day!
Looking for help on a ‘08 4.3TKS. Normally I have no issues getting right up on plane. Yesterday I would give full throttle on the lever but rpms wouldn’t come up as normal and couldn’t reach plane. After a few minutes of cruising with a steep bow angle all of a sudden rpms kicked in like a switch and immediately planes out. Then the boat would level for a few minutes at full speed and the rpms would begin to decrease until I lost plane and returned to a steep bow angle again. This cycle would repeat itself like clockwork all the way back to the boat ramp. I dumped my fuel filter and couldn’t see any water, but I’m not ruling out bad gas. Question I have is, does it seem like a weak fuel pump would be struggling to supply the carb? I have no running issues at low idle.
Thanks for your input.
 

alldodge

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Mar 8, 2009
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42,608
does it seem like a weak fuel pump would be struggling to supply the carb?

Yes I would look there first.
Antisiphon valve on top the fuel tank

Then measure fuel pressure, should be 3-7 psi from idle to WOT

If pressure is good, the might need to get into the carb
 

Nomo

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Mar 25, 2010
Messages
25
alldodge-
Thanks for the comment. Will throw a gauge on ‘er and see.
 

Nomo

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Joined
Mar 25, 2010
Messages
25
Fuel pressure reading was a steady 8psi for several minutes through a range of rpms. My original fuel tank is a 1986 vintage. I do not see an anti siphon valve.

Took the screen out of the carb and it didn’t have anything obstructing it that I could see.

Distributor cap looks pretty bad with what looks like corrosion or ash built up on the contacts. I cannot get the rotor off to inspect any further there. Is that just a friction fit or are there screws from under the steel plate?
 

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alldodge

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Hope the cap fixes the issue, but if it doesn't then may need a carb rebuild
 
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