Just to eliminate ANY kind of obstruction issue I'd recommend:
Prerequisite - if your system still has the Perko ceramic filter in place, this should be drained, cleaned out, & CAREFULLY filled with clean fuel and screwed back into place.
1. disconnect fuel line at tank (anti-siphon valve remains with fuel line). Fit clear hose tightly over gas tank fitting. Try pulling fuel up and out of tank. Clear hose will let you:
- not get a mouthful,
- see if it's easy to pull fuel from tank ** no obstruction
- see (inside of hose <use a decent length to allow what is at bottom of tank to make it up into hose> if tank loaded with gunk at pick up tube's bottom>)
Everything good? Next step...
2. Disconnect anti-siphon valve from disconnected fuel line.
- check for orientation (not mounted backwards (if that's possible?) which would definitely prevent fuel getting from tank!)
Clear? Remount to tank (fuel line from tank still disconnected.) Connect hose used at fuel tank to this end of fuel line.
3. Disconnect fuel line from inlet side of fuel/water separator. Connect clear hose to this end as well.
Place end of clear hose at fuel tank line in clean/clear jar and secure so it won't come out of jar -OR- jar tip over. Blow into fuel/water separator end hose. You should get something coming out of fuel tank end hose. Since you cleaned the Perko filter earlier anything that's not clean fuel was in the fuel line.
If all the above are completed successfully,
(You can now reconnect fuel line back to inlet assembly on tank and inlet side of fuel/water separator)
You now have the following to check:
A. Fuel delivery from inlet side of fuel/water separator thru that filter to inlet side of fuel pump.
- the "blow" test from above can be used from outlet side of Perko filter to inlet side of pump - disconnect fuel line at Perko outlet (easier to get to and fit hose to), connect hose. Connect other hose to line at inlet fitting of fuel pump. Place hose end in jar and secure. Try blowing air at Perko end. You should be able to easily blow air thru line and see gas (gunk?) in jar.
Clean/clean? Next step...
B. Pull hose from Perko and reconnect fuel line at Perko and inlet side of fuel pump***
*** as mentioned earlier in posts, it might be that the arm of the fuel pump might have been installed such that the engine lobe that rotates against the arm is doing so incorrectly. Now, with the inlet side of fuel line disconnected, would be a good time to disconnect the outlet line, pull the fuel pump and see if the wear Mark's are where they should (pump arm rubbing against line in correct fashion). Didn't which engine is affected..
-> port? - easy to shine flashlight into pump arm hole in engine and see cam that fuel pump arm runs against.
** if you can't easily see cam, or you want to check that it's rotating, you can (after disconnecting center distributor wire so engine won't start) bump the engine to check cam's positioning.
-> starboard ->
tougher but doable using an 'in place' (ie. light with a clamp to allow hands free use) light and mirror (selfie stick type) if you can't maneuver over engine.
- after confirming pump placement correct, connect hose to outlet line of fuel pump. Disconnect line at carb, connect hose to this end. Perform the 'blow' process from fuel pump outlet side of the pump line to the carb.
... Ok? Then check the inlet port of the carb. There's a screen there that can be removed carefully and cleaned.
--> reconnect fuel lines at ALL connection points.
After performing (successfully?) all the above, you've eliminated 99% of obstruction possibilities. The remaining 1% could be at the carb itself in the ports of the carb. If not an obstruction, then a mechanical issue (fuel pump - such as Jeff mentions above) is just about the only remaining possibility.
PS - I tell you all of the above because I had to do it last year on the starboard engine. My issues resulted from having left the starboard fuel tank cap off, rain getting in the tank
. I tried pulling out the gunk (got about 2 gallons) but the damage to the fuel (ethanol gas - don't ask...
) had been done. Ended up giving away 60 gallons. Other issues turned out to be a bad fuel pump - tried installing an electric one <with a oil sending switch that is required), a momentary switch to prime and keep engine running till oil pressure activated the new switch throwing a relay that activated the electric pump normally. Had thought mechanical pumps for our engines were no longer available - WRONG! Andddd to top it off, the existing carb was so corroded from letting ethanol gas sit in it over a number of winters it couldn't be rebuilt so it had to be replaced. Major expensive lessons!!
Bill