no spray

Divnnc

Recruit
Joined
Oct 4, 2004
Messages
5
This past weekend, I put the boat in the water and when I started the starboard motor, I noticed a spray of fuel hitting the water behind the boat. Someone suggested bad fuel pump. I pulled all three off, and noticed that one had a tear in the diaphragm. Just to be sure, I replaced all three pumps with new ones. <br /><br />Started the engine again, and the fuel spray was still there, but no where near as bad. There happened to be an outboard mechanic near by and he offered to look at it for me. We took the carburetor silencer covers off and ran the boat. The engine started fine, idled fine, and ran, ok. But the port bank of carbs was not spraying fuel from the high speed jets in the mid-range, not till we were above about 3000-3500 did they spray like the starboard bank. He suggested that I rebuild the carbs, which I did.<br /><br />Slapped the rebuilt carbs on the engine and fired her up. No fuel coming out of the exhaust! After about 10 minutes of adjusting she was idling at 700 and all seemed good. I took it out for a high-speed test, and the port bank was still not spraying like the starboard side. Once the engine is above 3k they all spray about the same, but the port bank middle carb doesn’t spray as much as the others, and I can’t seem to get it figured out.<br /> Now here is the kicker! When I put my hand in front of the other carbs, there is a definite suction, but the one that won’t spray doesn’t draw much air at all.<br /><br />Any suggestions? I have not done a compression test, that is next on the list.<br /><br />Thanks in advance.<br /><br />Matt-
 

jim dozier

Lieutenant Commander
Joined
Jan 8, 2003
Messages
1,970
Re: no spray

From your description you aren't developing a proper vacuum in the crankcase of the port bank middle carb. Compression test is definitely in order. Bad piston or rings or crankcase seal or reeds. Probably the piston and rings are gone.
 
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