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DF 140 Surges at 3000 RPMs

acdiii

New member
"Recently bought first boat, 2

"Recently bought first boat, 2002 Cape Horn 19 with a DF 140 Suzuki. Motor cranks great and runs smooth until reaching @3000 RPMs then engine labors but will not run any higher than 3000 RPMs, once throttle is reduced then engine smooths out. I have changed to aux fuel tank but no change. Pee stream from the engine is weak. Engine has 500 hours. Any recommendations? Thanks"
 
Any warning lights? Have you t

Any warning lights? Have you tried anything like squeezeing the primer bulb to see if it picks up RPM.
 
"No warning lights, did not tr

"No warning lights, did not try squeezing the primer bulb....did the same for internal and aux fuel tanks."
 
"squeezed bulb while engine wa

"squeezed bulb while engine was laboring at 3000 RPM, no change. May be time for a Suzuki Doctor visit...thanks for your help.
ACDIII"
 
Is this problem happening whil

Is this problem happening while in gear or in neutral.
 
In neutral the engine has a re

In neutral the engine has a rev limit protector. If the problem is identical in gear you could have a bad neutral switch at the engine. The engine thinks it is still in neutral when you go fwd. You would have to chk to make sure it is working with a meter or SDS. The Suzuki Doctor should have SDS.

I know this sounds silly but you may want to try new spark plugs. I have fixed more than one fourstroke with new plugs. They will foul plugs just like a two stroke.
 
"Thanks again for your help Ro

"Thanks again for your help Robert...I've delivered to the marine repair guy, I do remember now that during the sea trail the boat came up to almost 5000 RPM once and immediately went back to the 3000 RPM range which made us believe we had a bad fuel issue....I did change 3 of the 4 plugs and could not get to the fourth without taking engine cowilng/cover off (beyond my expertise). so maybe the hard to get to plug is the problem. The Suzuki repair center is D & P Marine in Austell GA, hope they are good."
 
Robert
The problem was the ne


Robert
The problem was the neutral safety switch...thanks again for your assistance

ACDIII
 
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