Yamaha 225, rough idle, stalls, surge

[jeuto]

Hi, I have a saltwater series 225, 2 stroke, we have put a number hours on it and it seems to run fine at higher rpms but I am having issues at low rpms and idle.<br />When you try to start it it stalls and runs rough until it warms up, even then then it still stalls. <br /><br />It also hesitates and then surges after you push the throttle forward, nothing happens and then by itself it starts to accelerate after a hesitation (maybe 5-10 secs). <br /><br />It will also stall when you bring it down from higher rpm to idle (a close call with a dock once). <br /><br />We put new plugs in it when we purchased the boat this year, the motor is a 1996, and it is fuel injected. It runs well at higher rpm.<br /><br />I appreciate your replies.

 

[31900]

Re: Yamaha 225, rough idle, stalls, surge

A model no and year will help.

 

[rodbolt]

Re: Yamaha 225, rough idle, stalls, surge

could be most anything but its a clasic symptom of one of your 3 low pressure fuel pumps is bad, the 225 EFI motor is a 3.1L. thats why we always like a model number, helps identify what yamaha it is. <br /> a low pressure pump diaphram failure can wipe out a piston, crankshaft or connecting rod or all 3. thats why its never advisable to run a two stroke when you know it has a problem, you can quickly turn a 40 dollar repair into a hole in the block.<br /> do you have a service manual? do you have any tools and a multimeter? if you wish to work on this motor yourself some tools and the manual will be required.

 

[jeuto]

Re: Yamaha 225, rough idle, stalls, surge

Yes we have a multimeter, tools and a SELOC manual. How would we test the pumps and what would we be looking for with out tools and multimeter? Should it be taken in and hooked up to a computer? Is that a last resort after we test the fuel pumps? <br />Thanks.

 

[jeuto]

Re: Yamaha 225, rough idle, stalls, surge

Adam1 the year is a 1996 and it is a 3.1L 6cyl, 225 with fuel injection.