Yamaha 250 tune up question

[bwarren]

I just bought a 1998 26 grady with a yamaha 250. I had the guy get the water pump changed and gear lube changed as well. the compression checked out fine. the motor has not been tune in at least the last 3 years and at slow sppeds seems to run a little rough. what should I have a mechanic do to the engine to optimize its condition?<br />thanks in advance

 

[John from Madison CT]

Re: Yamaha 250 tune up question

1. Replace low pressure fuel pumps.<br />2. Clean and inspect O2 sensor.<br />3. Clean/replace VST tank filter.<br />4. Clean inspect poppit valve.<br /><br />Otherwise, a competant Yamaha tech. should know what else to do.

 

[rodbolt]

Re: Yamaha 250 tune up question

if it went that long with no maint I would start with cleaning and testing the O2 sensor,cleaning the VST and injectors and testing the spark plug caps. also replace the remote oil tank filter and drain the water trap on the engine oil tank. its a good time to test the alarm when you drain the water trap.<br /> the maint schedule is in the marine tech guide, have your dealer make a copy for you.

 

[bernieb]

Re: Yamaha 250 tune up question

Be sure to buy a service manual,they're around 30 bucks but well worth it,you'll get most use out of it on the bathroom stand. But that engine is a good one, but requires maintenance so keep records on everything you do.Be sure you have a water/fuel separator in the boat and watch the red ring in the fuel filter under the hood,when the red ring rises you have water.You should start off with new 12v batteries .now for the technical know how learn to respect the names of Ray Nedec.and rodbolt and others of course.If you go offshore get the tow insurance not that you'll need it ,about 10 bucks a month.

 

[bernieb]

Re: Yamaha 250 tune up question

By the way that engine does shake at idle as it drops one cylinder, and drops another on the way up to getting on plane.