evinrude xp 150 '89

[michelobwm]

i have an '89 evinrude xp150 on a 17' nitro bass boat. the engine has never idled well from day one often shutting off when going from reverse to forward or the other way. i've learned to accept that but still curious as to why. also it has developed a mid range "miss" (about 3000 to 3100 rpms). it has never turned more than 5100 rpms and now only seems to turn about 4800.I have had the carbs rebuilt a couple of times with no improvement. I frequently run omc tuner thru the carbs, have tried the seafoam product and omc carbon gaurd. any advice on how to cure these two problems would be appreciated

 

[Reel Appeal]

Re: evinrude xp 150 '89

Is the motor hard to start or not?

 

[Hooty]

Re: evinrude xp 150 '89

You probably know, the engine should idle about 650rpm in forward gear. That may be just take adjusting. If the carbs have been removed, rebuilt and re-installed without a snyc & link, that's where I'd start.<br /><br />c/6<br /><br />Hooty

 

[afrifle]

Re: evinrude xp 150 '89

Sorry this is long...<br />I also have an xp150 (1990) on a 175TF Nitro (1990). I was having trouble with the idle not being reliable, especially long periods of idle like when entering the marina and loading. I lurked here for a while listening and following the problem matrix in my manual. Here are the things I did to check and cure my motor:<br /><br />1. Check for a good primer bulb and tight seals on all fuel lines. Sucking air is bad.<br />2. Compression check. I have 87 psi on all 6, before and after decarb treatment.<br />3. Sync and link by the book.<br />4. Idle timing check and adjust.<br />5. Idle speed adjust.<br />6. Clean fuel filter. I now use one of the clear ones that I can see through and easily replace. I had junk in the bottom of my tank.<br />7. Here is one that was hard to figure out: After the decarb, I pulled all the recircualtion lines when the carbs were off. There was a lot of junk and goo in those lines, especially the bottom one. After cleaning them out, idle on the lake was smoother.<br /><br />I hope this helps you. Email if you want to talk about this boat/motor combo. I love my setup, I just wish this motor was a 175 to get this beast of a boat moving a little faster.<br /><br />Justin <br />afrifle@yahoo.com