evidrude xp150 high speed miss

[hardtime]

1990 evidrude 150 that starts fine,idles fine, runs up to 4500rpms fine, from 5000-5500rpms<br /> it starts to miss or skip some times bad. go back to 4500 it does ok. carbs. rebuild last spring,<br /> replaced fuel lines from tanks,to motor. the rectifier was also replace. did fine water leak at<br /> exhaust cover plate,replaced gaskets. replaced plugs .checked wires. set plugs at .035 the <br /> book call for .030. ran marine carb. clearer, is next step to coils and power pack?

 

[12Footer]

Re: evidrude xp150 high speed miss

Hardtime, welcome to iboats...So far,so good.<br />You haven't wasted any effort,as those areas are all suspect. Now procede. Check the magnets in the flywheel,as they are famous for comming loose.If you remove the flywheel,and find an area that appears to be unpainted,as if it were masked-off,the high-speed magnet has left.<br />It could also be the trigger. I would almost gaurantee the CD box is ok, because it does fire at lower speeds. And they have two scources for pulsing the pack at lower and higher RPM's<br />I've never found this to be the case,but I read about it here on iboats often. In my own travels, I have found a warped key in the flywheel keyway ,and I've found a sloppy ball-and socket connection in the timing advance linkage..(so check your timing throughout the power band).<br />And I have had a Merc with a coil breaking-down at higher RPM. The spark was arching-across it to the frame.This is best found on a dark night,while observing the engine for visable arching...It could even be a plug wire arching,so it's easy to find this way.<br />Also chack for proper engine cooling, as some engines are designed to not let you run WOT when it is running too hot.

 

[almost retired again]

Re: evidrude xp150 high speed miss

Howdy Hardtimes,<br />I belive that your engine is equipted with rev. limiter packs,it could be that a pack is kicking in the rev. limiter too soon.

 

[hardtime]

Re: evidrude xp150 high speed miss

Thanks 12 Footer for the info.<br /> i ran it wed. nite looking for a storm and did not see one! i even replaced two plug wires<br /> that did not look right to me. so i"ll let you know what i find under the flywheel.<br /> also when i check the plugs they are dry not oily this lean is it?

 

[hardtime]

Re: evidrude xp150 high speed miss

Hi almost retired Thanks<br /> i have look at wire diagrams they do not show a limiter pack. i hame a 35amp system.<br /> where mite it be?