140hp crossflow wont rev, ready to go black

[fast_c_class]

crossflow v4 wont rev <br /><br />--------------------------------------------------------------------------------<br /><br />engine is a 140hp, last year it would run 6200 rpm all day, this year it i cant get it to rev over 5000rpm. nothing has changed since last year.<br />ive tried rebuilding the carbs, fuel pump, new gas, new fuel lines, new plugs.<br /><br />and to top things off now my livorsi tach stuck at 5000 (key on or off it wont go back to 0) and it will move alittle if you rev the motor and stay in that new position????<br /><br />Am i barking up the wrong tree? is this really a fuel problem? or does it sound like an ignition problem?

 

[walleyehed]

Re: 140hp crossflow wont rev, ready to go black

What year model is it?

 

[fast_c_class]

Re: 140hp crossflow wont rev, ready to go black

1984 140hp crossflow v4

 

[fast_c_class]

Re: 140hp crossflow wont rev, ready to go black

btw the tach is definetly fryed, and its only 1 year old, a good one too... Livorsi

 

[BoatBuoy]

Re: 140hp crossflow wont rev, ready to go black

You said that it tached 6200 last year, but only 5000 this year, and then said your tach was stuck at 5000, then said it was fried. Is your problem the motor or the tach?

 

[walleyehed]

Re: 140hp crossflow wont rev, ready to go black

OK, wanted to make sure we didn't have an '85-'86 140hp which is a looper...<br />As BB said, are you sure we don't have a tach issue???<br />Is the boat performing any different??

 

[fast_c_class]

Re: 140hp crossflow wont rev, ready to go black

yes i should have stated that last year it would run 65mph gps and had a neck snapping holeshot, now it feels like i have 10 peaple in the boat when i try to get on plane and top speed is only 52mph. <br /><br />the tach was actually filled with smoke, i checked the wiring in the back thinking that something shorted, but everything was ok.<br /><br />i have tried several sets of carbs both of which i have recently rebuilt. i also put all new fuel lines from the carbs to the tank with new clamps. i rebuilt the fuel pump last week and cleaned the screen in it.<br /><br />all this is leading me to beleive i have some electrical problem, especially with the tach problem.

 

[fast_c_class]

Re: 140hp crossflow wont rev, ready to go black

ok i checked the spark today, and only one plug looked like it was firing good, the other 3 looked weak but sometimes one would flicker good. i decided to take the coils off and test them with the ohmmeter. this is what i got<br /><br />all coils measured in the 250-300 ohm range between the high tension wire and ignition wire. within spec<br /><br />all coils measured .3 ohms between the ground wire and the ignition wire..out of spec according to my manual<br /><br />questions..<br />1. what could cause the tach to go up in smoke like it did?? i fogged up with smoke not water vapor.<br />2.its unlikely the coil or powerpacks did the damage, so i guess im pointing my finger at a stator that is bad am i right?<br />3. if the stator is bad could it have damaged the powerpacks too?<br /><br />im afraid to put new coils on this thing if its just going to fry them again (remember my tach is already a crispy critter)

 

[walleyehed]

Re: 140hp crossflow wont rev, ready to go black

First, are you running a 23 pitch, or a 25???<br />Have you checked charging output at the battery with the engine running???<br />The stator check list is in the manual as well, and is very easy to test.<br />The Reg/rectifier may have issues causing the tach problem, but check the stator first.<br />Don't forget my first question on the prop....I'm curious about that.

 

[fast_c_class]

Re: 140hp crossflow wont rev, ready to go black

ive tried my 22,23, and 24 pitch props this year all of which yielded similar results. only the 24pitch is new, the 22 and 23 worked great last year.<br /><br />i guess i will be checking my stator tonight after work.