forward lost power ,reverse fine

cjkerns

Cadet
Joined
Aug 1, 2002
Messages
21
evinrude 30hp told it was 90 model on 16 double jon.<br />I can turn the throttle wide open when I get it in the water and it only raises the front and will not take off. When in reverse it will turn wide open. Putting it in reverse and revving it seems to help get the eventual high speed forward. It'll run wide open for approx 1/8 mile before it goes back to slow crawl.If the throttle is let up at all it will slow before the approx 1/8. Once it goes fast the first time I can whack the throttle and get a response sometimes 2nd,3rd maybe 4th time. No middle throttle,slow or wide open is only choice. Seems to get the first burst of speed in wake,after high reverse,or when motor is tilted up and air bubbles are allowed to get around the prop. Low resistant times in other words.<br />Carb was taken off and cleaned.<br />New fuel line and bulb.<br />Flywheel removed ,magnets built in on this model.(LOCAL MECHANIC THOUGHT MAGNETS COULD HAVE FALLEN SO I TOKE IT OFF TO INVESTIGATE.)<br /><br />Stator didn't appear to be damaged to untrained eye.<br />Unplugged top coil from stator and it shut off<br />engine.<br />Unplugged bottom coil from stator and it kept running with no change in idle.<br />Also noticed spark plug wire on top got more volts than did the bottom.
 

Spidybot

Lieutenant Commander
Joined
Apr 4, 2002
Messages
1,734
Re: forward lost power ,reverse fine

Lots of facts mixed here.<br /><br />Have you checked for spun prop (when the prop hub turns correktly woth the spinning shaft but the prop itslef slips on the hub)?<br /><br />Try a search on this site for 'spun' as it has been discussed thoroughly before.
 

cjkerns

Cadet
Joined
Aug 1, 2002
Messages
21
Re: forward lost power ,reverse fine

Spun prop is definately not the problem! When the boat motor finally opens up it takes off on plain instantly but the engine speed will slow after a ways of wide open running then the boat starts to settle back in the water. then it will hit high rev want to plain, then hit sloww rev, slow hit high rev again, plain.<br />its runs like something with a short. slow,hit,slow,hit,slow, wide open a ways (distance varies),slow,hit,slow,wide open,etc....
 

Spidybot

Lieutenant Commander
Joined
Apr 4, 2002
Messages
1,734
Re: forward lost power ,reverse fine

Sounds as if your tank cap vent is not allowing air to replace the fuel used.<br /><br />Try running with the cap off for a while.
 

cjkerns

Cadet
Joined
Aug 1, 2002
Messages
21
Re: forward lost power ,reverse fine

I have three six gallon tanks and its the same on all three. Stator to me is in question. even though it looks fine I don't understand the big differences in its out put. :confused: the wire from stator to top piston can't be unplugged without it shutting engine off. the bottom piston wire from stator can be unplugged and the engine run as normal. ( this test done on land in neutral.) can plug wires from stator back up and check the volts at spark plug wires and the top cylinder has almost double the volts. wondering if this may be sign of future death of stator and maybe the cause of current problems.
 

sloopy

Commander
Joined
Jul 12, 2002
Messages
2,999
Re: forward lost power ,reverse fine

replace both spark plus, its only fiing half the time in the bottom cylander! get new wires too, ceck the gap, and ur goooood tooooo gooooooo!
 

cjkerns

Cadet
Joined
Aug 1, 2002
Messages
21
Re: forward lost power ,reverse fine

just went down and removed plugs.put plug in top plug wire and hit starter... very good fire. took same plug and wire and put it on the bottom cylinder terminal and got no fire at all from bottom terminal. something is completely wrong now.
 

cjkerns

Cadet
Joined
Aug 1, 2002
Messages
21
Re: forward lost power ,reverse fine

does this help narrow it down for anyone?
 

sloopy

Commander
Joined
Jul 12, 2002
Messages
2,999
Re: forward lost power ,reverse fine

yes replace both plus and wires, double check that the gap is right (1mm?) then check to see if you have a spark in the bottom cylander.
 

sloopy

Commander
Joined
Jul 12, 2002
Messages
2,999
Re: forward lost power ,reverse fine

replace both plugs and wires....
 

sloopy

Commander
Joined
Jul 12, 2002
Messages
2,999
Re: forward lost power ,reverse fine

also besure that the boots on the cables are snug and not dirty, is this an electric start?
 

sloopy

Commander
Joined
Jul 12, 2002
Messages
2,999
Re: forward lost power ,reverse fine

hi this is shoafin sailor again, you could also have an ignition problem!
 

cjkerns

Cadet
Joined
Aug 1, 2002
Messages
21
Re: forward lost power ,reverse fine

yes, it is electric start.<br />what i don't get is i can take a plug and plug <br />wire known to be good and it has excellent spark on the top terminal . Then take the SAME plug and plug wire and put it on the bottom terminal and not get a spark at all. all comments and ideas appreciated.
 

G DANE

Commander
Joined
Nov 24, 2001
Messages
2,476
Re: forward lost power ,reverse fine

Hi Cjkerns<br /><br />Im not familiar to the 90 model - i only know up to 1989. But till then every plug has ist own coil. If you have this setup too, it sounds like lower coil is bad. Try to check that.
 

cjkerns

Cadet
Joined
Aug 1, 2002
Messages
21
Re: forward lost power ,reverse fine

i think your right!!! exchanged the wires from the good coil to the bad or lower one still no spark with known good wires hooked to it. thanks to every one . gone to get plugs, wires and new coil. :) :) :) :)
 

cjkerns

Cadet
Joined
Aug 1, 2002
Messages
21
Re: forward lost power ,reverse fine

Just got back from waterway test and it runs better now than it ever has since i bought it. THANKS TO EVERYONE FOR THEIR INFO. <br /><br /> 1ST MATE BUT LEARNING<br /> CJ
 
Top