1990 25hp Evinrude low idle ?

[Firstboat23]

ok some of you are familiar with my issues. I have taken my boat out twice. runs very fast with my 14 foot jhon boat great for fishing sounds like a champ at high idle and full throttel, in slow/no wake areas when I idle down there seems to be a hesitaion in the low idle. today I was showing my brother in law the weeki watchi river on gulf coast of fl and it back fired puff and blew my primer solinoide lever right out of its hole would not start back up I found that out after removing hood went like that for a minuit till I could figure out how to get er running again. this only happens when it is going slow, the motor idles down significantly when I put it in gear I just replaced old sparks plugs after getting it home after a broken trailer axle well anyway, i messes with slow idle adjustment and the idle bolt below the gear(which im going to set back the 1/4 turn) which made the idle a littel too high with same issue made the moter bang (not badly but enough to notice ) when i put it into gear is there another adjustment for my idle or any thoughts just dose not sound right to me at low idle?

motor e25eese

 

[tashasdaddy]

Re: 1990 25hp Evinrude low idle ?

well it sounds like you need a carb cleaning and rebuild kit. also may have shear the flywheel woodruff key. throwing the motor out of time.

http://forums.iboats.com/showthread.php?t=244013
(Carburetor Adjustment - Single S/S Adjustable Needle Valve)
(J. Reeves)

Initial setting is: Slow speed = seat gently, then open 1-1/2 turns.

Start engine and set the rpms to where it just stays running. In segments of 1/8 turns, start to turn the S/S needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running.

Eventually you'll hit the point where the engine wants to die out or it will spit back (sounds like a mild backfire). At that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting.

Note: As a final double check setting of the slow speed valve(s), if the engine has more than one carburetor, do not attempt to gradually adjust all of the valves/carburetors at the same time. Do one at a time until you hit the above response (die out or spit back), then go on to the next valve/carburetor. It may be necessary to back out "all" of the slow speed adjustable needle valves 1/8 turn before doing this final adjustment due to the fact that one of the valves might be initially set ever so slightly lean.

When you have finished the above adjustment, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.
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[Firstboat23]

Re: 1990 25hp Evinrude low idle ?

ok followed instuctions that you gave me was very close to what i was doing, checked woodruff key is in mint condition and everything lines up carb checks out ok, new plugs in starting to build up carbon after about 2 hours ao running engine . seafoamed deep creep into engine to get carbon build up out worked excellent ... went and adjusted idle again wen to good spot idle finde kicked it into gear and at low just a tad more throttle it was doing it again.... brrrrrrrrrrrr...chug chug brrrrrrrrchug chug chug brrrrrrrrrrrrrrrrrrrrrrrrrrchug chug pfft brrrrrrrrrrrr and so on to say the least there is a slight knock when it dose it and the backfire ing has all but stoped. i checked wires for possible arching every where seems to be ok im so stumped otherwise it runs great i just dont want to damage antything and get stuck out in the gulf of mexico. oh one more piece of info aon spark plugs checking them periodically took top out was wet (in a good way )
minor carbon build up took out botton was dry and a little bit burnt looking than the other..... not much just a little ....

 

[tashasdaddy]

Re: 1990 25hp Evinrude low idle ?

sounds like it is running on one cylinder. check spark with a spark checker.

also join us. http://forums.iboats.com/showthread.php?t=291501

 

[Firstboat23]

Re: 1990 25hp Evinrude low idle ?

spark is good enough a little small for my liking but is blue and about 3/4 inch long, im going to check magnito for rust ect in conections. compressinon is excelent 90-95 dry 100-105 wet no more than 5 lbs per square inch difference cylinder are the same. next step is romoving flywheel :redface:

 

[wbeaton]

Re: 1990 25hp Evinrude low idle ?

there is a slight knock when it dose it and the backfire ing has all but stoped.

Still sounds lean to me. When you say the carb checks out do you mean to say that its been rebuilt? Just because the engine responds to throttle and idle jet adjustment doesn't mean its functioning properly.

Is your carb in sync with the armature? Does it chug only at low idle?

How did you check the woodruff key without removing the flywheel?

 

[Firstboat23]

Re: 1990 25hp Evinrude low idle ?

yea it has been only at low idle I took eveything apart today and found everything good checks out i have rebuilt carb twice already i can take it off again it is very simple not like a car carb. i may have missed somthing but i ran coper wire all through it and jett looks good on visual inspection. armature is that involved in a linc n sync ? that might be the problem could you elaborate some more on that please

 

[Firstboat23]

Re: 1990 25hp Evinrude low idle ?

took the nut off and looked down the channel with my experience with lanwmower engins you can see if there was somthing up with the woodrif key, i got my gearpuller later tonight and took the flywheel off and the key is good there was a little bit of rust on the magnets not severe and on the back of the power pack cleaned it all off everything looks good put a light coat of wd-40 to prevent more rust from forming. light emerycloth ed all rust off, not i messed with the carb again and it sounds worse now but the spark has doubled is excelent now. my dad told me to get rid of the crappy champion sprk plugs and go with NGK plugs. i will adjust carb better tomorrow or friday again. but again help me out with armature

 

[Firstboat23]

Re: 1990 25hp Evinrude low idle ?

and it has been slightly higher than low idle low idle seems ok but if i bump it up a little medium rpm is the spot.

 

[Firstboat23]

Re: 1990 25hp Evinrude low idle ?

i just notice i was missing the roller for the cam follower could that be a problem?

 

[Mas]

Re: 1990 25hp Evinrude low idle ?

In my OEM manual for a '94 25 HP 'rude, it states the initial idle needle is 2 1/2 turns out from lightly seated...I'm wondering if it is the same for the '90.

For my '94 20 HP the OEM manual states 3 turns out from seated. I know that 1 1/2 out from seated is a good general rule, but different models might need a different starting point to get us in the right ballpark faster. Certainly, not having the roller is a problem, and likely is your problem, but it does sound like a lean problem. But either missing roller or incorrect idle screw will cause a lean issue!

Here is a link to my OEM page for a '94 25HP:

http://i129.photobucket.com/albums/p219/mas421/sc000a1f4a.jpg

Check it out,

MAS

 

[Firstboat23]

Re: 1990 25hp Evinrude low idle ?

looks like the exact same carb on my 1990 that is about where it like to start at too at 2.5 turns out ty for the link i whish that they would make manuals available online like kias website

 

[tx1961whaler]

Re: 1990 25hp Evinrude low idle ?

i just notice i was missing the roller for the cam follower could that be a problem?

Yes.

 

[Mas]

Re: 1990 25hp Evinrude low idle ?

looks like the exact same carb on my 1990 that is about where it like to start at too at 2.5 turns out ty for the link i whish that they would make manuals available online like kias website

Fix the roller first.

If that didn't fix the problem, then back out the needle another 1/8 turn and see if that helps. If that fixes the issue, back it out another 1/8 to prevent a lean condition.

Yes, it would be nice to have the manual on-line...but they're not...so just break down and buy an OEM manual. Do not even bother with Seloc etc!!!

MAS

 

[tashasdaddy]

Re: 1990 25hp Evinrude low idle ?

kencook, paid a lot of $ for the manual copyrights. i'm sure they are not going to give them away on the internet. kencook (outboardbooks.com) has the manuals thru 1996. Bombardier has the rest.

 

[Firstboat23]

Re: 1990 25hp Evinrude low idle ?

ok went out today no issues will deffinatly get a manual. roller fixed was not issue though... looked into carb again and found that somthing had worked its way up into needle valve once i cleaned it out i readjusted carb and athough my in gear idle is slightly slower that i would like i think i know where to adjust that? it is on the thin metal line that runs just behind the cam follower it has an adjustment slide screw? but all other is excellent ty for all the help everyone