V4 Rough Idle: Update

ReelDrag

Petty Officer 2nd Class
Joined
Jul 12, 2002
Messages
143
Update to a problem I posted a couple of weeks ago about my 92 Johnson 115. I had found 1 of the recirculation valves not working so I replaced them all. I went ahead and pulled the flywheel and found a crack in the original stator, so I deceided to replace all of the electronics since everything looked to be 1992 (stator, trigger, powerpack, coils, regulator, key switch). I also went through the carbs for the second time to make sure they were perfect. Got it running on the hose today and it idles perfect UNTIL I trim it down all the way, and then it drops a couple hundred rpms and idles rough. Trim it up a little and it smooths out. Could the trim switch be grounding out and causing this? I noticed the trim gauge needle jumping around like it's grounding when I trim down all the way. Sorry for the long post but I'm at the end of my rope here.
 

OBJ

Supreme Mariner
Joined
Dec 27, 2002
Messages
10,161
Re: V4 Rough Idle: Update

Hey ReelDrag, next time you got it running and trimmed all the way down and it starts to idle rough, lift up on the wire harness' where it goes into the pan. If the smooth idle returns, you may have a chaffed wire or two in the wire harness.
 

Solittle

Fleet Admiral
Joined
Apr 28, 2002
Messages
7,518
Re: V4 Rough Idle: Update

I have a pair of 110s & had a problem like you describe. A wrench advised to trim up a bit thus changing the level of fuel in the float bowls a tad. Problem solved.
 

ReelDrag

Petty Officer 2nd Class
Joined
Jul 12, 2002
Messages
143
Re: V4 Rough Idle: Update

To OBJ: Tried moving the harness around with no change, however, did get a slight idle change when I moved the main harness plug ( big red one). I pulled it apart and found some corrosion on the contacts. Cleaned them the best I could with some rubbing alcohol. Don't know if it made any difference or not, getting to late to start it up. (I hate deed restricted neighborhoods.) To SoLittle: If it's a fuel problem I can't see how trimming up will help when you"re bouncing around on the water. The fuel isn't going to stay level.
 

walleyehed

Admiral
Joined
Jun 29, 2003
Messages
6,767
Re: V4 Rough Idle: Update

What you are experiencing sounds like normal crankcase scavanging to me.<br />make sure the drain line from the under-side of the intake cover is hooked up to the crankcase fitting and the cover.<br />For the electrical connections, use some di-electric compound, known as DC-4 and several other brand names.
 

ReelDrag

Petty Officer 2nd Class
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Jul 12, 2002
Messages
143
Re: V4 Rough Idle: Update

Thanks walleyehed. I made sure everything is hooked up correctly. I thought the crankcase may be loaded with oil residue. When I took out the old recirculation valves fuel poured out of the ones that weren't working. I need to get it in the water and give it some wot to clear it out.
 

ReelDrag

Petty Officer 2nd Class
Joined
Jul 12, 2002
Messages
143
Re: V4 Rough Idle: Update

Would it be better to use a conductive grease on the plug contacts? I know dielectric grease will stop corrosion but it doesn't conduct electricity.
 

kgw

Petty Officer 2nd Class
Joined
Feb 28, 2004
Messages
120
Re: V4 Rough Idle: Update

Realdrag,<br />Try some "DE-OXIT",made by Caig labs, they have a web site. I used this cleaner on all types of circuit board and plug connectors before i retired from the electronics world. great stuff
 

ReelDrag

Petty Officer 2nd Class
Joined
Jul 12, 2002
Messages
143
Re: V4 Rough Idle: Update

Got it on the water today and it ran perfectly. Easy starting and more power than I remember it having in the 5yrs that I've owned it. Since I replaced all the electronics it is hard to pinpoint the cause of my original idle problem, but an educated guess would be the stator or the recirculation valves. Thanks for all the replies and suggestions. Until next time, Rick
 
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