2000 Johnson random skip at idle.

Eemjr

Cadet
Joined
Jul 21, 2014
Messages
14
I'm going to provide as much info as possible, please be patient. Boat was running great came home flushed motor. Week later changed plugs ( gaped to .030 ) changed fuel water separator. All because had been a year since done. Month latter peeped boat to take out while idling on the muffs I noticed a random skip. Took boat out figured just needed running well it wouldn't run above 5100 rpm. It would shake and cough and misfire. Back off throttle all good. I went back to the old spark plugs, mixed a portable gas tank with fresh gas/oil and even swapped the power pack with a known good one. I unplugged the rectifier per the CDI troubleshooting guide, and finally after all that I noticed a carb leaking around bowl. Thought I had it. Rebuilt card today still no change. One OMC mechanic said get rid of the champion plugs and go NGK another says stay champion. I just want to fix my motor. Guy's I need your help. Thanks
 

Eemjr

Cadet
Joined
Jul 21, 2014
Messages
14
Yes I have the ois sensor I haven't thought about that because it went out a year ago and the motor wouldn't start at all. I'll give that a try a buddy is a part time marine Mechnic he has one he keeps for test purposes. I'll get it next week and let you know. What's your thoughts on champion plugs vs NGK?
 

Eemjr

Cadet
Joined
Jul 21, 2014
Messages
14
Well couldn't get optical test sensor but I did check timing wheel for cracks or damage found none, I checked/wiped clean the optical sensor (no chemical used). I also pulled plug wires one at a time noticeable difference on a couple cyclinders not so much on the rest🤔 I also found the port tempature sensor not tightened down. I cleaned the area it mounts in and re-installed. Started raining I had to stop. Will start again tomorrow.
 

jakedaawg

Rear Admiral
Joined
Jun 26, 2012
Messages
4,275
Model # would help someone to help you. They made a lot of different motors in 2000
 

Eemjr

Cadet
Joined
Jul 21, 2014
Messages
14
Johnson 150 oceanpro J150vxsss and any help is greatly appreciated. I'm still troubleguessing
 

jwall116

Petty Officer 3rd Class
Joined
Sep 4, 2015
Messages
97
I want to watch this rebuild take place! Sorry about your broken ring.

Also had the same question about the spark plugs... below is my experience.

I ran the NGK BPZ8HS-10 for a few weeks, didn't notice any misfires or difference in performance over the Champs. Forum searches pushed me to switch them to Champs, so away with the 3 week old NGKs and thrown into the trash. Champs put in their place and that was 6 months or nearly 50 hours ago. Same plugs are still in the engine. They are slightly wet when i inspected them last but far from fouled or worn. NGK is actually more expensive in our case. Either way, plugs are cheap and I dont mind changing them every year.

Whats the difference? Below is quoted from Vic S. from iboats.

"The facts are that OMC recommended only the Champion Q series plugs with all their engines with CDI.
Q series plugs are low resistance inductively suppressed plugs.
Only the Z series from NGK are inductively suppressed.

NGK plugs have bad reputation when used in Johnson and Evinrude outboards which I suspect is not because there is anything wrong with NGK plugs, au contraire, but because in the absence of inductively suppressed NGK plugs until relatively recently, resistor plugs were recommended and used with sometimes disappointing results.

The hard line approach would be to respond to all questions about plugs by saying use only the engine manufacturers recommended plugs! In the case in point this amounts to QL77JC4 or QL78YC.
I prefer the softer approach, particularly with questions originating in the UK where Champion plugs are not so readily available, namely to suggest the nearest equivalent NGK plug. In this case BZ7HS-10."
 

Eemjr

Cadet
Joined
Jul 21, 2014
Messages
14
So jwall116 what has brings you to the conclusion that this is a broken ring? And does anyone else out there feel the same? If so please tell what makes you think this. Thanks
 

flyingscott

Fleet Admiral
Joined
Apr 8, 2014
Messages
7,985
I have no idea what jwall is talking about think he posted in the wrong post.. Run the champion plugs they do tend to run better in Evinrudes. What is the compression and does spark jump 7/16".
 

jakedaawg

Rear Admiral
Joined
Jun 26, 2012
Messages
4,275
I agree with flying Scott, start with the basics. Comp test, open air gap spark check, and fuel sample into clear jar.
 

Eemjr

Cadet
Joined
Jul 21, 2014
Messages
14
Done fuel test looked good no water but still testing on portable tank mixed 50/1 the vro was eliminated two years ago. Attempted spark gap over weekend really didn't see the blue spark on any cyclinders possible not grounded good enough will try again. Haven't done compression check however it was done at the shop a year ago and had 105 or 110 can't remember which on all cyclinders. When I pulled the plug wires one at a time #3 cyclinder is the only one that didn't seem to have any change. That's the carb that I rebuilt cause to was leaking maybe it's got a jet clogged, and I'm not comfortable messing around with air/fuel mixture screws I been told you can burn up a motor real quick. Going to try spark gap again after I fix a wire I can get a good ground with. And I have been talking with the shop I like and trust ( Becks outboard in Jacksonville) I may carry to them so I can finish my other projects I know how to do and have boat fixed at the same time. If so I will post findings so others can be helped from what I find out.
 

jwall116

Petty Officer 3rd Class
Joined
Sep 4, 2015
Messages
97
WHOOPS! Yes the wrong post. No idea how that happened.

Yes. Run the champs over the NGK's.
 

Eemjr

Cadet
Joined
Jul 21, 2014
Messages
14
Ok guys thanks for all the advice/suggestions but with all the other things that I need to do building up, my job and good fishing weather coming to an end I decided bite the bullet and the to take the boat to the shop today. I will post results so maybe other people can benefit from this.
 

Eemjr

Cadet
Joined
Jul 21, 2014
Messages
14
Ok guy's the job had me out of town for a bit but as promised here are the results of taking my boat to the shop. The high speed jets was wore out I was told that every three to four hunderd hours they need replacing that's what what was causing it not to run over 5000 rpm. Next I had a cracked ( not leaking yet )carb bowl and some trash behind the idle jet causing the skipping/popping at idle. So 428 dollars latter it idle's like a dream and runs 5700 easy with a four blade stainless. Also the guy's told me that the two carbs they had to pull apart that the clip that holds the float needle was installed incorrectly. They need to be installed from the float to the front not from left to right. They can work there way out and prevent the float from floating. Also they recommend I run marine gas with no additives. Guys I learned some things and I hope this helps someone out there.
 

racerone

Supreme Mariner
Joined
Dec 28, 2013
Messages
36,047
I firmly believe that there are some shops / " service advisors " who will know that some novice customers will believe these stories.------They then know that novice will come back because of the exceptional trouble shooting skills.
 

lmuss53

Lieutenant Junior Grade
Joined
Sep 9, 2008
Messages
1,227
These last three post are right on the money in my opinion.

I trust no shop, sadly I think they all become a bit of a pirate from time to time and blend fact and fiction as they see fit to pad the bill.

I'm glad they got your boat sorted out and the bill didn't seem too outrageous.

I worked on a 20 year old Merc 9.9 over the summer, the guy paid $1400 for it and it would not start the first time he put it in the water. He took it back to the shop and they told him "you must have hit something with it, sorry no warranty on used motors."

Champions only in OMC motors for me.
 

Eemjr

Cadet
Joined
Jul 21, 2014
Messages
14
Well guys contacted four other johnson repair shops. I ask about high speed jets wearing out over time. Got the same answer from all of them. About every 400 hours they need replacing, and the symptoms become present over time. Slight recession in rpm's at wot that gets worse over time, extra gas consumption that gets worse over time and eventually motor not able to burn all the gas dumped in it. And marine gas, lets see no ethanol, no extra additives just my oil 🤔 Has to be a good thing. Bottom line none of OUR troubleguessing got to running properly and they did. I just wanted to hopefully help someone else out. So take it for what it's worth and keep dealing with your lowering rpm's and extra gas consumption. I'll be enjoying my time on the water.
 
Top