Jonny 150 Looper Stumbles

[Fl_Richard]

Same motor as pervious post. 1995 non Ficht 150 Looper. Runs great. Well usually. Symptoms are starts right up runs fine for a until I get to the inlet get outside, run up to 4500 turns. Cruse along and boat feels like it's hit a bag in the water. Tach drops noticably but intermittantly soon followed by engine almost dying. Some times it does die. When it does it 's hard to start. Wait a few minutes it will start I'll enjoy it all day long then next week out same problem.<br /><br />Where Do I start? Found a simular problem in post "87 140hp Johnson Intermittent problem" but no real resolution. Thanks for any help!!<br /><br />Richard

 

[marinemech]

Re: Jonny 150 Looper Stumbles

could be a fuel problem try priming the motor as its dying see if it comes to life<br />could also be a spark problem preform spark test when symptom present if it only has spark on 3 cylinders disconnect shift switch see if spark returns<br />if shift switch is problem verify cable adjustment if cable is ok install new shift switch<br />there are a few other things that may cause your symptoms but try to narrow it down some before buying a lot of expensive parts<br /><br /><br />if this is the motor with temp gauge problem clean out or replace other thermostat motor may be going into s.l.o.w.

 

[Fl_Richard]

Re: Jonny 150 Looper Stumbles

I know it's not s.l.o.w. this happens once or twice per outing. Usually in the morning. <br /><br />After it happens I can drive at 5000 turns for hours and it's fine. <br /><br />It's like a switch gets flipped, run crappy/run great.<br /><br />Shift switch though... intermittant closure? Do they go bad? This problem can happen from 1000 rpm up.

 

[marinemech]

Re: Jonny 150 Looper Stumbles

i have seen quite a few shift switches go bad usually a sticking button this could be the source of your problem

 

[marinegrh]

Re: Jonny 150 Looper Stumbles

is this an ois motor, optical ignition system or oh its stuck for you omc fans.....give me some more info and ill get you started in the right direction....get a model and serial number of it and tell me if its an ois motor or not........is your vro still hooked up too,and give a little history the dates back a few years good luck

 

[Fl_Richard]

Re: Jonny 150 Looper Stumbles

Yes it is OIS. Just last week I replaced the VRO pump,geez 255.00 for a plastic part!!! Engine details as follows:<br />Johnson 150HP 1995 Looper<br />Model J150NXEOM<br />S/N G03792920I've only had the boat since August 04 and it's just gorgeous. Twin 150's had 200 hours on them when I bought it, (300 now) it was stored in a boat storage building by a guy who lives in Michigan, and vacationed in Marco Island Florida. So not used often or hard. Hull had not a scratch on it when I bought it, of course I scratched it on day one Engines have corrosion inhibitor sprayed all over them so they are in excellent mechanical shape. <br /><br />Intermittant cutouts started a few outings ago very intermittantly, now I can count on it happening at least in the first hour of every trip.<br /><br />Many thanks!!!<br /><br />Richard

 

[Dhadley]

Re: Jonny 150 Looper Stumbles

All 60 degree carb'd E/J motors have the OIS ignition system. Your 1995 150 never had a VRO. Its a fuel/oil or a straight fuel pump. Why did you replace it? <br /><br />If you suspect the shift switch just unplug it. If your motor idles low enough, like it should, you dont need it anyway. Follow the wiring diagram in your service manual and just take it out of the loop. Be sure to close the loop or one side will not shut off with the key. Its very obvious how to do it once you look at the diagram.<br /><br />It almost sounds like youre losing spark on one bank. When it happens you should check for spark on all 6. It could be the stator or the pack. If it is the pack, change the eye at the same time. One may come with the new pack.

 

[Fl_Richard]

Re: Jonny 150 Looper Stumbles

Replaced the what I thought was VRO pump.... It mixes oil and gas... has the four wires coming out, power ground tach and oil alarm. The oil alarm is why I replaced it. It sounded a few months ago once while rinsing out the motors. Next time out it was silent, it ran for a few weeks then a couple of weeks ago it started sounding again, this time it never stopped. Replaced it figguring I could rebuild tho old one and have a spare. Havent looked for rebuild parts yet. <br /><br />Whats the "Eye"? And while I have your attention, where is the water temperature sensor located? My manual makes no mention of it... I see temperature switches, I assume they are for SLOW.<br /><br /><br />Thanks for all your input. I'll be taking it out again tomorrow, I think have an old timing light laying around, I'll try and isolate the problem further.<br /><br />Thanks again,<br /><br />Richard

 

[Fl_Richard]

Re: Jonny 150 Looper Stumbles

For those of you who give a hoot, the problem was bad power packs. Mechanic said a 220.00 part and 4 hrs labor. Just to reiterate this engine is a 1995 looper V6 150 HP - Optical ignition.