1995 Johnson 88Hp wont stay running

[shep75]

I am getting frustrated with my engine. the problem started at the end of last summer. It will start up and and miss really bad and like it was only running on 2 out of 4 cylynders. I changed the fuel pump, put fresh gas and put new plugs in. It doesnt always do this, I might take it out one day it it will run fine and the next time I will sit at the dock and it will take 15 min before it calms down enough to where it will idle.

Yesterday I went out and cleaned all the ground connections and leads on my coils. The grounds were green and corroded really bad. Now I took it out after that and it starts up fine no missing. It ran for about 10 mins so I felt comfortable to take it for a spin so after I left the dock it went about 1/8 mile and died in the middle of the lake. Would not start like it was flouded. I pulled all plugs and cleaned what i could and installed in different cilynders and it ran for about 5 mins and did the same thing. This went on for about a half hour. It has lots of power and gets on plane fast and goes the top speed that it did when I bought it. Just seems to be a starting and low speed problem. After I come back from boating and the engine is warm I go the the dock and shut it off and by the time I get back to start it up to put it on the tailer it wont start agin like it is flooded. I take it home which is about 15 min and it will start again.

 

[tashasdaddy]

Re: 1995 Johnson 88Hp wont stay running

welcome to the iboats forums. sounds like something electrical is getting warm, and cutting out. green corroded connects can blow the amplifer. what did the plugs look like? did you check spark when it wouldn't start?

 

[shep75]

Re: 1995 Johnson 88Hp wont stay running

Plugs looked wet with oil on them. They still had spark when I would put the plug against the block. what gets me is that I can run it for 45 min with no problem as long as I am above like 1500-1800 but the problems are below those rpms like in the no wake zone area. If I can catch it in time right before it dies hit the throttle and gun it a couple of times that will help but if i dont catch it and it stalls that is when i am stranded for about 10 min pulling plugs.

 

[Solittle]

Re: 1995 Johnson 88Hp wont stay running

Next time you go out take a squeeze bottle filled with pre mix. When it starts to run rough squirt some of the pre mix int the carbs. If it smooths out then the problem is fuel related. My guess is crud in the carbs.

 

[shep75]

Re: 1995 Johnson 88Hp wont stay running

I would think adding more fuel to the carb would make it die more, but that is me. What in the carb would make it quit or cause the plugs to foul out when at low rpm but run great in the upper rpms without any hessitation or problems.

 

[footballhi]

Re: 1995 Johnson 88Hp wont stay running

check your idle jets in the carbs that are missing at idle,

 

[ShawnQ]

Re: 1995 Johnson 88Hp wont stay running

Shep,

You and I have the same engine, and it sounds like we have the same problem.

If idling and the issue occurs, my engine will sound as if it is 'bogged down', running on only 2 or 3 cylinders, or starving of fuel...I can't tell which.

If I give it gas, it will rev up some, but doesn't sound 'normal', still sounds choked, and doesn't have enough power to plane. Then, all of the sudden, it will 'kick in' and run like normal, no probs.

My engine is just like yours - runs excellent at high RPM's, spinning the 4 blade prop to 5200+ without a problem. BUT, if I idle around too long, I have to rev it every so often to keep it running normal. I've never had it fail at high RPM, only low RPM.

One thing I noticed on my last trip is that when I primed the fuel bulb (on the last occurence of this problem), the idle cleared up. I didn't get to try it a second or third time to test if it helped, only once...so you may try this next time you run into this issue.

This led me to believe that I am having a lack of fuel....but again, I can't support it as I only did the 'fuel bulb priming check' one time.

I will say this: Every time I run my boat, I pull the fuel line off the engine and let it run out of fuel, so as not to gum up the carbs if I am going to let it sit for a month or so. When I pull the fuel line, and it is just about out of fuel, I will give it throttle to make sure it burns as much fuel out of the carbs as it can. When I do this, the engine sounds a LOT like it does when I am having my low RPM idle problems....coincidence? I'm thinking it is starving for fuel, haven't figured out why yet.

Here is the thread I've got going right now - read through it, it may help:
http://forums.iboats.com/bbBoard.cgi?a=viewthread;fid=28;gtid=1268870

Here is what I've replaced:

Replaced All fuel lines and clamps to insure there are no air leaks
Replaced Fuel Filter
Replaced Primer bulb - Replaced again because I hear they are sometimes defective from factory
Replaced Spark Plugs
Replaced Spark Plug Wires
Rebuilt the carbs, and gave them a thorough cleansing (they were already clean though, really looked great)
Inspected the Fuel tank pickup - it is clean.
Checked fuel tank vent - it is functioning

I was about ready to replace or rebuild the fuel pump...but noticed it didn't help you...so I may wait on that.

I have not cleaned my grounds, but they don't look too bad. Maybe I'll do that next because it's a freebie.

I'm anxious to see how your repair goes, as I feel we've got similar problems.

Hopefully me telling you what I've already done, and knowing I still have problems, may help you out and prevent you from spending some of the unnecessary dollars that I've spent.

Good luck! Feel free to contact me direct if you would like. I wouldn't mind discussing our engine issue on the phone and seeing if it is truly the same symptoms. It sure sounds similar. Ironic to say the least.

S_Queeney@hotmail.com

Take care,
Shawn

 

[iwombat]

Re: 1995 Johnson 88Hp wont stay running

I'm willing to bet it could be a sticky float too. But, before you go any further down a rat-hole with the carbs you should do a proper spark test. Does it jump 3/8 gap with a hot bright spark?

 

[ShawnQ]

Re: 1995 Johnson 88Hp wont stay running

I'm willing to bet it could be a sticky float too. But, before you go any further down a rat-hole with the carbs you should do a proper spark test. Does it jump 3/8 gap with a hot bright spark?

Wombat,

What do you consider a proper spark test and how does one do it?

Thanks
Shawn

 

[iwombat]

Re: 1995 Johnson 88Hp wont stay running

Should be a thread on here somewhere . . . I'll look around for ya.

 

[iwombat]

Re: 1995 Johnson 88Hp wont stay running

Gah! Only about a million posts on spark test, but I can't easily find one that explains the procedure. There's also nothing in the FAQ (we should really fix that).

Anyway, what you want to do is rig up, or purchase a spark tester. It's basically a way to hook a plug wire up to a piece of metal cross a fixed gap and go to ground. One you can buy looks like this:

You can also rig one up out of nails and wood. It's pretty easy to make a tester that you can hook all your leads up to so you don't have to ground any out that aren't being tested.

The procedure goes something like this:

Remove spark plugs, ground out the leads you're not testing with nails/wire/whatever. Set the gap in your tester to 3/8" and turn your motor over. You should see a nice hot spark jump the gap. If not, you've got ignition issues.

Maybe someone can post some pictures of homemade multi-lead testers.

 

[ShawnQ]

Re: 1995 Johnson 88Hp wont stay running

I think I understand the concept and can figure it out...

Thanks for the info! I'll give it a shot, although I feel my problem is fuel related.

I don't mean to intrude on this post too much, so I'll back off until I know for sure whether or not Shep thinks we have the same problem.

Take care,
SQ

 

[iwombat]

Re: 1995 Johnson 88Hp wont stay running

Well see, that's the whole idea behind doing a spark check. You want to eliminate the possibility of an ignition problem before you go rebuilding those carbs.

 

[iwombat]

Re: 1995 Johnson 88Hp wont stay running

Of course, now that i've said 3/8" about a zillion times I think the correct spark-test gap for that motor is 7/16". Look in your manual. Anyway, you get the picture.

 

[tashasdaddy]

Re: 1995 Johnson 88Hp wont stay running

i'd do the spark test (tester $10 auto parts store), and a compression test. due the easy thing first. then tear things apart. they can run find on 3 cylinders at high speed. trouble shoot in order. if you have a hot blue spark, jumps 7/16 inch, and compression on each cylinder over 100psi, and within 10% of each other, then look at the carbs.

 

[shep75]

Re: 1995 Johnson 88Hp wont stay running

Think I found the problem, I went out to check on some more things and I started the motor on the hose in the driveway and it acted up again. I pulled the black with yellow stripe wire off that goes to the power pack wich is the kill swicth wire and the idel smoothed out like it was running on all four. I let it run for a little while and no more problems. As soon as I pluged the wire back it it would die and it was hard to start. I got the multimeter out and checked the wire and with the key in the on position and the kill lanyard in, I checked continuity and it had a fast beep,beep,beep,beep,beep for as long as I kept the lead on the wire. So when the wire is connected and the engine running it was turning the power pack on and off as fast as it could. I am going to take the boat at soon and will let you know how this all works out on the water.

 

[tashasdaddy]

Re: 1995 Johnson 88Hp wont stay running

you will have to manual flood it to kill it, with the black yellow wire disconnected. tells me you may have and ingintion switch shorting out. or the kill wire are the switch touching something it shouldn't. to flood turn the red knob on the primer to the opposite postion.

 

[shep75]

Re: 1995 Johnson 88Hp wont stay running

The kill switch was the problem all along, went out today and it started up without any choke and it ran all day without any problems and it purrs like a kitten now. Thanks for all the help and inputs

 

[iwombat]

Re: 1995 Johnson 88Hp wont stay running

Good find. Even better that you found it before spreading the carbs all over the bench.

 

[ShawnQ]

Re: 1995 Johnson 88Hp wont stay running

Congrats shep.

Any idea WHERE the kill switch wire is messed up? Is it the wire iteself, or the actual switch?

Just wondering if you traced it enough to pinpoint the problem or not.

I'm heading out to tinker with mine right now...wish me luck!

Planning to check the kill switch wire first, then the crankcase to fuel pump hose, then possibly spark check, etc.

Take care,
SQ