88 Johnson bogging down

T

thebottomfish

Member
So I finally got my boat in the water after the worst water pump experience ever. Great pee stream so at least I got that right!
Idle out of the no wake zone, hit about 8mph and then start pushing the throttle up...motor just shakes, violently and bogs down, rpms won't increase(can't tell you what rpm because I don't have a tach but I would say maybe 2k)
I have three trains of thought if you could let me know if these make sense I would greatly appreciate it!
1. Trying to align the drive shaft I spun the fly wheel an awful lot could I have messed up the timing by spinning the fly wheel? Sorry if this sounds stupid I just don't know enough about outboard motors and I figured because you set the timing on the fly wheel i could have easily screwed it up
2. Carbs are clogged...makes enough sense would pushing in my fuel enrichment switch(pushing the key in) help remedy this and pin point the problem?
3. Water in my gas. I topped off before I laid the boat up for winter but I only had to put in about ten gallons, the rest of the gas no idea how long it had been in there, this year I burned it down to about five gallons and that's what I ran with today, got gas but problem persists...checked fuel water separator didn't seem like anything in there but who knows
Spark plugs all new, gapped and looked slightly wet
Hopefully someone can help me out
 
If i had to guess it's most likely carb related. Could also be the timing arm isn't advancing. If this is the engine in your sig, be VERY careful working on the carbs on it. They are made of plastic and VERY UNFORGIVING if you don't know what your doing with them. They can easily warp, or even worse melt away to nothing if you use the wrong cleaners on them.
 
Thanks for the ideas, timing arm looks like it's advancing, spark at all 4 cylinders, I'll have to check the fuel line at the valve good idea!
When you say the carbs are very delicate, what kind of solution should I soak them in? Or should I just clean with carb cleaner and blow them out with compressed air?
I guess I couldn't have messed up the timing by spinning the flywheel then right?
 
No, spinning the flywheel will not hurt the timing. And carb cleaner is a HUGE NO NO with plastic carbs. You need an ultrasonic with a water based cleaner, or a MILD solvent used for decarboning.
 
If you feel you "must" use something to clean your carbs other than what THEFERMANATOR just mentioned, go to an electrical supply place and get a few cans of plastic safe solvent. It comes in spray cans and is used on circuit boards, switches, etc. Just make sure it says it's safe for plastics.
 
Sounds carb related as stated by Ferm. but be extra careful on the plastic carbs and make sure you put the jets back in the correct location or you will have a worse day.
 
Skools Out said:
Sounds carb related as stated by Ferm. but be extra careful on the plastic carbs and make sure you put the jets back in the correct location or you will have a worse day.
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Or the always fun of reusing the orings and trying to get them to stay in place while you bolt them on because if they fall out of place you will warp a carb tightening it down. I started using trans gel to hold them in place myself.
 
I don't a 10 th as much as these guys know but what I would check is all the fuel filters it's a easy thing to do and you might get lucky and find that's the problem An easy fix also how about the Fuel primer bulb? Is it old maybe calapsing causing no fuel to get by Good luck , let us know how you make out
 
phatdaddy said:
not even sure i want to know what "trans gel" is..
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It's more or less vasoline. It is what you use for assembling transmissions. It is a thick yet easily dissolved grease that is made to allow rubber seals and such to slide together VERY easily, but dissolves almost instantly when it comes in contact with oil so as to not plug up a trans valve body. It's great stuff, and I always have a tub on hand. Works great for carbs and fuel system parts as it allows orings to slide together EASY, but will not plug anything.
 
Well thanks for the advice it was something I found researching, the motor was in s.l.o.w. Mode...one of the temperature sensors was bad, and I found out my warning horn doesn't work! So two quick things to replace, but she ran nice, didn't go out for too long just because I'd rather have a working temperature system.
So thanks for the help, just glad it was something simple.

To get off topic a bit, I was hitting about 33 mph per gps, don't have a tach so I can't tell what rpm it's at but does that seem a bit slow for a 140 on this boat?
 
thebottomfish said:
Well thanks for the advice it was something I found researching, the motor was in s.l.o.w. Mode...one of the temperature sensors was bad, and I found out my warning horn doesn't work! So two quick things to replace, but she ran nice, didn't go out for too long just because I'd rather have a working temperature system.
So thanks for the help, just glad it was something simple.

To get off topic a bit, I was hitting about 33 mph per gps, don't have a tach so I can't tell what rpm it's at but does that seem a bit slow for a 140 on this boat?
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A tad slow. Get a tach on it and make sure it is topping out around 5700-5900 RPM's. The 140 likes to turn up some RPM's to run the best, and wil lactually guzzle fuel if you overprop it.
 
So I've got an Evinrude 140 (87) that sounds like it's doing somewhat the same thing. Already replaced the fuel filter (which definitely helped start-up), and brand new properly gapped plugs (look great after running, not fouled)

Engine runs great under 2200 rpm trolling along, and occasionally it will let me really open it up (was running 33 knots yesterday), but as soon as I pull back throttle (from fast running) the engine will drop down to 2200-2500 rpm and not let me get back up in engine speed. I can NEVER just get on the throttle and get up to speed. (Which I'd like to do because my kids are DYING to go tubing.)

I'm "up north" and not at home so I don't have my usual set of tools, diagnostics, etc. Any EASY tests I can run to see if I can pinpoint the problem?
 
Sounds like classic early carb issues. Most early OMC's require rejetting to run on the gas we have today. I had to do a rather large jet change to my 86 140 to get it to run correctly in the mid range without it falling on it's face. Unfortunately this is a known issue with the early small bore(85-87) loopers.
 
Just to check that it's not going into slow mode like mine was...disconnect the temperature sensors that are in each head, electrical tape the wires just in case, run the boat and see if it still keeps you at the low rpm...don't run it for long because you want to know if your motor is overheating
Does your warning buzzer work properly because this would probably dismiss the issue if you don't hear a buzzer
 
FYI, 115 and 175 "eagle series" carb bodies are no longer available, carb bowls are. The Looper carb bodies(V$ and V6) are NLA as well. You can still get 90 and 150 "eagle Series" carbs. IF you have an OMC with plastic carbs, take care of them
 
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