Honda 4stroke question.

[GeordyBass]

I usually am the one giving out some advice, so now It's your turn! J/k....lol.... Ok on to my question: I took out my 1991 Honda 8hp 4 stroke outboard to castaic. It ran just fine,idled quietly and put my 13' gregor on plane pretty well. But I started having problems (the Usual...lol...). The motor at one point started "coughing".... It didn't have much power and "coughed" a lot. I just recently put in a brand new Carb btw. It would be running perfectly then shut off.... Afterwards I started it but had to keep the Idle Up high and if I kept it low it would "cough" and shut off. It cleared up I guess, then ran perfect and did it yet again. I opened the cover and when It would start the "coughing" I could see light grey smoke coming out each time it did it! The oil level was at 90% and it pee'd ice cold water..... I'm not too familiar with smaller 4 strokes really so any Info I'd appreciate it! :-)

[Kevman]

Geordy,

Off the top of my head...

1. Bad (old) gas--use nothing older than 30 days--put old gas in your truck instead.
2. Water in carb bowl--drain it with the drain screw at the bottom of the bowl.
3. Coil(s) breaking over--will mainly cause the motor to die when it gets hotter from running for a while. Check for cracks in the coils.
4. Bad spark plug(s)--fouled or old weak spark--check with plug tester and if bad or really old and anode eaten away or dirty, replace.
5. Dirty carb--even with a new carb it can become fouled in one use with dirty or old gas, especially with this ethanol crap we have now--if there is any chance whatsoever that your carb is dirty I would disassemble, soak overnight in carb cleaner, blow out all orifices with compressed air and reassemble.
6. Exhaust leak--run with the cover off and see if it still coughs.
7. Might need to adjust your air/fuel mix screw--what do you plugs look like? Black and ashy, light toast color and clean, or wet/oily?
8. Air leak in fuel system--try squeezing the fuel bulb while it is coughing. Does that stop the coughing?
9. Spray gas in the carb throat when it is coughing. If it stops coughing you are not getting enough fuel. Possible fuel pump air leak--replace diaphragm.
10. Check compression on all cylinders just to rule that out. What are your readings?
11. Inline fuel filter clogged--check and replace if necessary.

Report back with what happens when you check these things. Without knowing anything, I'm thinking air/fuel mix screw adjustment or fuel delivery problem.

Kev

[GeordyBass]

Ok I will and I'll tell you later on today. Gas is not older than 1 or 2 weeks. Also, the Carb is brand new out of the factory and I adjusted it exactly to the old one. The old one was all gummed up and I didn't want to bother cleaning it up. I also cleaned the Fuel pump and it works just perfectly. At WOT the water pumping out is as cold and the powerhead is barely warm so I can keep my hand on it all the time.... When cover opened up it still coughs more like pops if I think of it.... It backfires some light grey smoke out of the carb. I haven't checked the plugs yet so I'll keep you updated,,, thanks.

[bruce watson]

GB, you said that the motor was a 1991. Back then boats did not have gas lines that were alcohol resistant. Today in California our gas is a mix of 10% ethanol. Last year I had to replace all my gas lines inside and outside the motor with new alcohol resistant lines. I also had to rebuild the injectors and put on new filters. I had Jimmy, who did the work, also put a waterseparater on for extra filtration. Jimmy over at Mac marine only charged me a little over $200 for all this plus my annual.

[GeordyBass]

GB, you said that the motor was a 1991. Back then boats did not have gas lines that were alcohol resistant. Today in California our gas is a mix of 10% ethanol. Last year I had to replace all my gas lines inside and outside the motor with new alcohol resistant lines. I also had to rebuild the injectors and put on new filters. I had Jimmy, who did the work, also put a waterseparater on for extra filtration. Jimmy over at Mac marine only charged me a little over $200 for all this plus my annual.
Thanks! I'll see if I do it myself I re-checked the year and It's a 1994 btw pre-silver color,,,

[CAPT'N]

Geordy,

Check the choke,if it is cable operated it may be sticking on. Then, if the carb has a float bowl, then check the float bowl height, as that can cause most of the problems you have with the outboard.

Capt'n

[Fishthewhaler]

i have a remote connection kit for that motor that changes from tiller to steering/throttle connects if you are interested. It is for 8hp-9.9 90's motors.
put an inline glass see thru filter and run the motor, watch the glass bowl it should stay 80percent full, and NOT run out of gas. If it starts running out of gas its a pump, I think it is your new carb settings. Its possible your old carb was worn enough that a new carb might run on those settings, but more like Factory specs. Set all according to honda specs. also,how was it running before you changed carb? If you're experiencing same problem, could be an ignition problem.
FTW

[GeordyBass]

i have a remote connection kit for that motor that changes from tiller to steering/throttle connects if you are interested. It is for 8hp-9.9 90's motors.
put an inline glass see thru filter and run the motor, watch the glass bowl it should stay 80percent full, and NOT run out of gas. If it starts running out of gas its a pump, I think it is your new carb settings. Its possible your old carb was worn enough that a new carb might run on those settings, but more like Factory specs. Set all according to honda specs. also,how was it running before you changed carb? If you're experiencing same problem, could be an ignition problem.
FTW
The old carburator was really bad and not worth fixing,,, All the needles were gummed up and stuck to the carb itself. Rebuild is about $150,,, new carb is $100.

I also checked the plugs and they were black and burnt. Ny dad went to castaic today and I'll tell you guys how it went,,, The fuel pump works just perfectly and always holds pressure 100%...

How much do you want for the setup FTW?

[Kevman]

Black, burnt, ashy plugs means it's running too rich, bro. Too much gas, not enough air in the mix. You need to adjust your air/fuel mix screw to give more air. You can google up the exact instructions for your motor if you don't have the shop manual. I'd just buy the shop manual for $40 or whatever if you can. Make sure to get the exact Honda one for your model--much better than generic ones from Seloc or whatever.

If your mix is significantly too rich, it could definitely cause the problems you describe. Also the fouled plugs themselves could be the problem.

Ideally the plugs should be a sort of golden toast color and clean. I'd replace those plugs. They are cheap.

Good luck!
Kev

[GeordyBass]

Black, burnt, ashy plugs means it's running too rich, bro. Too much gas, not enough air in the mix. You need to adjust your air/fuel mix screw to give more air. You can google up the exact instructions for your motor if you don't have the shop manual. I'd just buy the shop manual for $40 or whatever if you can. Make sure to get the exact Honda one for your model--much better than generic ones from Seloc or whatever.

If your mix is significantly too rich, it could definitely cause the problems you describe. Also the fouled plugs themselves could be the problem.

Ideally the plugs should be a sort of golden toast color and clean. I'd replace those plugs. They are cheap.

Good luck!
Kev
I forgot to check em before hand,,, I think they were just bad from before I bought it.... Always a first... My dad bought some new ones I guess so we'll see if the problem is gonna later on...:Cool:

[GeordyBass]

Woo hoo! Problem is gone! Put in new plugs and adjusted the carb a bit. Dad said it ran flawlessly and even used less gan...no smoke... 1 pull every time.:Envious:

[Fastfish]

The OEM carb is always on the lean side of the mixture equation by simply richening the low speed you'll get a better running motor I played with one very close in age to ur own and was able to get that motor to idle down to a incredibly low rpm while in gear and then have it snap on demand up into the power range.

Keep in mind that everything else has to be in good condition to do that valve clearences need to be right on the money or to the loose side doing a cylinder leak-down would be advisable as well.

Fastfish/Geoff

[Kevman]

Right on Geordy, those were #4 and #7 on my list. ;)

Glad you got it running great! Now where's the fish pron?

Kev

[GeordyBass]

Right on Geordy, those were #4 and #7 on my list. ;)

Glad you got it running great! Now where's the fish pron?

Kev
whats "pron"? lol j/k,,,

I'll put up a short report soon.

[Kevman]

whats "pron"? lol j/k,,,

I'll put up a short report soon.

Didn't want to offend the parents here or corrupt the little kiddies, you know?

Gotta keep it clean. That's how I roll! lol

[GeordyBass]

Didn't want to offend the parents here or corrupt the little kiddies, you know?

Gotta keep it clean. That's how I roll! lol:Secret:.......

[Fishthewhaler]

The old carburator was really bad and not worth fixing,,, All the needles were gummed up and stuck to the carb itself. Rebuild is about $150,,, new carb is $100.

I also checked the plugs and they were black and burnt. Ny dad went to castaic today and I'll tell you guys how it went,,, The fuel pump works just perfectly and always holds pressure 100%...

How much do you want for the setup FTW?

I paid over 100 for it from Honda. I 've had it for a bit but it still in the package. 60 bucks and its yours. I'll have it for a bit, I'll put it on ebay soon if not.