8hp honda 4 stroke outboat carb is pissin out gas

I just looked at a honda 8hp horsepower for $700.00.... got it fired up but there are the high speed /low speed ports, and right by where if you were to pull the choke out there is a pin hole(there are no threads, but it looks like maybe something was there before.... its definatly suppost to be there, but im not sure if anything is suppost to be in it.. but its pissing out gas.. started up fine, but seems to be flooding itself. im new to motors and just wanna get on the water...., any help would be amazing... and id take ya out fishin on the bay of quite!!!

Jay

Do you know the year of the motor? Can you post a picture of the "pinhole"? Not sure from your description where exactly it might be.

not sure of the year of the model... the serial number is bacs 1000555 i was trying to find out the year of it.... ... thanks for a quick reply.... i gotta go to work... and ill be back later tonight and post a pic by 8:00pm est...... have a great day...

Might need hondadude to straighten me out here 'cause he's the expert but I found this on boats.net and it just says it is pre 1996. Here's the link. Check it out and see if matches your motor.

http://www.boats.net/parts/search/H...ARD ENGINE, JPN, VIN# BACS-1000001/parts.html

i got this here looks to be in pretty good condition.... you can see the ole screwdriver pointing to the hole... not really a pinhole... but ya.. thanks for all the help by the way i do appreciate it! .

second pic is probably the best!!!...

Sorry to butt in...it is a vent for the carb bowl. If there is fuel coming out there, your float valve is stuck open.

Need to disassemble and clean the gunk out.

Mike

Your awesome Mike... if your around the bay of quinte area let me know and ill take ya out fishin' for some pic walleyes!

is $700 Canadian a good price for this motor?

This is a 1987/88 motor. $700 seems a little steep...depending on condition. http://www.nadaguides.com/default.a...=20010&d=17001001181&y=1988&ml=H&gc=MR&gtc=OB

Nadaguides is in US dollars.

A new 8 HP (which actually has more power than the classic 8HP is around $2500 - $3000 US depending on the model.

We have sold the classic 8 after we have gone through them, cleaning carb, new thermostat, new impeller, oil and gear lube etc. for around $750 US. Considering they were used with high hours, the customers were happy to pay and have been happy with the motors.

If you have not purchased yet...you might be able to talk them down a little since the carb needs cleaning. Most dealers would charge about $100 - $200 US to clean it, change plugs and oil and gear lube. Impeller would be extra.

If you have already purchased....clean the carb, make sure it has NGK spark plugs (DR5HS), 10w30 oil, and fresh gear lube and go enjoy a strong reliable motor.

Mike

hondadude said:

This is a 1987/88 motor. $700 seems a little steep...depending on condition. http://www.nadaguides.com/default.a...=20010&d=17001001181&y=1988&ml=H&gc=MR&gtc=OB

Nadaguides is in US dollars.

A new 8 HP (which actually has more power than the classic 8HP is around $2500 - $3000 US depending on the model.

We have sold the classic 8 after we have gone through them, cleaning carb, new thermostat, new impeller, oil and gear lube etc. for around $750 US. Considering they were used with high hours, the customers were happy to pay and have been happy with the motors.

If you have not purchased yet...you might be able to talk them down a little since the carb needs cleaning. Most dealers would charge about $100 - $200 US to clean it, change plugs and oil and gear lube. Impeller would be extra.

If you have already purchased....clean the carb, make sure it has NGK spark plugs (DR5HS), 10w30 oil, and fresh gear lube and go enjoy a strong reliable motor.

Mike

Click to expand...

Hi mike,
since you seem to really know your stuff I was curious if you could help me as well I was reading this conversation because I am also having the same exact problem on the same motor I believe mine is an 1987 is serial #is backs-1001107. Please correct me if I’m wrong. The motor starts then immediately hits the rev limiter and gas is pouring out of the float overflow same as his. I believe the floats getting stuck, but the high rev I’m not sure on. Is that due to an adjustment screw being buried to deep. I just bought the motor and he said it was rebuild with the carb and fuel lines and spark plugs. I’m not sure if all the adjustment screws are set right or where they need to be. I’m looking for a schematic On the carb but can’t find much. Please any help would be greatly appreciated, and I hope your safe with this pandemic.

Ps the motor is going on a 1974 gheenoe lowsider and I’m very eager to take its Maiden voyage.



With great appreciation
anthony

Hi Antgheenoe,
Mike (hondadude) hasn't posted here in quite some time. He has been sorely missed.
This is a very old (11 years) thread.

While I'm nowhere near as knowledgeable or experienced as he, I can comment on your problem on small, twin carburetors as I'm pretty familiar with them.

Your problem sounds like it may be twofold. Yes, it does sound as if the float is badly stuck and it is flooding. But, in order for it to start and run at what sounds like close to full throttle, the engine would need to take in quite a bit of air to burn the fuel. This means that the throttle plate and the choke plate would need to be fully open or close to it.
The throttle cable may be stuck and holding the throttle plate open or the throttle plate itself may be stuck in the open position.
Of course, all of these conditions would need to be investigated and eliminated if found to be case. Removal and disassembly of the carb is likely necessary.
I know of no "schematic" of the carb other than what is published in the HONDA MARINE CARBURETION MANUAL. Currently available from Honda publications for about $40 plus tax and shipping.
It's a really great book for those of us that work on these twin Hondas.
As a matter of fact, hondadude was the guy that encouraged me to buy my first copy. You will learn LOTS if you read it.
However, I reaiize a special manual isn't in everyone's budget so I will say that you can successfully remove, clean and replace your carb IF you take lots of pictures about where things go and ask questions about what is important. I will try and answer your questions if I'm able.

Good luck.

Dear, jgmo
Thank you so much for the info, I’m working on the carb today, I have a manual coming as well, had no idea I could find one for that particular engine. It’s weird the carbs throttle and choke butterflies operate as they should, the throttle linkage looks good and responsive when working the actual twist throttle. There is an adjustment screw that im trying to figure out what it operates I’ll add a photo, you might be able to identify it,
it’s the #6 part in the schematic, I’m not sure how far it should be screwed in and or what it exactly does. My assumption is that it restricts air or gas for tuning the carb. Once again I appreciate all your help in getting my little set up sea worthy( well I guess I mean creek worthy lol)

here’s a pic of my project 74 gheenoe hull and the 87 8hp 4stroke Honda short shaft

#6 is the idle mixture screw. #9 is the idle speed screw.


A typical beginning set up would be to GENTLY bottom out #6 and then back it out
1 1/2 to 1 3/4 turns. Turn #9 clockwise until it just "kisses" the throttle plate linkage and give it another 1/4 to 1/2 turn.

These are only an initial settings so that you can start and idle the engine. Every used engine will want to idle a little differently depending on factors mostly having to do with wear. That being the case, those initial settings may need to be "fudged" a bit. Nothing is really set in stone.

You will want to allow the engine to warm up before trying to achieve a final set. With the engine idling at the rpm you want, screw #6 in until the engine starts to stumble a bit. Then, back it out counting how many turns it takes to have the engine first smooth out and then keep backing it out until the engine starts to run just a bit ragged again. Then turn the screw back in exactly half of the turns (or partial turns) that you counted.

Again, nothing absolute about this "procedure" but it should get you an acceptable idle mix. Finally, adjust idle speed rpm where you want it. These engines like a fast idle...800 to 900rpm....but you can lower it to suit your personal preference as long as it doesn't stall when put in gear.

You might want to remove and inspect the tip on the idle mixture screw. Hopefully no one has screwed it in too tightly. When that happens, the screw tip gets a "step" in it and that could indicate the seat is damaged. Sadly that can make getting a mixture setting that is consistent hard to achieve. The seat isn't repairable.

Good luck and let us know how you get on.

Update: I have gotten the engine to start and run flawlessly. A new issue has arrived as well with that. There seems to be water and smoke coming from the shifting shaft by the gear rod. Do I have to replace the seals in the lower unit, I am planning to change the gear oil as well, I’ll just do it all at once if the seals are busted. Please let me know you opinion, I will post a photo showing where it’s coming from

once again your the best, hope your safe, and I’ll talk to you soon hopefully lol.

I haven't seen anything coming from there before and, since you say you see water coming up it's sort of alaming. The regulator/rectifier for your charge system is right there in the photo.

These engines are fairly notorious though for burning out the exhaust pipe gasket. This usually results in the engine stalling out with the hood on and then, almost like magic, running perfectly when the hood is removed. Only it's not magic. The exhaust fumes from the bad gasket enter the intake and starve the engine for oxygen to burn the fuel.

So, seeing smoke enter the engine compartment might indicate that the exhaust gasket has failed. But I'm not sure about the water getting up that high

To repair the exhaust gasket, the engine must be removed from the oil case.

You will want to have the shop manual if you choose to do this job.

This isn't a very hard job to do and it also gives you opportunity to access and clean (or replace) the permanent oil screen and swab out the oil sump. Both of which can be pretty sludged up after years of operation.

Just watch out for the "hidden bolt". It's not really hidden but it's caused many a broken oil case when missed and force is used to try and separate the engine from the oil case. A $1200 mistake!

Thank you for the info, I’m going to do a complete lower rebuild with new seals and gaskets, while I’m down there I’ll check out the exhaust gasket because that really seems like it may be it when you explained it. Not a bunch of water is coming up the shifting linkage, just a couple of drops, but the smoke I think is that exhaust gasket being fubard like you said. I bought the shop manual so I’m ready to go lol, Thanks again, you are helping me so much. Have a great day.

You will, at a minimum, need the exhaust gasket plus a new engine to oil case gasket and the very small oring that is "nestled" inside the oil case gasket.

These items are available at boats.net and should be renewed. Don't try to reuse any of these even if they look ok.

I also recommend a new seal be used at the top of the water tube where it enters the engine block. Be aware that the seat for this seal may be "eroded" if the seal has moved for any reason. The seat can be repaired by using industrial epoxy to "sculpt" a new seat. I have drilled tiny, shallow holes in the block there to help anchor the epoxy solidly.

Good luck and have fun.