Any Honda Outboard Experts?

Quickstep192 · #1 (**permalink**) 05-09-2007

During Spring comissioning, I had a problem with my Honda 8HP having a problem at idle. I fixed this by cleaning the idle jet..... or so I thought.

The problem returned and was worse this time - At this point, the engine starts right up when fully choked and will run at half choke and high throttle. If I put the choke in all the way it stalls; if I back off the throttle it stalls. I got tired of working on it on the boat, so I took the carb off and brought it to the house. I've dissassembled the whole thing and cleaned every part. I didn't really see anything that looked gunked up, but some of these orifices are mighty tiny. I'm replacing every gasket and o-ring in case they were affected by the carb cleaner. I'm hoping this will fix the problem, but if not, what else should I be looking at? I've got spark; gas is new; plugs are new and gapped; motor is 10 years old; owner is MUCH older and weary of chasing this problem! Any help is greatly appreciated.

sailingdog · #2 (**permalink**) 05-09-2007

Did you check the fuel filter and make sure it is clean? Also, have you checked the fuel line for leaks? If there is a pinhole in the fuel line, you'll have problems with the engine running properly.

Cruisingdad · #3 (**permalink**) 05-09-2007

Sounds similair to the problem I had on my Merc. It is a 6 hp 4stroke.

It would start fine and run fine without a load. Take off the choke or put a load on it and it would bog down, backfire, then quit. Problem got worse and worse. It was pretty new, so I could not see it being the carb... but it was.

Rebuild your carb. A few other tricks are to run your outboard dry EVERYTIME you are done for the day. I just pull the fuel supply off the motor as I get ready to hoist it on the davits. Only use fresh fuel and not last years leftover (which is difficult to throw out gas at todays prices).

Pull the plug and if it is really black, you are likely running rich. Clean it and re-gap.

SD mentioned checking the fuel filter. I have never had one clog up. I am not sure they are worth a crap as in my experience they never seem to catch anything.

I don't know if that helps, but that is what I would do. If that does not work, use it as an anchor and go buy a new outboard. Those lightweights are neat. Remember, it is a boat and it is expensive. Boating just would not be the same unless you spent lots of money to support it!!

- CD

Newport41 · #4 (**permalink**) 05-09-2007

The above posts are both good advice. I used to be a small engine mechanic and I can't stress how uninformed most people are about fuel for their outboards. "During Spring comissioning..." tells me all I need to know right there. Taking the carb apart and cleaning it with an appropriate solvent is the first step. A carb rebuild kit with new seals and diaphrams is also required, then I'de check the rest of the fule system.
I can not stress enough that at the end of a season or any peopriod of none use over three months you need to put some fuel stabalizer in the tank with whatever fuel is in there and then run the engine dry after that. If you're worried about wear on start up there are products for that too or put a drop or two of oil in the cylinder.

sailingdog · #5 (**permalink**) 05-09-2007

BTW, I installed a very small Racor water/fuel separator type filter for the Honda 20HP four-stroke that is the auxilliary engine on my boat. Not too expensive, and cheap insurance IMHO.