Honda 100 outboard

[stroker1]

I have an old Honda 100 (10 horse) outboard. I tried to get it running for the year, and I could not get it to idle. It would only run at high rpm's. When I would try to let off on the throttle, it would start to sputter occassionally backfiring. Occassionally it would run at idle with the a partial choke. <br />Any ideas????<br />I cleaned the fuel filter.

 

[radsrh]

Re: Honda 100 outboard

There was just a post of a Honda with the same symptoms, under sumerged 9.9 Honda stalls with choke in. After pulling the carbs twice and cleaning he got her running good, my sugestion is to pull the carb once and let soak and give a good cleaning paying special attention to the slow jet and give it a try.

 

[45_red]

Re: Honda 100 outboard

Clean the carb.s , check the plugs and points if it's old enough that it has points. Plugs are NGK dr5hs or dh4hs gap .025; points should just start to open when the F mark on the flywheel lines up with the index mark on the starter(rewind) case. That's 15% BTDC. Check both cylinders & get them equal.

 

[stroker1]

Re: Honda 100 outboard

Thanks for the advice. <br />After Soaking the carb for 1 day in a caustic solution, I rebuilt it with a new float, and jets.<br />Still no improvement. I then replaced the points and condenser. This gave some results, but I don't think I have the gap set right on the points. <br />When I get it started, the engine races to high speed, then idles down quickly and spuders and dies. Occasionally I can feather the throttle when it is idling down, then it will run at a fast idle for a while. But when I rev the engine, when it returns to idle, it spuders and dies.<br />I replaced the plugs and fuel filter. They do not make a new coil for this engine anymore.<br />What could it be???

 

[rickdb1boat]

Re: Honda 100 outboard

Still sounds like a carb problem. Did you set the float parallel with the carb body and blow out the carb with compressed air when you rebuilt it?

 

[stroker1]

Re: Honda 100 outboard

Can you elborate more on setting the float?

 

[stroker1]

Re: Honda 100 outboard

OK<br />I rebuilt the Carb. I Cleaned it throughly again and used compressed air to blow through all of the passages and Jets. I set the Float and Pilot Jet to the factory settings. I also replaced the points and condenser. Setting the points to the factory gap.<br />The engine fires up without a problem. It races to a high idle, but then idles down, spuders and Dies. It occasionally backfires out the carb? If I catch it while it idles down, I can usaully get it to run quite a while at a high idle.<br />Its almost Dealer time. I'm to give it one more try tonight. Anyone got any ideas.

 

[Yepblaze]

Re: Honda 100 outboard

Last Honda I did needed attention paid to the part above the main jet. Then there was the one that had a loosened manifold. Also had one that had an internal leak around the needle/seat that required a new carb complete. It would idle for a moment then sputter out from over rich.<br /><br />You also might want to make sure any carb manifold has not come loose from the block and that the valves have not become too tight or leaking.<br /><br />This might be of some help if you are so inclined to go over the carb again. web page

 

[stroker1]

Re: Honda 100 outboard

Thanks for all of the advice. I finally got it running well at idle. But, it will only idle for about 5 minutes, then die out. While idling, it smoked quite a bit. I opened the Oil fill cap, and when I got to the last thread, it blew off. There is alot of pressure building in the crankcase. I think this is why it is stalling out ofter five minutes. <br />Any ideas on what is causing this, and where should I start to fix it.

 

[Yepblaze]

Re: Honda 100 outboard

I don't have a manual or parts breakdown, but you need to find the crankcase breather if you feel the crankcase pressures are excessive.<br /><br />What operates the fuel pump on that motor? Is it crankcase pulse driven or? Perhaps if it's pulse driven you are on the right track or it might be suspect.

 

[stroker1]

Re: Honda 100 outboard

The Fuel pump is driven off of valve body. It is a pulse style fuel pump. How would this cause the excess pressure. I took the fuel pump apart, and everything looked great. The pulser part, is completely sealed from the internals of the engine.

 

[stroker1]

Re: Honda 100 outboard

Alright. I found the breather tube, and it was blocked. I cleared out the crap in the line, and started the engine. Smoke blew out from the breather at first, and got worse as the engine warmed up. Somewhere the engine is build up pressure in the crankcase. <br />Time for a Rebuild???

 

[Yepblaze]

Re: Honda 100 outboard

Now that you have cleared the breather tube that got all gunked up from blow by, (the escape of cylinder pressures past the piston into the crankcase), the fuel pump will probably work now. If, in fact it was crankcase pulse driven. The should cure the "runs out of gas in 5 minutes or so" thing. Although, even that could be iffy due to lack of negative pulses due to crankase pressurisation from the blow by.<br /><br />The issue of excessive blow by would be normally attributed to worn rings/piston/cylinder. Worn piston/rings/cylinder can manifest itself as poor running, starting, ect., ect. And as you see, plugging of the breather leading to it's own issues.<br /><br />Sounds like you want rebuild, replace, or just operate it as is.

 

[stroker1]

Re: Honda 100 outboard

Thanks for the comments. This Motor is a 1979 - With under 50 hours on it. It was used as a sailboat kicker for 2 years, then a kicker for a power boat on and off for the next 22. If fact it wasn't used at all for about 5 years.<br />I can't figure out why the rings would be worn. Unless it was from when I was trouble shooting and running the thing way to rich?? or Lean??<br />Again thanks for the advice.

 

[Yepblaze]

Re: Honda 100 outboard

Maybe the rings are just "stuck" from non use but it seems odd to see that. <br /><br />Did it get at least annual oil changes?<br /><br />Does it "use" oil?<br /><br />Of couse I may be wrong but........<br />Perhaps I've seen (maybe on more that one occasion) where Hondas of that size or vintage had had an issue with water ingestion into the crankcase. Not sure what search perameters you'd use to find it in the archive here though. Perhaps someone else recalls what "that" was about.<br /><br />Something like that could cause it.

 

[jim dozier]

Re: Honda 100 outboard

I agree with yepblaze, the source of crankcase pressure is piston blowby and/or a clogged crankcase ventilation system which you have apparently discovered. The pistons and rings probably aren't worn just stuck. Try some automotive "ring-free" type products you pour in the carb, and verify that you have completely unclogged the breather tube and ventilation system.<br /><br />Also check to make sure you don't have too much oil in it.

 

[stroker1]

Re: Honda 100 outboard

Thanks for everyones advice.<br />We basically put the motor on the back of the boat and ran it for a couple of hours.<br />After pushing a 25 ft. boat for 2 hours at almost full throttle (2.4mph), the motor is running great. It idles perfect, and starts one pull like it always used to. It still has a slight hesitation when accelerating, but I think that is a points gap issue that I can easily take care of. Blow bye out the vent is minimal now.<br />Again thanks for all of your advice.<br />I need to put more hours on this thing. Its primary use is a backup for the main, and trolling once and a while.

 

[jim dozier]

Re: Honda 100 outboard

I believe that boat motors, especially marine use, will live longer if you use them than if you don't.