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2005 Honda 20HP starting issue

L

lotwtrout1

New member
Hello - first post here.
I'm working on this outboard and really at a roadblock. Initially, I pulled the carb to give it a cleaning and found there was some "goop" in the bowl. not the green varnish type stuff but almost like a jelly. gave the carb a thorough cleaning and installed a new gasket set. Could not get the engine to start - not even a sputter.
Found out there was water in the tank... like a lot of water! I removed the hose and pumped out the fuel from the lines and flushed with fresh good fuel.
Still would not start.
I removed and recleaned the carb about 6 times and I'm sure every passage is clear. the plunger in the bowl shoots fluid up the bowl passage when depressing with a screwdriver. the main nozzle and jet set are clean (can see light through all the tiny holes). removed the idle mixture screw and cleaned through there. all other passages on the main body. and still will not fire up.
I did get it to run by cheating and covering about 3/4 of the carb throat with a rag and it would run about 1/4 throttle that way but as soon as the rag is moved it dies.
So is this carb still plugged up somewhere? is it possible that the carb is cracked internally from sitting over a cold Canadian winter with water in it? is it actually deeper than all this and a vacuum issue where it doesn't have enough vacuum draw to pull fuel through the carb?

all thoughts would be appreciated as I'm at a loss right now.
 
Hi,
Is this a manual choke model or electric start with auto choke?
Probably doesn't much matter really but I would like to know.

My guess is that the carb is ok and just needs "mother's touch" getting it cleaned properly. I say that because I've done a bunch of these and people are are calling me a mother.

One of the things that really affects how this carb works and most first timers miss is getting the the accelerator pump circuit cleared out.
If it's just slightly plugged, the engine won't run. I believe that's the "plunger" you mentioned.

If you didn't force cleaner or compressed air out of the spray nozzle located on the end of the brass tube that juts out horizontally into the front of the carb throat, that may be the issue.

What I do is remove the float bowl and locate the feed passage for the brass tube in the main body. Then, prop the throttle plate wide open by gently wedging a pocket screwdriver into the linkage to hold it open.

Spray carb or brake cleaner into the passage using the little plastic straw that comes with the can. If the nozzle is clear then a stream of cleaner will shoot about 8 feet out of the back of the carb. Yes, 8 feet.

If not, you have some work to do. You need to insert the plastic straw into the rear of the carb throat and carefully place the end over the nozzle hole at the end of the brass tube and do what I call "backflushing".

You have to force some fluid backwards through that nozzle.

It can be a pain getting the straw end directly on the nozzle but it has to be done. If you can get just a dribble of cleaner to come out of the entrance of that feed channel, then you can put the straw in the feed channel and try to force fluid from the nozzle again. Even a little dribble coming out means you're making progress and it won't be long before you're finished.
Go back and forth like that until you get an 8 foot stream shooting out the back of the carb. Just DON'T put your eye out! ;>)

I have other little tips but first let me know how that exercise goes. Don't worry, you'll get it going.

Good luck.
 
Well, as long as "very good stream" stands for 8 foot stream, then ok.

I take it you replaced the small oring at the top of the jet-set. I hope you lubed it and inserted the tube very carefully because that oring is critical and very easy to damage during install.

The same goes for the oring on the idle screw.

Back to backflushing.
It is important to ensure all the fuel orifices at the top of the back of the carb throat are clear. In this particular case the idle circuit is most suspect because your condition screams lean at start up. That circuit may not be delivering fuel. Again, when I have the carb off, the jet-set off and the idle valve out I place the end of the straw over each orifice and backflush each circuit to make dang sure there's good flow from each one.

On the mounting flange at the front of the carb are the two air jet passages. High speed and low speed. It's good to first block the idle needle hole and the jet-set hole with your thumb and finger and see that you get flow from the low speed air jet while backflushing the idle orifice. You can't get a great seal doing that but it's enough. It ain't easy and you have to hold your tongue just right but it can be done.

Then do the same for the high speed air jet while blasting the transition and high speed orifices. Then put the straw in the entrance of both and blast them while sealing the jet-set and idle needle valve holes with your fingers. You'll probably need to switch hands. Fluid should spray from each delivery orifice at the top of the carb throat.

That guarantees good fuel delivery through the main body.

Are the two vents clear? I don't think a plugged one would cause this kind of no start but just checking things off.

Something else to look for is mud in the accelerator pump feed tunnel in the carb bowl as well as the drain passage. You might need to dig in them with a piece of wire.

I know you said that you looked at it carefully but double check that there isn't a hairline vertical crack in the jet-set tube. I had so much trouble with those tubes when I was doing "production line' carb work I just kept them in stock and put in a new one every time. They suck!

While it's possible that the lean condition is due to a vacuum leak, I highly doubt it on this engine. Especially since you say you replaced the gaskets. But if you suspect it, simply hose it with carb spray with full choke. It should briefly fire and, often, you can see the spray get sucked in at the leak if you have a helper pulling it over for you.

With all the water you say that you found I do suppose a freeze could have caused damage there. But I'm a SoCal boy and I don't know about such things.

That's about all I can think of carb wise. Hope it's not some strange weak spark gremlin or super low compression causing your misery. But you got it to run so I doubt that.
 
I bought the gasket set that came with the new rubber o-rings for the jet set, idle mix screw and the bowl drain screw, that said i've had them on off so many times now i hope i didn't cut one. I may see about getting a new jet set and see if that works.... i had read previously that it could crack and be hard to see and i really looked as close as my eyes could see and no crack - but maybe it is.
I do have a buddy with an ultrasonic cleaner, so may take it off once again and bring it to him for a soak and see if maybe that might help.
I've done all the "normal" stuff and just not sure where to turn next. the fact it ran (albeit with a rag covering mist of the carb throat so that it actually drew fuel), is encouraging... frustration thing this one is.
 
Have you verified that the cam timing is ok and the belt is tight?
Just thinking out loud about what else it could be besides the carb.

It won't hurt to throw it in the ultrasonic but I have two of those thing...one a very good one...and I guarantee that my "mother's manual method" of getting these things cleaned is more effective. BTDT.

Also a good idea to just sh!tcan the jet-set tube and install a new one. You could use the old to make a lapel pin or brooch.

Go back and verify you didn't pinch the idle oring and that the accelerator pump tube shoots the monster stream.

That engine will start and idle fine even if the accelerator pump piston is stuck or even missing. I have run them without the piston many times when parts were scarce.
Heck, I bet your little check ball at the bottom of the bore is already loose or missing. Won't make any difference....the engine will run just fine without it.

But if that tube nozzle is plugged ....even a little....it will drive you nutz.

I hope you get it sorted out.
 
Will double check the cam timing and belt tension. getting the carb into the bath tonight.
Honda dealer here is pretty good (the fella has been around for over 40years)... mentioned my issue to him and he also agrees its a carb issue. He hasn't seen a jet set go bad though - he never even stocks them and maybe sells one ever 4-5 years. not saying that isn't the issue still. I gave the jet set a very light polish with a cloth and it shined right up and I still cannot see any cracks at all.
one thing I'm curious about is the orientation of the jet set and main nozzle? is there any specific direction they need to face? they don't seem to be index'd at all but the holes in them lead me to believe there may be a need to have them in there a certain way?

When i took the carb apart last night (again), i inspected the o-rings that i had replaced and the jet set one does look slightly torn/worn and bowl gsk is getting deformed already, so for $20 i'm just getting another gsk set.

will hopefully be back on it tomorrow night. If all fails i'll just order the jet set - since it will take a week to get in and i'm away for work all next week then it is perfect timing to get it once i return.

I appreciate your input on this!
 
Hi,
No, there's no particular "hole orientation" to worry about with the main emulsion or low speed emulsion (jet-set) tubes with each other or the main jet.

As far as someone else never finding a bad jet-set I will simply say "well bless his heart!" Even the Honda Marine Carburetion Manual gives cracks in the jet-set tube an honorable mention so he's leading a charmed life.

Good luck.
 
I got this all fixed up last night. It went for a 2 hour bath in a professional ultrasonic cleaner at my buddies shop. installed a new gasket set and she fired right up! by far the most frustrating carb I've ever had to clean lol. thanks for the tips!
 
Well, you're the second one in the last year that said the ultrasonic cleaner did the trick so maybe they're making them more efficient these days. What solution did you use so I can pass that on?

Congratulations on getting her going.
 
The one used was at a small engine repair shop - so I'm not sure what they use for solution... I do know that he has great success rates cleaning small carbs this way.
 
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