20 HP Honda - Cold Start Issues

VForce

Cadet
Joined
Jun 7, 2008
Messages
13
Just purchased a new to me 2006 20HP 4 stroke Honda elec start - I am told it has about 15 hrs on it. It will turn over but not start on a cold start. Give it a touch of starting fluid in the air inlet and it will fire right up - though it will be rough for 20 seconds or so. After that it runs great until I turn it off and let it sit for 15 minutes and it needs another hit of starting fluid.
The spark plugs are a little varnished, and I have a new set ordered - but I am thinking that isnt the problem considering it starts fine when warm. Do these symptoms point to an electric choke issue or gummed up carb? Thanks for any ideas to pursue.
 

hondon

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Jun 11, 2001
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1,922
Re: 20 HP Honda - Cold Start Issues

It would be great to know what the idle speed is set at.If you are idleing to slowly you will get these syptoms.Idle should be as close to 900 as possible and you should be propped to maintain that on your boat when in gear.Also,do'nt do anything with the twist grip or remote on a cold start.It needs to be completely relaxed or you are defeating the enrichener.
 

VForce

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Jun 7, 2008
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Re: 20 HP Honda - Cold Start Issues

Wow, that is interesting. I had thought the idle RPM seemed a little low on this motor, but did not figure it could lead to a hard start. I will have to hook up a tach and see where its at. Also, I am guilty of giving the remote idle control a few pumps at first when it wont fire. I will try and run it tonite without giving it throttle. I guess I had gotten used to giving all sorts of throttle to my old 70hp 2 cycle to get it running. Gotta get used to 4 cycle O/B's. Thanks
 
Joined
Apr 29, 2007
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Re: 20 HP Honda - Cold Start Issues

Have been haveing same problems with my 20. Returned to dealer on a recall to install a new part on the fuel system. Seemed to start a little easier, but have not used it too much yet.

You may want to check with a dealer reguarding recalls. Take care,
ng
 

hondon

Lieutenant Commander
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Jun 11, 2001
Messages
1,922
Re: 20 HP Honda - Cold Start Issues

Remember ,when you set that tach ,that these things fire like a two stroke so do'nt flip out if you get numbers that do'nt correspond with your ears if you are useing a coventional auto tach.Just divide that number in half and you should be good.It can get confuseing depending on the tach you are useing.On these little guys I use a chainsaw tach.Works great.
 
Joined
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Re: 20 HP Honda - Cold Start Issues

The recall was for the "Fuel Chamber Kit"
Honda part number: 06168-Z41-307

Seems the origional part could alow fuel to leak inside the housing. Hope this is of some help.
ng
 

VForce

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Re: 20 HP Honda - Cold Start Issues

Seems as if my new to me 2006 BF20D honda has not had the recall perfomed yet to replace the plastic 'fuel chamber'. Gotta get it done. Can anyone tell me what function this part plays in engine operation? I cant figure that out. Maybe a fuel pressure regulator? This is tied into the fuel pump and carb with fuel hose,and on my engine sits just below the engine oil dipstick. Service manual is still on order. PS: NG, thanks for your earlier PM and help.
 

eipeldau

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Joined
May 11, 2007
Messages
49
Re: 20 HP Honda - Cold Start Issues

Hello VForce,

You don't want the cold fuel to reach directly the warm carburetor. This would cause unwanted vaporization and trouble. The fuel chamber gives the fuel the chance to reach an inbetween temperature, minimizing vaporization.
However, I believe that's not your problem, even if you have the old chamber.
I also have a 20hp and I had trouble in cold starts. After trying many things, I found out the enrichment circuit(which acts in cold starts) came obstructed from factory. The Japanese must have test-started the engine and forgot to drain the carburetor. I'd suggest to you opening the carburetor and checking that circuit, especially.

Good luck!

Henrique
 

VForce

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Re: 20 HP Honda - Cold Start Issues

Hello and thanks Henrique for that explanation. While researching thru this forum yesterday, I came across a previous post you had made concerning the clogged enrichment circuit on your O/B. Seems as that is the only plausible item left, considering how well the engine runs after it is warmed up.
I did some checking as suggested earlier and the idle RPM turned out to be right on, and I left the remote control alone while attempting to start. I am going to take the carb apart this week and ungunk it. Thanks everyone for your help.
 

eipeldau

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May 11, 2007
Messages
49
Re: 20 HP Honda - Cold Start Issues

Here's a hint, VForce:
After ungunking the circuit, take as a habit running the engine with the hose disconnected, until it dies. Then, drain the remaining fuel from the carburetor, using the drain screw underneath it. I know it's a pain doing it every time you leave the boat. But it's the only way I found for preventing the problem from arising again.

Henrique
 
Joined
Apr 29, 2007
Messages
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Re: 20 HP Honda - Cold Start Issues

Just an update.

Have had the motor out a number of times and there are no further problems with starting since recall was done on the fuel system.
ng
 

Lonestargumby62

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Aug 26, 2009
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Re: 20 HP Honda - Cold Start Issues

Henrique,
I've got similar problems with a 30hp Johnson, purchased new in 2002. I think I am going to have the shop look at the enrichment circuit as you suggested and/or begin draining the fuel after each use. This cold-start issue is so frustrating, and evidently not limited to Johnson or Honda outboards.
Thank you for your post.
 

eipeldau

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Joined
May 11, 2007
Messages
49
Re: 20 HP Honda - Cold Start Issues

Henrique,
I've got similar problems with a 30hp Johnson, purchased new in 2002. I think I am going to have the shop look at the enrichment circuit as you suggested and/or begin draining the fuel after each use. This cold-start issue is so frustrating, and evidently not limited to Johnson or Honda outboards.
Thank you for your post.

I wish these new carbs just had the good old butterfly-style chokes. The butterfly, when closed, makes a vaccuum and gas is sucked from the relatively clog-free main circuit. Actually, that's what I simulate when my fragile enrichment circuit doesn't work well: I partially obstruct the air intake with my hand. It works really well. You just have to balance the crack between your fingers for the right amount of vaccuum. I hope this hint can help you sometime!
Henrique
 
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