[gymjunkie]

Last summer when I was working on getting it running I ended up pulling the plugs out and noticed they were shiny black so I wiped them off with a rag and put them back in and I was able to start the bike and it sounded like it ran just fine. The next day I tried to start it again and I came across the same problem so I checked the plugs and they were shiny black again. Am I running too rich? how do I solve this problem? I have a 1983 Honda Nighthawk 650

 

[Critter]

Running way to rich.

What bike and what has been done to it?

 

[gymjunkie]

1983 Honda Nighthawk 650. Not a whole lot has been done to it yet really as I don't know a whole lot. I rebuilt the petcock a couple years ago because it was leaking and my cousin helped me take the carbs off and cleaned them out. The bike started running after we cleaned them out this was a couple years ago though and obviously need it fixed rather than cleaned lol

 

[Dodsfall]

Did the motorcycle sit in storage with untreated fuel in it for any length of time?

 

[gymjunkie]

I always cut off the gas and ran the carbs dry. Last fall i left gas in the tank but still ran the carbs dry

 

[gymjunkie]

But yes the fuel was untreated

 

[Dodsfall]

My guess is gunked up carbs. Next season it would be a good idea to stabilize the fuel before storage, leave treated fuel in the carbs, and avoid the problem altogether.

 

[gymjunkie]

I'll keep that in mind. What should I do now though to fix it running too rich? I'll get the carbs pulled and cleaned tomorrow if I can find time. Here is a pic BTW of one of the plugs.

 

[hogcowboy]

Hold it. How long are you riding before you pull these plugs and look? If you are just starting and stopping you won't learn anything from the plugs. You got to put 20 miles or 20 minutes or the like on them.

 

[gymjunkie]

Well I learned right away that they blackened up quick. I had the bike running maybe 15 minutes, revving it up during but it wasn't being ridden just sitting on the center stand.

 

[hogcowboy]

You are probably right that you are running rich but would you be shocked if you ran it on the road at 60mph for 20 minutes if they were just brown? It is possible. Just starting and rev'ing doesn't tell much reading plugs.

 

[gymjunkie]

I get what you're saying. I can't do anything though until I figure out where to start because it won't start.

 

[gymjunkie]

So where do I start in getting this thing permanently running?

 

[Eye_m_no_angel]

Where the plugs wet and drippy black, or dry sooty and black?

 

[gymjunkie]

Where the plugs wet and drippy black, or dry sooty and black?

Pretty sure they were dry but I do remember them being very shiny black, if that helps any. I really hope you're not thinking what I think you're thinking (oil rings)

 

[gymjunkie]

Now that I think more on it they were definitely dry sooty

 

[85dirty]

check your air filter to see if it is dirty, if that's not the case then check the float heights.

 

[gymjunkie]

How do I know the right height and how do I adjust it? My mechanic neighbor took a quick look and he said he didn't see how they would be adjustable. And tbh I'm not seeing any way either.

 

[gymjunkie]

I just watched a video on a guy explaining how to do the adjustment but he is describing it on a float that has metal in between them, mine is all plastic so obviously I don't want to try bending anything like he was.

Oh and the air filter isn't bad yet

 

[slumlord]

I always cut off the gas and ran the carbs dry. Last fall i left gas in the tank but still ran the carbs dry

Well you probably want the simple and low cost stuff first, no?

First, get rid of that old gas in the tank, and that also includes using the drains at the bottom of the carb bowls. A little more on this to emphasize a point. I have a CB750 that runs perfectly, but if gas sits in the carb bowls for much more than a week, it is very difficult to start because the gas degrades. I just drain some gas thru the bowl drains and the fresher stuff in the tank starts it instantly. Not all bikes are like that, but you never know for sure how yours is until you try things like this.
Second, buy some new spark plugs and make sure that they are correct for your bike and have the correct gap. Matching the ones presently installed might not be the thing to do if the previoius owner had not installed the correct plugs previously.
Third, make sure that your idle circuit adjustment screw is set correctly for EACH carb and using the Honda manual is a good idea. As a quick cheat, I have often tightened and then returned the individual carb idle adjustment screw a half turn and then placed it back where it was. What often happens is that action cleans the needle tip of the adjusting screw a bit and then the bike runs.
I agree with HC when he says idling a bike will not tell the true story. There is a procedure called a plug chop to get the true condition of the situation