Running on 1 Cylinder

[Guest]

Hi again. I was messing with my suzuki and notice done of the plug wires was off while it was idling I plugged it back on and no difference in anything.

So I started to unplug the spark plugs 1 by 1 and finally it stalled when I hit cyl #3.

The exhaust pipes all get hot while idling. Could my carb sync gauges have been off? What could I do?

The spark plugs all spark. I did check with a spark tested but none sparked with the spark tetser.

What should I do?

[curtie94]

Just wondering could it be the air box? If I put a rag in front of the inlet I get immidate throttle response.

I did go through and seal my air box last year. But I did notice that the tops all seal on the air box side. But the bottom of the two middle carbs is off.

Are there any tricks to getting the air box on the carbs evenly?

[Steve]

Hi again. I was messing with my suzuki ...

I was going to ask for some kind of clue, then noticed you only had one Suzuki mentioned in your sig.
Thanks for putting it there, that is exactly why we ask you to do it.

So I started to unplug the spark plugs 1 by 1 and finally it stalled when I hit cyl #3.

Which way are you numbering your cylinders?
#1 is on the left, under your clutch hand, #4 is on the right, under your throttle hand.
I ask this because if you are numbering them backward, and forgot to plug the vacuum line on #2 when you synched the carbs, it's sync setting would be WAAYYY off.

The exhaust pipes all get hot while idling. Could my carb sync gauges have been off? What could I do?

More likely a forgotten vacuum port, as previously mentioned, but, just for the record, what sync gauges are you using?

Just wondering could it be the air box? If I put a rag in front of the inlet I get immidate throttle response.

I did go through and seal my air box last year. But I did notice that the tops all seal on the air box side. But the bottom of the two middle carbs is off.

Are there any tricks to getting the air box on the carbs evenly?

Sounds like you have a MAJOR air leak at the carb inlets. The only "trick" is to get new boots from the airbox to the carbs. The old boots have shrunk a bit and gotten hard, so they don't fit as well. You will be amazed at how much difference there is with new boots.

.

[curtie94]

I am numbering them from left to right like you said. The vacuum gauges are actually a factory Honda carb sync tool.

I managed to get the air box to fit better but still not perfect.

I'll get ahold of a carb sync tool again and just check everything out.

BTW what cylinder is not adjustable?

I'll look into it and write back.

[tom203]

Number 3 is the master! How's the weather- almost 30 degrees here.

[chef1366]

Bench sync them first. Make sure all the butterflies are open at the same time with #3. I use a paperclip without sharp edges. Open the main idle knob until you can slip the paperclip under the #3 and make the others the same.
As mentioned replace the O-rings behind the intake boots and replace all the airbox boots. You will thank me with the ease of installation and they will seal. It's a win win.

[curtie94]

We hit 45F today not a bad spring day, but tomorrow will only be 12F.

Back to the bike I removed the carbs and bench synced them. I used a heat gun on the air box boots and it made my life so much easier.

I got it all back together and no change.

I did notice that cylinder 4 wasnt firing but all the others were. I checked spark and it was good the plug was soaked from the choke so it was getting fuel. I opened the butterfly with the adjustment and the rpm started to rise. I still need to set the tank back up so I can see how it runs, I will also re-sync the carbs. hopefully I can figure this out before we get really nice weather. LOL

[tom203]

I'm sure this has been asked but.... You sure the mixture screw tips are ok ?

[curtie94]

Last I checked yes they where OK.

I'll pull them out tonight and check though just to be sure.

By the way does anyone know the thread pitch for the fuel screws.

The threads in one of my carb bodies is all screwed up. So it would be nice to clean them up.

[gustovh]

Time to check the valves.

V

[curtie94]

I set the valves when I replaced the head gasket. Not even 10 miles ago.

Valve timing is also spot on.

[chef1366]

How is the compression on #4?

[curtie94]

I can check to be sure but last time I checked it was around 140psi. Just like the rest of them.

[curtie94]

I just checked compression.

Cyl 1: 125psi
Cyl 2: 125psi
Cyl 3: 125psi
Cyl 4: 130psi.

So compression is a bit lower then I thought but they are all generally the same.

I was idling the bike and noticed a lot of smoke coming out of the right hand exhaust pipe. The left pipe had practically nothing.

So I pulled the plugs and noticed cyl 4 plug was wet. The rest where dry but dark.

I'll get ahold of the carb sync tool tomorrow and set them again.

But what would cause the smoke? Stuck float? Float set too rich? I tried adjusting the fuel screw and not much seemed to happen

[chef1366]

Well with that compression which is good you should be pulling fuel.
Either sync which you proved by opening the butterfly while it was running or a clogged pilot circuit.
Oh and if you have a wet plug you're getting gas so that means you need to either get a new spark plug cap or check the connection on the current one.