It's combo of non-running/missing

The long version of story:
bought the bike after the owner had to put plugs in it to get it to run, took it for test ride and it wouldn't stay running at idle, otherwise seemed running ok.
Bike apprently has been sitting since fall. Due to circumstances had to leave the bike with him for 2 weeks. He ran it onto my trailer when I picked it up. When I unloaded it and started it up it would only run on one cyl, with an occasional "hit" on the other one.
(Yes, I suspect he was riding it around, fouled the plug, then was too lazy to change it and consealed it by making sure he ran it onto trailer.)


I'm going with it's the 6mo+ old gas for a first try, before looking at ign.

It seems like the only way to drain the tank is to pump fuel out using the return line?

Instead of NGK can I use Autolite without effect?

Would it hurt to run one step hotter plugs? (in town)

Do the plugs really need changing every 8k miles?

Do the bikes seem to have weakness(es) in ign system?

Is the FI indicator reliable in telling you if there is a problem/diagnosing problem?

(I'm trying to think of all of these up front because u guys

Your on the right track, drain all the fuel you can out of the tank. I would suggest a hand operated pump to get the fuel out.
I would then add fresh fuel and if you can find it no ethanol. I would also add Seafoam fuel treatment, two oz. per gallon and take it out for a very long ride at 45 to 50 MPH. Change the oil and filter, not so much because it's not running correctly but more because you don't have any idea when and if it's been changed recently.
As far as the plugs go, I'd use NGK with the recommended heat range. You can also use the Irudium SP? plugs if you like as they do last longer and have a slightly hotter spark.
My guess is your injectors are gummed up with old fuel residue and Ethanol contamination. I only run non-ethanol fuel in all of my two wheeled vehicles, you may not be able to find it in your area though. I have to pay 10-15 cents more per gallon but I get better mileage and don't have to worry about the damage that ethanol can cause.
I don't believe that the ignition systems for our machines have any serious problems other than often times we let our Swings set for weeks or months without running. The fuel tends to get gummy and evaporates in time leaving a residue.

Gary

How old is the scooter? You may have a problem with the fuel pressure regulator.

When a scooter sets for a while the F.I. Fuel Pressure Regulator goes bad. It's located on the top of the engine. You will need to remove your seat and the top cover to replace it. This happens allot on this bike when they set for a long period.

stanly wrote:

It seems like the only way to drain the tank is to pump fuel out using the return line? Yes, or syphon

Instead of NGK can I use Autolite without effect? No

Would it hurt to run one step hotter plugs? (in town) Yes

Do the plugs really need changing every 8k miles? Yes

Do the bikes seem to have weakness(es) in ign system? No

Is the FI indicator reliable in telling you if there is a problem/diagnosing problem? No

You may not even have a gasoline problem. You could have a pinhole leak in your fuel pressure regulator.

stanly, you don't have your location in your profile, the US is a big country.
Someone may be close enough to offer a hand. Gary gave you a lot of good information to start with. I know here in Florida non-ethanol fuel is easy to find and is a good place to start. After giving his information a try let us know how you make out. Good luck, it's a Honda (what year?) you will get it going.

ScootRGuy wrote:

Your on the right track, drain all the fuel you can out of the tank. I would suggest a hand operated pump to get the fuel out.
I would then add fresh fuel and if you can find it no ethanol. I would also add Seafoam fuel treatment, two oz. per gallon and take it out for a very long ride at 45 to 50 MPH. Change the oil and filter, not so much because it's not running correctly but more because you don't have any idea when and if it's been changed recently.
As far as the plugs go, I'd use NGK with the recommended heat range. You can also use the Irudium SP? plugs if you like as they do last longer and have a slightly hotter spark.
My guess is your injectors are gummed up with old fuel residue and Ethanol contamination. I only run non-ethanol fuel in all of my two wheeled vehicles, you may not be able to find it in your area though. I have to pay 10-15 cents more per gallon but I get better mileage and don't have to worry about the damage that ethanol can cause.
I don't believe that the ignition systems for our machines have any serious problems other than often times we let our Swings set for weeks or months without running. The fuel tends to get gummy and evaporates in time leaving a residue.

Gary

Handcranked, that's so much better idea.
If it's on schedule it was recent oil change and it looks clean (I'll look in back of owners manual)
I wouldn't even know where to look for non-ethanol

model28a wrote:

stanly, you don't have your location in your profile, the US is a big country.
Someone may be close enough to offer a hand. Gary gave you a lot of good information to start with. I know here in Florida non-ethanol fuel is easy to find and is a good place to start. After giving his information a try let us know how you make out. Good luck, it's a Honda (what year?) you will get it going.

guess closer location might help(updated profile)
2002 Silverwing (black)
I'll get some pic up when we get to the "you will get it going." stage.

2002? Then I'd suspect the fuel pressure regulator.

If you want trouble just use the eth. additives that are in the fuel today. If you can stay away from those your Swing will usually be pretty trouble free as far as fuels are concerned. This is especially true if you are going to store or not run the Swing for "long" periods of time.

CR9EH-9plugs were installed by the po while I stood there waiting on him. Guess now I know one reason they fouled, too bad all I could find is Autolite-guess no matter how bad they are at least correct range.

rollsroyce250-hope that's not it as I would have to buy gauge to test.

stanly wrote:

rollsroyce250-hope that's not it as I would have to buy gauge to test.

A vacuum gauge is not necessary to troubleshoot the fuel pressure regulator. There are 2 ways to diagnose. Pull the plugs after letting the engine idle for a few minutes. If they're fuel soaked, your regulator is shot. The other method is to pull the vacuum hose leading to the regulator after the engine is shut off. If there's any sign of fuel in the hose, your regulator is shot.

Pumped out the old gas and refilled with 2gal of fresh gas and Seafoam.
Today is the day. That 40mi ride idea is going to be going around a loop near my place about 3-4 times (about 10mi probably), then maybe something longer.

Ok, went on my loop ride:
Started fine, went to cold idle speed, dropped to normal 1000rpm when it warmed up.
Went out, ran about 10mi, when I turned around it was idling 900-700, at 13mi I stopped in an intersection and it stated missing and died.
Rest of the way home I had to hold the throttle cracked to keep it running.

Thinking rollsroyce250 called it.
I'll let it sit in back yard and idle, then check plugs.
guessing removing the cover under the seat won't give me enough space to work on this, maybe not even see it?
Tips on getting to the regulator to work on it?
Thinking I'll have to remove the "pedestal" under the seat to get to reg.

YES! I've put on about 50 around town miles and runs much better, but still seems like there is slight missing at idle and vibration between 30-40mph.
Thinking I won't worry about the miss prob untill after I've run at hwy speed for couple hrs.

Your idle rpm should be 1300 rpm when warmed up .Adjust your throttle screw or the cable adjustment at the handle bar throttle .

tinman wrote:

Your idle rpm should be 1300 rpm when warmed up .Adjust your throttle screw or the cable adjustment at the handle bar throttle .

Bad advice. The ONLY place to make an idle adjustment is the idle adjustment screw on the throttle body housing. The cable adjustment on the twistgrip is ONLY to get the correct slack in the cable.

Be careful when accessing the idle adjustment screw thro' the hole under the seat, it's very easy to dislodge one of the many small pipes in there. DAHMIK !!

bikerboy wrote:

Be careful when accessing the idle adjustment screw thro' the hole under the seat, it's very easy to dislodge one of the many small pipes in there. DAHMIK !!

As well as turning the wrong screw. There is 1 idle speed adjustment screw and 2 throttle plate synchronization screws.

Throttle Operation Page3-4
Measure the free play at throttle grip 2-6 mm (1/16 to 1/4 .Minor adjustments are made with the upper adjuster.Major adjustment are made with lower adjuster.
Engine idle speed PG 3-13
Idle speed adjust, after all other engine maintenance items have been preform and are within specification .Warm up engine and turn throttle stop screw to 1300 rpm only after fuel injector cleaner has been run to clean ant varnish residue has run through or rpm could rise to much and the clutch bell will not disengage . Most likely the rpm was set right and the fuel has to clean it's self out. Ruff idling give you a clue. If low idling does not correct it self adjust idle screw.

Cenex has non ethanol