What's this Gen 1.2 odd ignition or fuel problem?

[syscrusher]

I started the bike and ran it for only a few minutes each time then installed all new plugs and started it and let it warm up for a while. I then rode it back into the garage so that I could also pull a car in alongside it. The choke was off completely now but when I tried to rev the engine it wouldn't go and acted flooded, more throttle = less RPMs. I turned it off, trying to think why it was acting this way. I'm not sure it works with CV carbs but I tried opening the throttle and holding it to clear the carbs. I could not get it restarted and decided to just leave it. It seemed like the battery could be low so I put the charger on it over the weekend. Today I thought I would be lucky so I tried to start it and it wouldn't kick off again. It had one bar for gas but I added a gallon from the mower can anyway. Still wouldn't start. I fiddled with the ON/OFF/RES knob turned and then back to ON and then it would start and run. Rode it to the gas station and put 2.5 gallons in it to fill it. What is going on with this? It was down only 3.5 gallons but that was enough to keep it from running? Does the battery have to be at peak charge to run these?

Edited August 20, 2013 by syscrusher
fixing

[Trader]

Give it a good heavy dose of seafoam. Today's gas is so bad these bikes tend to plug up.

 

I put in a few ounces every 2nd or 3rd tank.

If you are going to let the bike sit for any length of time (2 weeks) or more you should put stabilizer in it and even better, find NON ethanal gas.

 

The ethanol breaks down and leaves a waxy residue that can plug the carbs. Up here about the only ethanol free gas is premium...so that's what I use if it's going to sit.

 

You might think about changing the fuel filter....or if the bike was sitting for awhile you could have crud in the tank.

[Peder_y2k]

Suspecting a fuel delivery problem. Could be anything from debris in the fuel tank to deteriorating fuel lines, blocked filter, or even a failing fuel pump. Need more info from simple tests such as flow rate from fuel hose where it connects to carbs, with ign. turned on for pump to work. May need to cycle ign. switch on-off-on a few times (not cranking) to observe fuel flow to determine if flow rate is normal.

If the fuel level inside the carbs is not correct, the engine won't start.

-Pete, in Tacoma WA USA

[Marcarl]

If you are down to one bar, chances are your fuel pump won't be getting any fuel and it will quit while just sitting there running.

Also, these bikes won't start very well if at all with the throttle open. The choke is not a butterfly as one would normally think, but rather it's an enricher valve, so the system works differently, and opening the throttle doesn't seem to help the starting.

[syscrusher]

If you are down to one bar, chances are your fuel pump won't be getting any fuel and it will quit while just sitting there running.

Also, these bikes won't start very well if at all with the throttle open. The choke is not a butterfly as one would normally think, but rather it's an enricher valve, so the system works differently, and opening the throttle doesn't seem to help the starting.

 

It was only on a very slight incline with the front of the bike a little higher than the rear and it only took 3.5 gals from one bar to fill. Worries me what it would be like climbing mountain switchbacks with it then.

[MiCarl]

My 89 only takes about 3.5 gallons when it reads empty. It still runs when the gauge reads E even without switching to RES.

 

My guess would be debris in the tank, partially clogged fuel filter or failing fuel pump which need the extra head of more fuel in the tank to flow enough to the carburetors.

 

Replace the fuel filter. While you have it off make sure you get lots of flow from the line at ON and RES.

 

I wouldn't be surprised if you also need to go through the carburetors.

[bongobobny]

When you mentioned fiddling with your fuel cutoff switch I'm betting you have crud in your tank and the petcock is also filled. You will probably have to drain, clean, and coat your tank, and replace the petcock. I'll bet when you remove your petcock you will find it deteriorated...

[frankd]

Do you have the fuel tank petcock in ON or RESERVE? I leave mine in RESERVE and rely on the gas gauge. That way, the bike will use all 5.3 gallons in the tank without the problem of running out of gas at a bad time. Using the whole tank, I can run over 200 miles if I want to. When the last bar goes out, mine takes 3.9 gallons. Then I look at the mileage on the odometer and buy gas within the next 50 miles.

[Bob Myers]

Do you have the fuel tank petcock in ON or RESERVE? I leave mine in RESERVE and rely on the gas gauge. That way, the bike will use all 5.3 gallons in the tank without the problem of running out of gas at a bad time. Using the whole tank, I can run over 200 miles if I want to. When the last bar goes out, mine takes 3.9 gallons. Then I look at the mileage on the odometer and buy gas within the next 50 miles.

So, Frank are you saying that your bike still has over a gallon in the tank, without going to reserve after the red light comes on? I've never pushed my luck, always fuel withing 5 or less miles after light comeson.

[syscrusher]

Do you have the fuel tank petcock in ON or RESERVE? I leave mine in RESERVE and rely on the gas gauge. That way, the bike will use all 5.3 gallons in the tank without the problem of running out of gas at a bad time. Using the whole tank, I can run over 200 miles if I want to. When the last bar goes out, mine takes 3.9 gallons. Then I look at the mileage on the odometer and buy gas within the next 50 miles.

 

It's ON. With your method when it's done you've got to walk for gas. I'm used to that with my fuel injected bike but I prefer the soft landing of keeping a reserve of fuel since the bike allows it.

[GeorgeS]

Run it down to almost reserve. Then completely drain the tank, you might have water or crude in bottom of tank, Drain it at the petcock, Flush it.

Put in all new fuel, and some Sea-Foam, or some brand of fuel injector cleaner.

I would also drain each of the carb bowls seperatly, each one has a drain valve, and a drain hose.

 

Also you might need to replace the fuel filter,

[frankd]

Yes, you have over a gallon of gas left when the last bar goes out and the red light comes on. On my 83, if you stop for gas immediately after the red light comes on, it takes 4.0 gallons. My 89 takes 3.9 gallons. That leaves about 1.4 gallons left in the tank. At 40MPG, that's 56 miles. Now if you're going 80MPH and getting lower gas mileage, you can't push it that far or you'll be walking. You can also estimate your gas mileage by when the bars on the display go out (if you are riding on level ground). I know that the last bar goes out on my 89 @ 3.9 gallons. If I have 170 miles on that tank, I'm getting about 43MPG. I know @ 200 miles, I'll still be running.