Starting problem

rock_rebel · July 11, 2010, 09:54:59 AM

Yesterday I put a half tank oh gas in my bike. When I opened the choke to let it idle for a while, the bike wouldn't start by pressing on the starter button once. I had to rev the engine a bit just to get the rpm's going. Could it be a problem with the starter, or is it just because there was only a half tank of gas? Thanks!

james311 · July 11, 2010, 10:02:29 AM

Did you try switching to reserve to see if maybe the tank just wasn't full enough? That happened to me when I first got it.

romulux · July 11, 2010, 10:06:25 AM

Was it already hot? If you put the choke on on an already-hot bike you can flood it and it won't start easily.

rock_rebel · July 11, 2010, 10:08:29 AM

I'll try that, thanks. Is it also normal to use an entire tank of gas without switching to reserve? This has happened a few times, or when I switched to reserve the bike did't last for very long before it died. Could it be a valve problem perhaps? I've had the GS500F for 2 years and am still a newb lol.

Elijafir · July 11, 2010, 10:15:08 AM

Sounds like your hoses are crossed and reserve is on and on is reserve. There is about 20 threads on here with tank to petcock diagrams. I think it's on the wiki too.
Also, if you ran out of gas and then added a half of a tank.. you need to switch the petcock to Prime for about 30 seconds or a minute to let the floats fill up. (Just noticed you said it's an F. Is it Fuel Injection or does it still have a carb?) Eitherway if you ran out of gas you still need to let the fuel system prime up.

rock_rebel · July 11, 2010, 12:18:54 PM

Just found the solution to my problem. All along I thought the PRI on the petcock meant "primary" which would mean primary tank. I had no idea that it was use to prime the bike

So what should the petcock be set to? Turn it all the way down? I'm not getting much juice on reserve and according to one of the threads here the petcock set to PRI would cause that problem.

Elijafir · July 11, 2010, 03:21:24 PM

The "PRI" (PRIME) setting is ON AND RESERVE and bypasses the vacuum controlled fuel shut off, so that you can fill the float bowls (prime the fuel system) in the event you have ran out of gas or the bike has been sitting for a while. The ARROW on the petcock should be pointed towards ON (Down on mine..) Horizontal for RES and up for PRIme. Even with the RESERVE setting you will still have some fuel left in the tank.. giving you the illusion that you have fuel left. (About 1/4 to 1/2 of a gallon left BELOW the reserve tube.) You said you have an F so i think the tank is a LITTLE bit bigger.. On my E.. A full tank will get me ~130 miles (2.5 gallon) and I hit RES and look for a gas station.

If you leave the petcock set to PRI for a little while (with the bike off) you run the risk of flooding your engine and the problems that come along with that.

(It's all the same tank. The "ON" tube is approximately 1 gallon "higher" than the "RES" tube. The "RES" tube is about 1/4 to 1/2 gallon "higher" than the bottom of the tank to help prevent sediment flowing into the fuel system, even though there is a "fuel sock" in the tank.)

james311 · July 14, 2010, 08:32:34 AM

Quote from: Elijafir on July 11, 2010, 03:21:24 PM
The "PRI" (PRIME) setting is ON AND RESERVE and bypasses the vacuum controlled fuel shut off, so that you can fill the float bowls (prime the fuel system) in the event you have ran out of gas or the bike has been sitting for a while. The ARROW on the petcock should be pointed towards ON (Down on mine..) Horizontal for RES and up for PRIme. Even with the RESERVE setting you will still have some fuel left in the tank.. giving you the illusion that you have fuel left. (About 1/4 to 1/2 of a gallon left BELOW the reserve tube.) You said you have an F so i think the tank is a LITTLE bit bigger.. On my E.. A full tank will get me ~130 miles (2.5 gallon) and I hit RES and look for a gas station.

If you leave the petcock set to PRI for a little while (with the bike off) you run the risk of flooding your engine and the problems that come along with that.

(It's all the same tank. The "ON" tube is approximately 1 gallon "higher" than the "RES" tube. The "RES" tube is about 1/4 to 1/2 gallon "higher" than the bottom of the tank to help prevent sediment flowing into the fuel system, even though there is a "fuel sock" in the tank.)

so lets say that my bike has been on PRI for about two weeks, and it starts really easy, just give it a bit of gas, a little bit, on start and it starts first try and idles fine.

Are the tubes wrong? You said the thing would be toast if it was on for a while?

utgunslinger13 · July 14, 2010, 09:04:16 AM

You'll just have to look at the routing of each fuel hose. The petcock under the tank will have 2 hoses coming out and you need to follow them to the frame mounted selector to ensure they are not backwards.

Leaving it on prime can cause fuel to leak into the airbox and engine and if enough fuel leaks into the engine you can cause severe damage. I believe if your float needles are adjusted correct and are not worn this will not happen as it will shut off the flow of gas.

However, with it being in PRI for 2 weeks straight you might want to pull the spark plugs and check their condition. If they are wet you might have slowly flooded it causing it to have trouble starting. If they are wet I'd suggest letting them air out for a couple days (leave them out of the engine so the gas can evaporate off the cylinders/pistons). Make sure no water can get in from rain, etc.

Once you get the fuel lines ran correctly, only run the bike with the frame mounted selector in the ON position and switch to RES (reserve) if you let the tank get that low. Only use PRI if you let the bike sit for an extended period of time and it has trouble starting at first (and then only leave it there for ~30 seconds and then switch it back to ON/RES).

Agent4573 · July 14, 2010, 09:23:06 AM

Quote from: james311 on July 14, 2010, 08:32:34 AM
so lets say that my bike has been on PRI for about two weeks, and it starts really easy, just give it a bit of gas, a little bit, on start and it starts first try and idles fine.

Are the tubes wrong? You said the thing would be toast if it was on for a while?

It won't do anything bad to the engine, however it might screw up the petcock. The floats in the carbs will stop the flow of gas at the right level to run the engine correctly. If one of the floats sticks open and you're in prime, you run the chance of having your entire fuel tank dump out of the carb. My bike didn't even come with a petcock, just a line from the tank to the carb. I cut the tube and put a 90 degree ball valve in there so I can turn the fuel off in emergencies, but 99% of the time I just let the floats do their jobs.

james311 · July 14, 2010, 11:13:29 AM

What should I do? Should I go switch it to off till I take the tank off tomorrow/drain it and put it back together the right way?

Elijafir · July 14, 2010, 02:13:05 PM

Your lines may not be crossed if you've just been running it on PRI all the time. It's not for sure that it will ruin anything to leave on PRI or a long time.. it just runs a risk. Before you do anything else.. you should fill the tank.. set the petcock to ON.. start it up.. run it.. see how it does. PRI is for filling up the floats if you run them out of gas or if the bike had been sitting for a long long time. You may be having some other kind of problem besides fuel delivery?

james311 · July 14, 2010, 06:14:41 PM

Quote from: Elijafir on July 14, 2010, 02:13:05 PM
Your lines may not be crossed if you've just been running it on PRI all the time. It's not for sure that it will ruin anything to leave on PRI or a long time.. it just runs a risk. Before you do anything else.. you should fill the tank.. set the petcock to ON.. start it up.. run it.. see how it does. PRI is for filling up the floats if you run them out of gas or if the bike had been sitting for a long long time. You may be having some other kind of problem besides fuel delivery?

Thanks for the reply, I'm not have any fuel delivery problems, throttle is responsive when I'm riding it, it starts easily,just have to nudge the gas a bit, other than that its fine.

I came back from work today and gave it a good smell, smells like gas near the carbs, not a pungent oder just "normal"

Elijafir · July 14, 2010, 06:57:16 PM

Maybe the floats are adjusted just a touch low.. do you use the choke to start? Maybe the choke linkage is loose?

james311 · July 14, 2010, 06:59:50 PM

Don't really use the choke when it gets started I hold the throttle to around 1,500-2,000 for about a minute or so.

Elijafir · July 14, 2010, 08:00:41 PM

Yeah well, if you're not using the choke you will have to give it a little throttle to keep it running at first. When I start- I put the choke half way down. Start it. It usually takes a second or two to be up in 3-4k range. I just adjust it down slowly keeping it in the 1500-2000 range until no choke is required to keep it above 1k. I ride with partial choke for a couple of miles.. I don't sit around waiting for it to warm up.

james311 · July 14, 2010, 10:15:58 PM

Quote from: Elijafir on July 14, 2010, 08:00:41 PM
Yeah well, if you're not using the choke you will have to give it a little throttle to keep it running at first. When I start- I put the choke half way down. Start it. It usually takes a second or two to be up in 3-4k range. I just adjust it down slowly keeping it in the 1500-2000 range until no choke is required to keep it above 1k. I ride with partial choke for a couple of miles.. I don't sit around waiting for it to warm up.

I kind of high jacked this guys thread if you didn't realize, I'm not in this thread because of bad starts I'm in this thread because:

Quote from: utgunslinger13 on July 14, 2010, 09:04:16 AM
You'll just have to look at the routing of each fuel hose. The petcock under the tank will have 2 hoses coming out and you need to follow them to the frame mounted selector to ensure they are not backwards.

Mine has been on PRI for a while now

Leaving it on prime can cause fuel to leak into the airbox and engine and if enough fuel leaks into the engine you can cause severe damage. I believe if your float needles are adjusted correct and are not worn this will not happen as it will shut off the flow of gas.

However, with it being in PRI for 2 weeks straight you might want to pull the spark plugs and check their condition. If they are wet you might have slowly flooded it causing it to have trouble starting. If they are wet I'd suggest letting them air out for a couple days (leave them out of the engine so the gas can evaporate off the cylinders/pistons). Make sure no water can get in from rain, etc.

Once you get the fuel lines ran correctly, only run the bike with the frame mounted selector in the ON position and switch to RES (reserve) if you let the tank get that low. Only use PRI if you let the bike sit for an extended period of time and it has trouble starting at first (and then only leave it there for ~30 seconds and then switch it back to ON/RES).

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Starting problem