Please Help! May have destroyed bike!

[jager1313]

Hi Everyone,

Sorry I haven't posted in a while, but now I desperately need some help.

Over the long long long winter here in Minnesota I decided to take apart and clean my carbs. I also decided to change my handlebars on my GS550L since the originals were so terrible.

I bought myself a Clymers manual and went on my way. I cleaned the carbs per the carb clean up series, everything went together just fine. I had to force the carbs in after dropping the airbox and 3 hours of hard pushing.

I took off my old bars and put on brand new ones from BikeBandit. I did not buy new lines and just sort of rerouted the long clutch and throttle lines around to still fit.

I left the tank drained and empty all winter and now I go to start it up, it turns over but nothing happens! I checked the spark plugs, they are sort of white. The carbs are filled with gas. I just don't know what to do. I will try and take the carbs apart again this weekend. Maybe taking things apart and putting them back together will fix it.

Any help is welcome! Thank you in advance! Any specific pictures I can post to help diagnose?

[madjack57754]

I doubt you really hurt much of anything. check for spark. If non, check the handlebar kill switch to make sure it's not grounding out Trace the wires back and find the plug in connector. unplug it then check for spark again.
If you have spark, Spray a bit of carb cleaner into the open airbox.
Remember that to fire you need 3 things, air, fuel, and an ignition source. to run you need them in proper proportion to each other. Try these and get back if it still doesn't work

[uudfourty]

Did you prime the carbs?

[KiwiGS]

Hows the battery?

[spyug]

Everything already said plus:

1) Pull the hose from the tank to the carbs and holding a jar under neath turn the valve to prime. Got gas flow? Put hose back on. Turn back valve to run position ( i.e vacuum control..gas won't flow til engine runs)

2) pull one plug. Reattach plug wire and rest the plug on the cylinder or head. Crank it over Got spark?

3) Fully charge battery on a trickle charger. Clean both battery terminals and make sure you have a good ground from the battery to frame or engine block. Crank it over. As Kiwi mentions, you need to have a strong battery with 12.5 or more volts. These old bikes will crank but not fire if the battery runs much below 12.5v so make sure it is good and topped up or you're wasting time and effort.

As mentioned we need to confirm gas and spark. With a fresh carb install you will likely need to prime first so turn the valve to prime and turn on the enricher (choke). You might need to crank for 20 or 30 seconds to get her to fire the first time.

Don't lose heart...it'll work.

Report back when you've got her purring:-D

Cheers,
Spyug

[skreemer]

umm folks he rerouted all his cables...

check and make sure your choke cable actuates and the throttle cable is doing it's thing.
I've routed cables incorrectly before(throttle cable) and it makes things interesting depending on the height change...

[jager1313]

So i am pretty sure the petcock is fine, I took off the gas tank yesterday and drained it all using the prime setting. The on, and reserve setting lets a small trickle of gas out. Is that normal?

I set the setting to prime before, and tried to start but nothing happens. I removed the bottom bowl screws on two carbs to see if they were filled, and they were.

I will check for spark today. But I want to make sure I dont shock myself and also there is a lot of gas everywhere, so I dont want to set anything on fire. So I should take out a sparkplug and plug in wire and let hang touching the crank case? Should I not hold the spark plug?

I think the battery should be ok, I hooked it up to my car and tried starting. It turns over super fast. When I take it off the car battery, the turning over starts fast then dies down as I keep the start button pushed.

Should I be turning throttle as I try starting? The clutch cable and choke cable are super super tight after the "rerouting". I would like to buy new lengths, but I dont know what lengths they come in. I changed to superbike bars from bikebandit. If anyone knows where I can order different lengths of cable please link me.

The airbox... when I took the carbs out I took out the filter and washed the foam inside. Then I soaked it in motoroil. Should I have just gotten a new one? Looks like it is the original from 1981.

How do I knwo if gas is getting into cylinders?

I will check for spark and report back.

[spyug]

First off you cannot and should not assume anything with bikes. Always check, test and eliminate. Be methodical. It is the only way to sort through problems like this.

You have gas. Good you can eliminate one issue. If gas is in the carb, it is getting to the cylinders unless you plugged something up in which case gas will likely be pi$$ing out all over the place. You can check this when you pull a plug, if it is wet and smells of gas you know your carbs are working.

You now have to determine spark. DO NOT PULL THE PLUG AND TEST FOR SPARK IF THERE IS ANY GAS OR GAS VAPOUR ANYWHERE NEAR THE PLUG. You know why.

Before doing the plug test clean it off with a wire brush or sandpaper and make sure it is gapped properly ( as per your manual). Better yet spend a few bucks and buy some new ones.

If safe do do so try the test as I mentioned but before you do test the battery. You need to measure voltage with a digital multimeter which you can get from most any automotive or electrical supply shop. They are now very cheap and I've seen them on for $10 or even less. You must have 12.5 volts or better (measured across the poles). Your battery needs to sustain this for at least 2 or 3 minutes or so as you my need to crank a bit at first. If it drops off dramatically in voltage within this time frame it may be suspect. As previously mentioned, the bike will crank and crank but not fire. There is just not enough juice to do both.

When cranking it over do not twist throttle, use only full enricher (choke). As it starts to run and becomes warmer dial down the choke so as to not over rev the engine. It can sometimes help if you shoot a teaspoon or so of gas into each cylinder via the plug hole. Gas only, never starter fluid ( ether) as this can blow off the head or at least seriously damage it or valves.

Try these suggestions and report back but remember test and check.....don't assume.

Cheers and fingers crossed for you.
Spyug.

[uudfourty]

( as per your manual).

Ah, yeah... if you don't have one, it would be in your best interest to get ahold of one.

[Big T]

So i am pretty sure the petcock is fine, I took off the gas tank yesterday and drained it all using the prime setting. The on, and reserve setting lets a small trickle of gas out. Is that normal?

Yes, and no. There should not be any gas coming out when set at "On". New petcock needed, but not to get it started.

So I should take out a sparkplug and plug in wire and let hang touching the crank case? Should I not hold the spark plug?

Just lay the spark plug on the head and don't touch it unless you really need a good jolt of electricity.

Should I be turning throttle as I try starting? The clutch cable and choke cable are super super tight after the "rerouting". I would like to buy new lengths, but I dont know what lengths they come in. I changed to superbike bars from bikebandit. If anyone knows where I can order different lengths of cable please link me.

I'm unclear how putting superbike bars on caused your cables to be tight. You need to put them back the way they were, they should be too long then. If needed, cables off a 450 "S" will be shorter.

The airbox... when I took the carbs out I took out the filter and washed the foam inside. Then I soaked it in motoroil. Should I have just gotten a new one? Looks like it is the original from 1981.

This is your problem. No air due to too much oil on the filter.

How do I knwo if gas is getting into cylinders?

The spark plugs will be wet and smell like gas

You have a double header going on here - too much gas and not enough air. To start with, pull out a spark plug and check for spark. Is it wet?

Then , pull out the air filter and try to start the bike. Does it start now? It will run ragged, but if it runs, then you can correct your fuel/air problems.

[BassCliff]

Not dead, just sleeping

Hi Mr. jager131,

I apologize if this is redundant.

So i am pretty sure the petcock is fine, I took off the gas tank yesterday and drained it all using the prime setting. The on, and reserve setting lets a small trickle of gas out. Is that normal?

No, this is not the desired operation. In the "ON" or "RES" position, the petcock should not allow any gas to flow unless there is vacuum applied to the vacuum line. This is probably not the cause of your starting issues, but it sounds like you might have a little leak in your petcock diaphragm.

Should I be turning throttle as I try starting?

Generally, you should not actuate the throttle until the bike has started. To do so will disturb the vacuum the carbs supply to the petcock.

The airbox... when I took the carbs out I took out the filter and washed the foam inside. Then I soaked it in motoroil. Should I have just gotten a new one? Looks like it is the original from 1981.

It sounds like you may have over-oiled your air filter. The air filter should be very lightly oiled. If you've used too much oil it will greatly reduce the air flow into the carbs. It can't hurt to pick up a new one if yours is old and rotten. I use a can of aerosol spray filter oil. A couple of quick spritzes is all you need.

Best of luck to you. Keep us informed.

Thank you for your indulgence,

BassCliff

[Roostabunny]

No, this is not the desired operation. In the "ON" or "PRI" position, the petcock should not allow any gas to flow unless there is vacuum applied to the vacuum line. This is probably not the cause of your starting issues, but it sounds like you might have a little leak in your petcock diaphragm.

Hey Cliff, it's the On and RES positions that require vacuum. PRI flows without vac. I know you know that - just avoiding confusion cause you said something different.

Since he's getting trickles in ON and RES, I think you're right about the petcock diaphragm being blown.

It's a normal failure, Jager, and the slightly prevailing opinion (Brwringer always votes twice) is to buy an OEM replacement. That's what I did - took precisely 7 minutes to replace and it works perfectly now.

Course, I doubt that's what's keeping the bike from starting, but you'll get it running, and soon it will be time to replace that valve. My favorite part - removing the tank without needing to control the dripping fuel.

[twistedwankel]

So i am pretty sure the petcock is fine, I took off the gas tank yesterday and drained it all using the prime setting. The on, and reserve setting lets a small trickle of gas out. Is that normal?
No. On run or reserve no gas should come out unless the engine is running.

I will check for spark today. But I want to make sure I dont shock myself and also there is a lot of gas everywhere, so I dont want to set anything on fire. So I should take out a sparkplug and plug in wire and let hang touching the crank case? Should I not hold the spark plug?
No. Just touch the plug to a good ground. Dark is best as spark is hard to see. Better get some air in there like you said and get the gas fumes out first.

Should I be turning throttle as I try starting? Shouldn't have to touch the throttle if using the choke full. The clutch cable and choke cable are super super tight after the "rerouting". I would like to buy new lengths, but I dont know what lengths they come in.
This is not good. Binding cables will kill you.

The airbox... when I took the carbs out I took out the filter and washed the foam inside. Then I soaked it in motoroil. Should I have just gotten a new one? Looks like it is the original from 1981.

Leave out the filter until you get it running. Make sure you don't suck a rag or dirt in there tho'. Replace that filter with a new one before you go riding.

How do I knwo if gas is getting into cylinders?
By now you probably have wetted the spark plugs. Pull one out and see if it's gas fouled. If so pull them all and dry out the cylinders.

I will check for spark and report back.

So there are 3 reasons mentioned before as to why it won't fire off. The bold is an answer to your specific questions. Good luck.

[waterman]

If this was my bike, I would jump bike from car and see if it would fire up. No throttle, just choke full out, petcock on run or reserve if tank is low. Crank for 20 seconds wait a minute crank 20 seconds again until running. After bike starts disconnect jumper cables and let scream on choke until it will not bog or wish to die when given throttle. This will eliminate bad battery.

Onto your questions. To check for spark, remove cap from plug, unscrew plug from motor. Reinsert sparkplug into cap and then place sparkplug onto cylinder head near sparkplug hole. Make sure it is touching engine. Crank motor over with starter and observe spark if present. Easiest to do at night or in a dark situation. If you must hold, use gloves and touch the sparkplug cap only. If you are touching plug you may find out if your coils are working:shock: I recommend only to do this if you like pain, high voltage is a rush...

As others have stated, a dribbling petcock is usually a failed petcock. Likewise, replace ancient air filter and very lightly oil it. Neither of these should greatly impact whether bike starts but will need attention soon after.

Cheap insurance, new sparkplugs (couple bucks each), fresh gas (arm and leg but what can you do about it), fully charged battery. Once running, report back, we can then move on to tuning questions. Good luck.

[BassCliff]

Oops!

Hey Cliff, it's the On and RES positions that require vacuum. PRI flows without vac. I know you know that - just avoiding confusion cause you said something different.

Thanks Mr. Roostabunny. Yep, I mis-typed. Good catch. Sorry if I caused any confusion.

Thank you for your indulgence,

BassCliff