87 Gs450l - Trouble Getting On the Road!

[Guest]

Hey all,

I can't get my bike going this spring! Well. When I first tried to start it, it started and ran for about a 1 minute great, very little trouble starting even though it was 30 Fahrenheit. Periodically I kept trying again over the course of an hour with nothing. Discouraged I took a break, and put the battery back on the tender. When I came back I noticed the vacuum hose wasn't 100% connected, and it needed replaced anyhow so I replaced it, positive I found my problem. Threw the battery back on with the new hose 100% attached, and the bike started great! For about a minute and it slowly dropped in idle then quit, and wouldn't start again.

To me, I don't think it is the battery because it started no problem? Although, it is time for a new battery, as it's the same one that was on the bike when I bought it two years ago, and I don't believe it was new.

This past winter, I dipped the jets in carb dip, and sprayed out all the passages in the bodies the spray. I didn't want to risk dipping the bodies in the carb dip as well, seen as how my bike was running great the previous year. I set the fuel screws to the standard two turns out, and planned on syncing them after getting it running. So, the screws are still at two turns out currently.

I also replaced the exhaust gaskets, and there was no leaks that I could detect from feel.

I drained the fuel tank by putting it on prime, and every few days shifting it to get the last drops out. after about a week I placed 2 oz of stabil into the tank and turned it off for the winter. The battery was on a tender 75% of the winter, especially the weeks leading up to this spring season. Bike was kept in an unheated garage, with exhaust ports and intake ports covered.

One other note, The first time I installed the battery and was placing it into position after being wired up, i grazed the electrical mounting plate with the positive terminal and it sparked pretty vividly, which seemed very odd. The ground wire is firmly grounded to the frame. I know near nothing about electrical!

Spark plugs were from last season, and both look in great condition with a tanish color.

Also compression was checked over the winter, and I do not remember the readings but they were great.

Fresh fuel, 91 grade. . . From a smaller gas station in a small town

I have fuel flow to the carbs at least.


My next course of action is to just take the carbs apart and take a look, If I find nothing I'll buy a new battery, any further insight? I think I provided all the neccesary information, if you have questions ask, but I might be away from the computer until Sunday evening. and the motorcycle as well.

Mark

[almarconi]

You need to check for fuel, spark and air. If you have gas in the tank, put the petcock on prime and allow gas to flow into the carburetor bowls. Do your carbs have a drain screw in the bottom of the bowl? Open it and see if gas runs out. If it has gas in the bowls that is a step in the right direction. Apply choke and crank the engine several times, remove a spark plug and see if it is wet. If it is that means you have fuel getting to the cylinder. While the plug is removed, hold the tip against the cylinder head, crank the engine and see if you have spark. If you do you are almost there. Check the air filter on the bike, make sure it is clean and that there are no critters or nests in your airbox. If you have a voltmeter, make sure your battery is at least 12.5 volts. One thing you can try is a quick shot of carb cleaner in your airbox. Apply choke, crank it a couple times and see if the engine will start. If it will, more than likely your problem is dirty/clogged carburetors.

[Gorminrider]

maybe the vacuum petcock is failing...Leave it on prime and see if it keeps running. if so, it's the petcock's vacuum function.
more: When you suck/blow on the petcock vacuum line,(find a bit of hose that fits ) you can often feel the "valve" inside moving back and forth. You can disconnect fuel line and test more by applying suction/pressure to make it flowor not ..

[Markus]

I know for a fact that when I leave it on prime the gas continuously flows from the petcock, I thought that was how it was supposed to function? Maybe I misunderstood.

just to rule out the battery I purchased a new one. I'm fairly confident this isn't the issue. I'll look into the petcock tonight when I get home if it's not too late, thanks for the replies so far.

Also I remembered another thing, i read multiple articles about using cooking oil to oil the foam filter, previous years I ran it dry because I didn't know better. I cleaned and oiled it last winter. If the battery doesn't the issue I guess I should clean that out? Maybe the cold temperature with the cooking oil made it to sludgy and restrictive?

**edit** I think you meant leave it on the on position and see if fuel is flowing. If that is the case no fuel flows when it's in the on position.

[Gorminrider]

yes, that's almost what I meant. ...
Run the bike with the fuelcock on Prime. Just leave it on Prime. Does that "fix" the dying problem? If so, you need discover why the bike won't keep running when the petcock is at "Run" or "Res"...ie: a new or repaired petcock . It's just one idea for your symptom, but so easy to test.

speaking of ideas....cooking oil in the air filter? Why? Cooking oil goes rancid. and sticky. Yuck. What's wrong with Motor oil ?

[almarconi]

Also I remembered another thing, i read multiple articles about using cooking oil to oil the foam filter, previous years I ran it dry because I didn't know better. I cleaned and oiled it last winter.

Never heard of using cooking oil. I would wash it with dish soap and warm water, shake/squeeze out the water and let dry. If you must use oil, use a small amount of motor oil. Both my bikes have K&N filters and I usually use less than 1/2 oz of oil on each of them.

[tkent02]

What's wrong with using filter oil?

[almarconi]

I went and checked the K&N website, not all of their filters require oiling. The product specification page for the particular filter lists whether they require oil and the recommended amount. In the case of the OP, I don't know what kind filter is in his bike. The stock ones that I had for the GS 750 were made of paper and didn't require any oil. I think the 850's used a foam element but I'm not sure if it needed to be oiled or not.

[Markus]

yes, that's almost what I meant. ...
Run the bike with the fuelcock on Prime. Just leave it on Prime. Does that "fix" the dying problem? If so, you need discover why the bike won't keep running when the petcock is at "Run" or "Res"...ie: a new or repaired petcock . It's just one idea for your symptom, but so easy to test.

This was the solution! So simple! Thanks for saving me tons of time, because I know this would of been on the end of my check list. I put it on prime, waited, then started and bike started up great, So I believe I understand the problem now! Unfortunately, It's time to get some rest before I do any further wrenching on the bike. Seriously! That was a great idea, I'm not sure how you even suspected that with the information I provided.


Concerning the cooking oil air filter. . .I'm not honestly sure, I guess i thought it was neat trick, and I had a bottle of cooking oil that was not in my preference to cook with, so i decided to find another use for it. haha. I didn't know motor oil worked as well? This seems more reasonable! My bike has the stock air box currently with a foam filter, the gs450L. The foam filter was cut out by the previous owner, I do not know if it was originally a paper filter or not honestly.

I'm going for a ride hopefully tonight! I'll just have to push off my college professors. . . I think they'll understand. ha!

While this post is going, in preparation for tonight, how do I go about fixing the vacuum function? I just redid the carbs and checked floats and replaced o-rings, so for a temporary fix, there shouldn't be any dilemma riding with it on prime for a night. . . correct?

[Gorminrider]

No, there should be no issue running on "Prime". It is like the older style fuel taps..= ON. .


However-(there always is an "However") if you drop your motorcycle on the ground, the gas will flow through the carbs until your tank is dry.
and Keep an eye on it anyways...sometimes old bikes' carb floats and needle fail so on "Prime", the bowls will overflow.... so it's a good idea to Turn the tap to run when you leave the bike...
First and best fix is to replace. Second is to find the problem by dissassembly and replace needed parts with a kit that is about 50% of a new tap price. This is known to be iffy. I've never bought a kit. Sometimes, I can fix, but new is better .

The vacuum-activated gas tap is an innovation to the ol' "on-onResrve-off" taps...for safety and convenience, your gas is not intended to flow unless the motor is running.

I thought original Air filters were all re-useable foam + a few drops of oil for these. if you can find the right type foam (urethane ? I believe is oil resistant?)

[almarconi]

The few times I have left my bike on prime and "forgot" about it, I ran out of gas, leaving me stranded. I have never had luck with petcock rebuild kits, it is less of a headache to just replace them.