Quits after idling nicely for 5 mins (GS450L 1982)

[KEITH KRAUSE]

Also, I hope you're using a couple of large fans if you let the bike idle for nearly an hour.

[Anonymous]

Re: Follow-up to "quits after idling nicely for 5 mins&

This new success doesn't make sense, so I'm still going to do all the electrical stuff EXCEPT, today I went out to fire it up, and it had a lot of trouble starting. Only would start if I held the throttle open, and after 20 secs it started pouring fuel from the airbox. I just cant win.

How does it run good for an hour one time, and the next time it decides to not work and instead it pukes fuel all over the place?

This is what I would like to know, as it seems to be my lot in life with my 850. Starts one time, but then doesn't start the next.

Has anyone else gone through this, did you ever get it sorted out, and if so, how?

[Anonymous]

Ok, new float valve (and seal) and seat is $40+ at bikebandit.com for OEM. That is if it is not on back order, or unavailable.

Any suggestions for a better price, or any suitable aftermarket components?

....And the tally keeps climbing $$$


Thanks.

[KEITH KRAUSE]

Ok, new float valve (and seal) and seat is $40+ at bikebandit.com for OEM. That is if it is not on back order, or unavailable.

Any suggestions for a better price, or any suitable aftermarket components?

....And the tally keeps climbing $$$


Thanks.

So you checked the valve and it appears to be worn as I described?
If so, then I recommend genuine parts. I've seen new aftermarket parts give poor results. I've also seen them work. But the cheaper aftermarket parts are simply not the quality the genuine parts are.
What about the float level/measurements? Did you do them?

[Anonymous]

breakthrough! maybe...

I finally had a chance to work on it again. Once again, the carbs came off the bike, disassembled the bowl end and cleaned and checked the valve, screen, valve seat. Then was about to recheck and set the float height when I heard a sloshing noise. Turns out that the side that was flooding out had a float that was taking on fuel.

Now the new dilema. Where the heck am I going to get a new float? Can this one be repaired? I dunked it under to look for air bubbles, but didnt see any, so I have no idea where the crack is.

Thanks for the support and tips so far.

Thom

[nabrams]

I had the same dilemma a while back. I just got a whole carb from eBay hoping that one of the floats would be good - and I got lucky - one of the two was good. The carb was really cheap (like about $20) because it looked really dirty on the outside so nobody but me bid on it. Now I have a bunch of spare carb parts besides - not a bad deal.

[KEITH KRAUSE]

No surprise it was a ruptured float. I don't know about letting it dry out and trying to seal it. I suppose it's possible, but I can't offer any help there.
Before trying E-bay or a junkyard, what about posting at the parts wanted section here? Whoever you deal with though, ask for a picture. The float must be the exact same float.

[beby99]

Floats are still available from dealer or ?

crotchrocket.com FLOAT $15.50
ronayers.com 0 0
mrcycles.com FLOAT $17.64
bikebandit.com FLOAT $22.76
powersportspro.com FLOAT $23.99
hondaeast.com FLOAT $22.76
mineolamoto.com FLOAT $22.76


bike schematic category
1973 GT750 CARBURETOR (GT750L
1974 GT750 CARBURETOR (GT750L
1975 GT750 CARBURETOR (GT750L
1976 GT750 CARBURETOR (GT750L
1977 GS400, X CARBURETOR
1977 GT750 CARBURETOR (GT750L
1978 GS400, X CARBURETOR
1979 GS425, E CARBURETOR
1979 GS425L CARBURETOR
1980 GS450 ET,ST,EX,SX,EZ CARBURETOR
1980 GS450L CARBURETOR
1981 GS450 ET,ST,EX,SX,EZ CARBURETOR
1981 GS450L CARBURETOR
1982 GS450 ET,ST,EX,SX,EZ CARBURETOR
1982 GS450L CARBURETOR

[Anonymous]

no more fuel leak

Ok, got the new float, installed it. I also checked the float height and adjusted them, but it really didn't seem right to me. The manual says for all models somewhere around 26mm, and for GS450's between about 21-23mm, measured without the gasket. I am measuring with the float tab contacting, but not depressing the valve spring pin.

I set it to measure 23mm. At this setting the floats are almost touching the roof of the float chamber, and when i press on them, they hit the roof before hardly moving the spring pin on the valve. This just doesn't seem right. Reinstalled everything and started her up. It ran, but the idle was eratic and ran high on its own, even with the throttle cable adjusted and the idle screw backed all the way off. It also didn't drop rpm's much after opening and letting off the throttle. I have not had this problem before. It used to be very responsive and idle around the proper 1400 RPM. The previous float settings were around 25~27mm and it was fine then.

Also, this model is factory pre-set with the air mixture screw. In fact, there is no screw, just a pinhole in a pressed in cylinder.

Can anyone confirm the float setting height? Why does the manual list the GS450 so much differently, almost to a point where it cant clost the valve if it wanted to?

Thanks

[displaced]

after the bike stalls what color are the spark plugs????

[Anonymous]

Displaced- the bike doesn't have a stalling problem anymore. Back when it was a problem, both had a sooty blackness to them.

OK-latest issue- erratic rpm's. I re-adjusted the floats back to 26mm and the bike is running much better. However, it has a wee bit of a little cough to it - not major backfiring, just a tiny intermittant hacking at idle. I would like to see it respond faster in terms of dropping rpm's when I let off of the throttle.

Any suggestions? I feel that this thing is almost ready for the road.

Thomas

[displaced]

always read the plugs. Maybe you can narrow the problem to one jug????

[KEITH KRAUSE]

I don't know the factory float setting for the 450, but I hope someone here will. Fuel level in the bowls must be correct or you can have your described problems. Once adjusted to factory settings, I hope your bike will run well again. Making a new topic specifically for float level adjustment may help.
I'd like to see your carbs though, because I think there is a mixture screw. Either on the side, pointing out and upward, or on top of the carb throat/engine side. All mixture screws are "factory pre-set". Correct screws setting is important, especially for the idle/lower throttle position performance.
Your description of the float travel and how easily it can touch the top of the bowl chamber does sound like you've adjusted the fuel level too high.
I'm sure many have their own opinion about float level adjustment and how to allow, or not allow, for slack in the float valve spring. How much is too much? Should we allow any at all? Even factory manuals may differ in their language/instructions.
Measuring without the bowl gasket is correct. Measuring to the correct part of the float (not always the highest part) needs to be correct too. (where did you measure yours at?) But measuring at the exact point of float tab to spring tip contact is where instructions seem to differ. My two seperate model factory manuals says to allow the float to REST on the float valve spring, which is how I've always done it. I do check the spring for correct tension first. You should be able to gently push in the spring about 1/2 way, release it, and not be able to pull any more of it out. But even this test doesn't mean the spring is good. Sometimes you can compare the spring tension to another one and feel an obvious difference. I've even felt a slight difference in brand new factory valves.
I don't know who's right about the correct way to measure, or how much spring travel, if any, to allow for. I just know I seem to be able to know when a valve is no good, and by allowing the float to rest on what I decide is a good valve, I've never had any fuel level related problems.
I think that by measuring without allowing the float to rest will actually result in the fuel level being higher than intended. I don't think the float valve can completely seal by just mere contact with the valve seat. In the inverted position, the amount of force created by the weight of the float depressing the valve spring is what's needed to completely seal fuel flow. This force is approximately the same as the force of the fuel level pushing up the float against the valve in the running position. If I'm wrong, I'm wrong, but this logic works for me.
By not allowing the float to rest on a GOOD valve, your described measurement will result in a too high fuel level.

[KEITH KRAUSE]

It took me awhile to send my previous message. I didn't know you were updating us/replying again as I completed it.
Also, your mixture screws could still have a factory cap on them. Look for a cap, not a screw head.