GS425 carb issues?

[Guest]

So I have finally been riding after 2 years of working on my bike and now I'm fixing issues that I didn't know it needed until they failed after finally running for a bit (clutch pushrod seal, shifter seal, etc.). The other day I was riding and it started to ride rough, kind of struggling to keep it running. I arrived where I was going and then it refused to start again.

I have since fully dipped the carbs again, blew out all the passages with the compressor, replaced the float bowl gaskets, checked all o-rings, gaskets and clamps, and did a really good bench sync. I can now get it started and running on choke only. The RPM's are steady at about 1800 for about 30 seconds and then it revs to about 5000. As soon as I take off choke, it dies immediately. I can keep it running if I twist the throttle as I turn off choke but then it pops and sputters like crazy.

I checked the seal on the airbox (good), all the o-rings were changed the first time including intake o-rings, and when I have it running off choke I have sprayed all suspects for air leaks with starter spray and no change is noticed. Please help, I don't know why my bike hates me.

[pete]

Hey Brion, what's your fuel tap like? Any rust in the tank? Wondering if you're not getting fuel to the carbs...

Also, is your float level set right?

And do you have an inline fuel filter in addition to the fuel tap?

Have you checked to see if there is fuel in the float bowls?

[ikantbreave]

Thanks Pete,

I pulled the petcock and found it dirty but not terribly. I have it in the Berryman's now and will blow it all out. I did clean the tank originally with about a gallon of Evaporust and a couple handfuls of roofing nails, then swished it with Seafoam. Probably didnt get gas in it soon enough to avoid flash rust. I don't have an inline filter, the bowls are full and the float heights are set properly. We'll see how the petcock cleaning helps. Would it even run on choke if the petcock was the issue? Thanks a ton.

[ikantbreave]

So the petcock is totally cleaned and reinstalled. I am having the exact same issue. The float bowl gaskets I have are Yamaha, but I know there was a model that uses the same carbs. I did notice that there are a couple of very small holes in the center area that arent quite right. Is this my only issue or could there be a vacuum leak I'm not catching?

[pete]

Ok, what about the state of your intake boots themselves? I thought mine were good as I could squish them a bit and they still seemed rubbery.

However, they had actually shrunk, so getting the carbs in required a touch of rubber grease as the inside diameter was too small and the clamps didn't really clamp down on them firmly as the outside diameter was too small.

Got a pair from Boulevard Suzuki for about $50 and it was night and day difference. Carbs straight in, clamps do their work, no intake leaks.

[Super]

Just a small chance suggestion, here. Double check your carb bowl gaskets. I once got ready to re-install the carb bowls and glanced at the old gaskets. Realized that the new gaskets had a pressed impression that needed to be popped out of the gasket before installing them. If I didn't do that, they would have blocked an opening in the carbs. Just my .02 cents worth. Good luck.