RPM Surge after sitting.

[kelticsol]

Got the bike back to running condition after a long hiatus. Money was tight and so were economic opportunities for my wife. Long story short: She's now a Stay at Home Mom.

Took her out for a ride. Everything was good at first. After a couple of minutes of riding I came to a stop sign and the idle fell off and the engine died. Then after an obvious turn around towards the house I was coming into the apartment complex in 1st gear (I try to be nice to the neighbors) the RPM's started surging up to around 4000. If I gave it throttle the RPM's would eventually drop after a couple seconds.

I'm thinking that this is adding up to redoing the carbs. But I don't want to relent to that as of yet. Especially if there might be an obvious answer I may be missing.

FYI: Airbox - Factory, No Lid, Sealed with Duct tape (It will hold water, Tested)

Carbs rebuilt but did not replace the little plugs. They seemed to be in ok shape.

Valve adjustment- Done

Gas tank - Rust free finally. (This is why it sat for so long.)

Fresh Gas with no additives.

New Petcock

Stator Papers- Done. Everything is operational and normal.

Thanks.

[BassCliff]

Hi,

The road to GS happiness always begins with clean carbs (with new o-rings) and a tightly sealed air intake system. We always worry about the petcock too. Keep us informed.

I apologize for my Profound Glimpse into the Obvious.


Thank you for your indulgence,

BassCliff

[tom203]

Did you get the vacuum hose back on from petcock to carb?
What "little plugs" in carbs are you refering to?
If you removed carbs to "rebuild " them, did you check carb boots for cracks ,cuz this is a likely place for airleaks when you retighten clamps? Any leaks would cause an idle surge like you described.

[kelticsol]

These plugs

The ones from the cylinder head to the carbs were good. The carbs to the airbox were 'ok'. I wouldn't say they were perfect but they didn't have any cracks in them. And I must say nearly impossible to get back on. I had to get a small child to help me with it.

I got the vacuum hose on no problem. I knew that was going to be a bugger. I put it onto the carbs before I put them back on the bike.

I'm leaning towards carb rebuild and and verifying all of the rubbers again. It sucks but really I'm not as an experienced rider to be dealing with power surges while I'm cruising the byways.

[Dave8338]

It does sound lean to me. Usual cause to a surge. My thought is that you will need to pull the carbs again and MAKE SURE that everything is open and spotlessly clean. Also, if you had rust in the tank, a GREAT place to look in the carbs is on the float needle screens. They tend to plug slightly with the rust sediment that is fine enough to make it through the petcock screen. The plugs you show do need to be inplace and fit snug. If the old ones did this, that won't be the problem. Cheap enough to replace and one less concern to think about.

[tom203]

These plugs

The ones from the cylinder head to the carbs were good. The carbs to the airbox were 'ok'. I wouldn't say they were perfect but they didn't have any cracks in them. And I must say nearly impossible to get back on. I had to get a small child to help me with it.

I got the vacuum hose on no problem. I knew that was going to be a bugger. I put it onto the carbs before I put them back on the bike.

I'm leaning towards carb rebuild and and verifying all of the rubbers again. It sucks but really I'm not as an experienced rider to be dealing with power surges while I'm cruising the byways.

Those plugs!! ok. But did you replace the o-rings on the idle/ air mixture screws ( sealed off with metal plugs thanks to EPA )?