RPMs Sticking

[stevec6535]

I am asking this question because I've done everything that I can think of and still no luck. I own a 1983 Suzuki GS650G Shaft Drive. The Drive Train is totally stock. My problem is after I have been riding the motorcycle for about 10 mins or 6-8 miles the RPMs will not drop like they do when it first starts or within the first 8-10 mins. I will be going down the road at 3000 RPMs and pull in and hold the clutch as I come to a stop and the RPMs just stay at 3000 If I let out the clutch just a little and pull it right back in the RPMs will drop right down to where they should be and it will idle just fine. Like I said This only happens after I have been riding the Motorcycle for about 10 Mins. I have used 2 cans of starting fluid on two separate ocasions to try and find a vacuum leak and I cannot find any leaks around the boots or on the motor. The Air box is stock and in good condition. The Boots are not leaking. The carbs have been cleaned 2 times. The exhaust system is stock. It has a new OEM Petcock, New fuel line, New Fuel Filter and a new Air Filter. I can not fighre this one out. Has anybody out there had this problem or know what I should check now. Any help would be greatly appreciated.

[DanTheMan]

A hanging idle says you have an air leak or sticking slides. I found on my "boots that weren't leaking" that I had nearly invisible hairline cracks in one of the intake boots when I sprayed a leak sealant spray on them (temporary fix). If you have nice, pliable airbox boots, good clamps, new o-rings on the intake boots, airbox and filter well sealed and it still does that, there's still a leak somewhere.

[Ranger]

Had it.

Air is leaking somewhere even if you cant find it atleast that was my case. Double check your clamps on your carbs to see if they're clamping in the little groove on the carbs and verify you've done the highest rpm method.

You didn't mention if you had new o rings behind your intake boots. If not, replace them regardless before trying to find anything and do the above.

[BassCliff]

Greetings and Salutations!!

Hi Mr. stevec6535,

Yes, it seems likely you have an air leak in the intake system. The intake boot O-rings are the first suspect. These must be replaced, maybe even the intake boots themselves along with the boots between the airbox and carbs. Read more about it in your "mega-welcome".

Let me dump a TON if information on you and share some GS lovin'.

I just stopped by to welcome you to the forum in my own, special way.

If there's anything you'd like to know about the Suzuki GS model bikes, and most others actually, you've come to the right place. There's a lot of knowledge and experience here in the community. Come on in and let me say "HOoooowwwDY!"....

Here is your very own magical, mystical, mythical, mind-expanding "mega-welcome". Please take notice of the "Top 10 Common Issues", "Top 15 Tips For GS Happiness", the Carb Rebuild Series, and the Stator Papers. All of these tasks must be addressed in order to have a safe, reliable machine. Now let me roll out the welcome mat for you...



Please click here for your mega-welcome, chock full of tips, suggestions, links to vendors, and other information. Then feel free to visit my little BikeCliff website where I've been collecting the wisdom of this generous community. Don't forget, we like pictures! Not you, your bike!

Thanks for joining us. Keep us informed.

Thank you for your indulgence,

BassCliff

[waterman]

First want to welcome you to GSR, search out BassCliff and his website where you can download a factory service manual for you 650g as well as the rest of his archived information.

For your bike, it could be several things causing your rpms to hang. First, make sure there is slack in your throttle cable. Likewise check your "choke" cable and rod to make sure they are fully released. Thirdly, you may have your idle speed set too high, causing it to race. Try turning it down by turning CCW to see if this makes a change.

Typically speaking if these don't help then the carbs may need to be checked to make sure the float valves are working properly. I have statically checked the fuel level in each bowl to make sure the fuel isn't flooding motor. Usually you can find a bowl that is flooded causing this problem.

Finally, I have seen where an improperly installed slide diaphragm will cause rpms to rise, usually will be higher than 3K though.

It sounds like a air leak, may want to pull off intake boots and replace large orings as a precaution. Good luck you will find it.

[mlinder]

Or completely out-of-synch carbs. Which is, technically speaking, an air leak.

[1_v8_merc]

Sounds like a air leak,lol.

Because it takes 10 minutes for it to happen, and the rubber is probably expanding just enough, as it gets warmer.

The Spray-trick doesn't always work by the way.
I was constantly spraying my rear boots, and couldn't find the leak.

Then I suddenly found one of the boots simple wasn't tight enough....just a little bit of a turn, and the problem went away.
-------

But it's also possible that there's something wrong with your throttle cable or choke!

Did you check those adjustment screws/nuts on the throttle cable, to make sure they aren't moving? Check both ends, particularly the bottom side, make sure that nut is tight against the small fork on the carb-rack. Because if it's moving at all, it CAN cause throttle/RPM issues.....because I had it happen to me.(think you need a 7mm.....or something close.)

[Nessism]

Top Ten Newbie Issues... http://www.thegsresources.com/_forum...d.php?t=171846

2) Not replacing the intake boot O-rings. The classic "hanging idle" is most often traced to this simple fix.

[gs1100gl]

i had this same problem and it was actually the clutch cable riding against the back of the carbs

[DanTheMan]

i had this same problem and it was actually the clutch cable riding against the back of the carbs

Yep, that can happen on reassembly without putting the clip back on the clutch cable, except it doesn't wait until it's warmed up to so, it's right away.
Welcome to the forum, gs1100gl, introduce yourself to everybody in the GS owners thread, BassCliff will give you your very own welcome mat.
Oh yeah, we like bike picts and we like to know where you're located so we can give you help too.

[Dave8338]

Place your bets!!

[Mike]

Top Ten Newbie Issues... http://www.thegsresources.com/_forum...d.php?t=171846

2) Not replacing the intake boot O-rings. The classic "hanging idle" is most often traced to this simple fix.

I second this. My bike was idling at 5K. Put new boot o-rings and she purrs at about 1200.

[Larry D]

I second this. My bike was idling at 5K. Put new boot o-rings and she purrs at about 1200.

Nice Mike !!!

Are you about ready to go for a ride ? I guess we'll wait for it to stop raining and warm up a little......

What else do you have to do ? How are the tires and brakes on your 450 ?

[Mike]

Nice Mike !!!

Are you about ready to go for a ride ? I guess we'll wait for it to stop raining and warm up a little......

What else do you have to do ? How are the tires and brakes on your 450 ?

Tires: good
Front brakes: PO only used the back brakes, so they're good
Back brakes: See above. Getting replaced on Saturday

Only thing left is trying to decide if I can wrestle a little bit of life out of this chain, or just throw a new one on. Rather not spend the $150 on new chain/sprockets, but if it needs it, it needs it.

[chuck hahn]

83 650..would this have CV carbs,,,What about a pin hole in the diaphrams or the diaphram not seated just right under the top cover?