GS850GL Stutter and pop.

[KDS111]

Hello all,
I have a 80 GS850GL, 25,000 miles.
All stock, no mods. I just bought it and put it on the road.
Riding along after about 7 miles on acceleration it started to stutter and spit and pop out of the exhaust. Its seems fine running around 2,000 rpm's. When giving it throttle it will spit,stutter and pop. It idles fine and revs fine. Just under a load it seems to be a problem.
All help is certainly appreciated.

[Big T]

Sounds like you need the basics

Valve Adjust
Carb clean
New O rings in carbs and intake boots

[BassCliff]

Greetings and Salutations!!

Hi Mr. KDS111,

There are a couple of maintenance lists in your "mega-welcome" that will usher you into GS-topia if you follow the prescribed procedures. Let's get started.

I'm glad you found us. 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", the Carb Rebuild Series, and the Stator Papers. 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

[coolksprt]

I second Big T's ideas. You should shim your needles also as long as you have the carbs out. Will do wonders and takes about 10min with the proper tools. Can be found by searching or on basscliffs site.

Kev

[bwringer]

I second Big T's ideas. You should shim your needles also as long as you have the carbs out. Will do wonders and takes about 10min with the proper tools. Can be found by searching or on basscliffs site.

Shimming the needles is not needed at all on a GS850 if the intake and exhaust are stock.

[KDS111]

Thanks for the help and.....

Just to add something, The bike starts fine.
It idles fine and revs up with no lag and no poping, backfiring etc.

[Steve]

Just to add something, The bike starts fine.
It idles fine and revs up with no lag and no poping, backfiring etc.

That shows that the idle circuit in the carbs is fine.

What about the rest of them?

Since you just got the bike, do you have any idea of its service history?
When was the last time the valves were adjusted? If you don't know, it's time to check them.
When is the last time the carbs were cleaned and had new o-rings installed? If you don't know, it's time to check them.
When is the last time the carbs were synchronized? If you don't know, it's time to check them.

Do you see a theme going here? If you don't KNOW, it's time to find out.

.

[coolksprt]

Shimming the needles is not needed at all on a GS850 if the intake and exhaust are stock.

you sure? I did this with my stock everything gs850 since that 5-7rpm range was giving out and since I shimmed them it's been smooth sailing...
Just talking from expereince

Kev

[chef1366]

I shim every carb set that comes my way. One washer for stock, two for aftermarket pipe and three for pods.
No complaints yet.

[KDS111]

Explain shim

Please explain the shimming of the carbs.

[chef1366]

You raise (richen) the jet needle in the slide by removing the spacer over the clip and replace it with less heigth of washers.
You have to take out the slides and remove the needle by getting on the inside of slide with a long pair of needle nosed pliers and removing a circlip.

[bwringer]

you sure? I did this with my stock everything gs850 since that 5-7rpm range was giving out and since I shimmed them it's been smooth sailing...
Just talking from expereince

Kev

Yes, I'm sure. And no one has ever accused my GS850 of running badly... Shimming the needles is not needed on a GS850 with stock intake and exhaust. It probably won't hurt anything except perhaps mileage if you insist on shimming the needles anyway.

Anyway, all this is distracting from solving the OP's original problem.

You likely have two possible problems -- the valve clearances need to be checked and adjusted, and the the airbox needs to be sealed with foam weatherstripping on the sides and where the filter mounts. Basically, make sure air only enters the airbox where it's supposed to (the array of holes in the bottom and via the snorkel) and can't leak in where it's not. Make sure the air filter foam is VERY lightly oiled and not crumbling, and make sure the air filter makes a good seal against the top of the airbox.

A third possibility is that the "snorkel" is missing from the back of the airbox.

[KDS111]

Airbox seal

The PO said the carb were cleaned last season. There are new rubber boots between the engine and carbs with allen head bolts. There is weatherstrip on the airbox covers. I notice on top of the air filter assembly there is a large bead of (silicone???) on the top of the assembly. The K&N filter looks clean. The filter assembly does not appear to be a tight fit on the top. What needs to be replaced or fixed in this case.

[bwringer]

Clean the goop off the top of the air filter and put some self-adhesive foam weatherstripping on the top of the filter so it seals to the top of the airbox. Once the weatherstripping is adhered to the filter, you can put a thin layer of grease on top of the foam so the filter can slide into place.

The K&N filters usually work fine -- you might want to get a K&N clean & re-oil kit (available at any auto parts store) and clean and re-oil it.

[BassCliff]

Hi,

Part of the joy of owning a GS850 is putting weatherstripping here:



And here around the top of the air filter cage assembly:




Also see:

Airbox Sealing
(by Mr. Roostabunny)

Thank you for your indulgence,

BassCliff