gas on spark plug

[ninjadave7]

Hey all,
thanks for a great resource.

I just bought a 1980 GS850 GT and I'm trying to tune it up. It seems to run fairly well, with occasional high idle and sluggishness until around 5k rpm. This isn't constant, but does happen.

I went to replace the air filter boots today (the previous owner had melted them a bit...) and found gas in the airbox on the left side. I pulled the plugs and found gas on the far left plug (#1 unless i'm mistaken). I cranked the engine quickly and gas shot out of the open socket. I did the research that I could here and consensus seems to be that this is bad but I don't really know why this is happening. I'm assuming a stuck float? Also, when the petcock is set to "ON" and I pull the fuel line it just keeps running, so removing the tank is difficult. Shouldn't it be shutting off?

Any help would be appreciated, thank you!

[niclpnut]

Sounds like you need to replace the petcock.

Also, a good carb cleaning is in order.


Nic

[BassCliff]

Greetings and Salutations!!

Hi Mr. ninjadave7,

Yes, there are several tasks that you should consider. Actually, if you do all of the suggested maintenance up front, and do it correctly, you will have a much more reliable and safe motorcycle. Once all of the usual maintenance tasks are done you will have a solid baseline for troubleshooting any future issues. You'll find lots of GS850G goodness on my little website.

Anyway, 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 Cleanup 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

[ninjadave7]

Thanks BassCliff. I actually just read through some of your site, and the carb cleanup series. That's next step for sure. I'm also ordering a petcock from Z1, is it the "Petcock - Single Outlet 5/16 - 22mm bung - Left Side" that I want?

Pretty much I'm trying to eliminate the obvious first, like air cleaner boots don't seal, K&N filter doesn't sit tight against top of the box, that stuff. Then start the routine maintenance and tune up when it will (supposedly) work right.

question, once I've cleaned the carbs out, will I need to take them to get synced and tuned, or is bench-syncing enough?

thanks!

[BassCliff]

Hi,

Your petcock is bolted on, not "bung" style. Use the 44mm bolt spacing. Calling Z1 to be sure you are getting their correct part is often the best course of action. However, THIS PETCOCK has the fuel and vacuum ports on the opposite side as compared to the OEM part. Personally, I'd order a new OEM petcock from Suzuki (and O-ring) and be done with it for the next 20 years or so. It seems I've seen Jeff (who works at Z1) post recently that they can sell OEM petcocks at Z1. They're a top notch vendor.

Yes, you'll need to tighten up the air intake system. See the Airbox Sealing guide and the Air Intake Repair guide on my little website.

"Bench syncing" the carbs should get the engine running well enough to vacuum sync the carbs. You will need a couple of special tools to vacuum sync your carbs. The tools are not cheap but they are only half the price of taking your bike to a shop to have it done. WARNING! Taking your bike to most shops will be detrimental to the health of your motorcycle.

See the Carb Sync guides HERE and HERE.


Thank you for your indulgence,

BassCliff