1986 GS450L idle/fuel delivery questions

[C10sutton]

Hey everybody I'm new to the forums and I'm pleased I found them! So let's get started I have recently acquired an 86 gs450 that has been sitting for years. After purchasing a brand new petcock( the old one was non functioning) and sorting through the rest of my bike I cranked it over but sadly it won't stay idling. I have looked through my manual and it doesn't show me the same carbs that are on the bike which makes air/ fuel mixture a difficult task. Also the only thing I did to the carb before start up was clear out the pilot and main jet. With this being said riding it isn't necessarily what I expected it really bogged down until I left it on reserve and it miraculously had some balls. Now down to my main questions. One being even though my petcock is labeled as prime, run and res do all of them really work or is it being placed on run almost starving it for fuel? I read on another thread that these bikes don't have real reserves just a prime and run option. This brings me to question number two. My left carb leaks out of the air inlet profusely during running would this indicate a sticky float needle? Question number three has anyone else had trouble with finding the air/ fuel mixture screws? Thank you all for baring with me I look forward to your advice!

[MOC]

You need to totally tear down and rebuild those carbs with new rubber. Get everything clean and adjusted to proper spec, THEN troubleshoot. Trust me. I didn't want to believe it at first but these bikes are fiddly and a bit more sensitive to that sort of thing.

[cowboyup3371]

Run is your normal everyday setting, reserve is the last half a gallon of useable fuel left (won't actually empty the tank), and prime is necessary only when the bowls are completely dry

[BassCliff]

Greetings and Salutations!!

Hi Mr. C10sutton,

It is my custom to greet new members with the "mega-welcome". In the links provided you will find a couple of maintenance lists. Every item on the lists must be properly addressed. Skipping steps or taking shortcuts will lead to frustration at best, damage and mayhem at worse. You'll find lots of documentation, tips and tricks, pictures, "how to" guides, etc. Please read completely and carefully.

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[C10sutton]

Thanks for all of your responses so far guys!

[pete]

Hey mate, welcome! The 450's are great bikes and I like the fact that only two carbs makes it a little easier to work on too

Can you shoot up some pic's of the carbs so we can try to identify them for you? They may be aftermarket or simply from a different model/year 450 as most are interchangeable.

If it only runs on RES or PRI, there's a good chance your vacuum hose is not hooked up to the fuel tap/petcock correctly which means it won't flow fuel in the RUN position.

Leaking fuel would typically indicate a stuck float valve not shutting off the fuel supply. It can also mean a faulty fuel tap/petcock but replacing that should rule that out...

Oh, the fuel tap should really have a RES function... mine only has ON and RES, and the prime function is via a little brass screw instead of a tap position, but mine's an older '82 model.

[C10sutton]

I'm going to upload carb pics to my albums guys

[pete]

Cool, let us know when they're there and see what we can see.

[C10sutton]

Well I am having loads of trouble uploading pictures guys but i may have found a full rebuild kit from parts n more. Not sure if this would assist in carb identification but i have plugs over my pilot jets. Would those be indicative of my idle issue or do they serve a special purpose?

[pete]

Ummm... this is not going to help... it depends on the carbs

[BassCliff]

Hi,

Well I am having loads of trouble uploading pictures guys but i may have found a full rebuild kit from parts n more. Not sure if this would assist in carb identification but i have plugs over my pilot jets. Would those be indicative of my idle issue or do they serve a special purpose?

Posting Pictures To GSR (PDF file)

Those rubber plugs belong in your carbs. Your carbs must be properly cleaned. It sounds like the pilot circuit is plugged. Are you trying to run the bike without the airbox? Look on my little website for the proper carb cleaning instructions.


Thank you for your indulgence,

BassCliff

[barnbiketom]

do NOT get a "KIT"

Well I am having loads of trouble uploading pictures guys but i may have found a full rebuild kit from parts n more. Not sure if this would assist in carb identification but i have plugs over my pilot jets. Would those be indicative of my idle issue or do they serve a special purpose?

do NOT GET A "KIT"

you only need to remove the carbs, completely remove every part that can be removed, dip in berrymans, rinse and confirm the passages are clear.

then replace o-rings. the "KITS" have nonstandard, substandard parts in them and you will end up with more problems than you already have.

the parts inside can ALL be cleaned and only in rare instances need to be replaced.

in addition, you need to remove the intake boots, making sure they are in good shape and replace those o-rings between them and the head too. get your o-ring kits from Cycle orings.com

[C10sutton]

Sorry I took so long replying guys my truck gave me a headache. With that being the daily I had to fix it. I figured out my problem finally! It was me plugging the puke tube breathers. I made the assumption that that was some kind of balancer between the carbs. Anyhow it's running now but I need to rejet.