choke probs

[mouse]

Hi peeps I'm hoping somebody on here will be able to help me out
had my carbs rebuilt and ultrasonically cleaned last year
Ive also fitted a Boyer electronic ignition
the bike is a 1979 Suzuki gs850
The carbs are mikuni slide
the exhaust is a four into one fitted with a y section that leads into two Harley screaming eagle pipes with baffles fitted.
the air box is the original type with original oil soaked sponge filter.
Right, to the problem I'm having- when the engines warmed up its great pulls great and tickover is fine
but to get it warmed up is a nighmare
the engine revs its nuts off when i have the choke pulled out and theres now way i can ride it until its warmed up
if i try to ride it before warm up it stalls straight away
any ideas
thanks mick

[Dave8338]

How long does it have to warm up before you ride?
Have you upped the pilot jets to accommodate for the pipes?
Adjusted the valves (often leads to slow warm up times if they're too tight)
Changed the intake o-rings between the head and the rubber carb runners?
If the choke circuit is working correctly, you shouldn't be able to ride it with the choke out...too much fuel.

Welcome to the GSR, you'll get a mega welcome from the mega man AKA Cliff, shortly.

[gs road racer]

It's LEAN need to find out why? Vacum line to petcock, intake o-rings, cracked intake manifold rubber. Has it always been like this? Changes made recently? Valve shims adjusted lately?

[mouse]

How long does it have to warm up before you ride?
Have you upped the pilot jets to accommodate for the pipes?
Adjusted the valves (often leads to slow warm up times if they're too tight)
Changed the intake o-rings between the head and the rubber carb runners?
If the choke circuit is working correctly, you shouldn't be able to ride it with the choke out...too much fuel.

Welcome to the GSR, you'll get a mega welcome from the mega man AKA Cliff, shortly.

hi thanks for the welcome
i haven't upped any jets m8
Ive adjusted the valves to try and cure the problem but it made no difference it takes ages to warm up before i can even touch the throttle
i will change the o rings do you know where i can get them from please
thanks once again mick

[mouse]

It's LEAN need to find out why? Vacum line to petcock, intake o-rings, cracked intake manifold rubber. Has it always been like this? Changes made recently? Valve shims adjusted lately?

its always been like this m8 since i bought it
not got a standard tank on it so theres no vacum line to the petcok
all intake rubbers look good i cant see any cracking
i will change the o rings as soon as i can get some
thanks for your help mick

[BassCliff]

Greetings and Salutations!!

Hi Mr. mouse,

Anytime the intake or exhaust has been modified there is a good chance that the carbs will have to be re-jetted. The easy way is to install a Dynojet stage 1 or stage 3 (depending on the mods), or buy a few different size jets and needles and go the trial and error route. Either way, plug chops are necessary to confirm the proper jets sizes are installed. There's more info on my website, where you'll also find lots of GS850G lovin'. (Note: with only the exhaust modified, perhaps a stage 1 kit is all that's necessary.) There are also a couple of maintenance lists in your "mega-welcome" that will usher you into GS nirvana, if you take no shortcuts.

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

[mouse]

Hi Mr. mouse,

Anytime the intake or exhaust has been modified there is a good chance that the carbs will have to be re-jetted. The easy way is to install a Dynojet stage 1 or stage 3 (depending on the mods), or buy a few different size jets and needles and go the trial and error route. Either way, plug chops are necessary to confirm the proper jets sizes are installed. There's more info on my website, where you'll also find lots of GS850G lovin'. (Note: with only the exhaust modified, perhaps a stage 1 kit is all that's necessary.) There are also a couple of maintenance lists in your "mega-welcome" that will usher you into GS nirvana, if you take no shortcuts.

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

thank you for that big ole welcome there buddy
i will look into a dynojet and let you know what i come up with
thanks once again this has been a most helpful site
cheers mick

[mouse]

dyno

had a look round dynojet uk http://www.dynojet.co.uk/jetkits/pri...ts-on-road.php and it dont look like i can get a dynojet kit for my bike
they list from 1980 onwards
i cant find anything for my year of 1979

[chef1366]

If these are VM carbs I'd raise the jet needle a notch and take out the air and fuel screws out a 1/4 -1/2 turn each.

[hampshirehog]

I wouldn't play about with the jetting if it's running the original airbox. Wrong jet size isn't what is causing your problems if it's running fine off choke.

You mentioned that the standard fuel tap isn't fitted - is the vacuum hose blocked off at the carbs? That will make one cylinder waaay lean - the other 3 will be choked so that it starts but the very lean one will make it rev - especially with all that extra petrol coming through the choke mechanism.

[mouse]

I wouldn't play about with the jetting if it's running the original airbox. Wrong jet size isn't what is causing your problems if it's running fine off choke.

You mentioned that the standard fuel tap isn't fitted - is the vacuum hose blocked off at the carbs? That will make one cylinder waaay lean - the other 3 will be choked so that it starts but the very lean one will make it rev - especially with all that extra petrol coming through the choke mechanism.

hey up m8 yes it is blocked off is there another way round it ? that you know of