high rpm sputtering maybe missing

[Guest]

Im new to the gs world and bikes in general.. I made a pretty shady trade for a very questionable gs850g. It has almost 70000km with a 4 into 1 exhaust that has been chopped under the frame.. Very loud..

Bike idles great, starts everytime hot or cold with a bit of choke and relatively drives beautifully. I can cruise city or highway no problems...... Except when im heading into the 5000 rpm range it will sound like what i assume would be a miss or sputter on accelerating.

Where should i be looking into? Are high rpm issues normally fuel delivery issues or air issues? Vacuum problem possibility or coil? Bike has stock airbox complete and no apparent signs of manipulation that area.

[Agemax]

hi and welcome. i would suggest your problem lies with your exhaust system.
a 4 into 1 that has been cut down will require jetting modifications in the carbs, even with standard airbox fitted.
you should remove the carbs and check the jetting and while you are there give the carbs a proper good clean, involving soaking them in carb cleaner for 24 hours.
another option would be to replace the exhaust with another decent 4 into 1 that hasn't been chopped or even source a set of standard pipes.

do you have any pics of the bike for us to see?

[08rangerdan]

I really expected jetting to be the least of the problems. Is there a standard kit i can order to have all the necessary things to rebuild the carb properly.. O rings.. Etc.

[Agemax]

with an exhaust like that jetting will be the BIGGEST problem you have.
you can buy a complete o ring kit for your carbs from Robert Barr, a member on here.
also if you plan on keeping that exhaust you should think about getting a Dynojet stage 3 kit to get your jetting sorted.

you should also look at doing your valve clearances as they may not have been done for a while and can affect running.

nice bike by the way!

[08rangerdan]

Good to know i had no idea jetting would be affected so much by a non restricted exhaust. I don't mind the pipes myself but i don't want to cause problems by running it. I need to redo a valve cover gasket and at that time i intend to check the valves. From what I've read they should have between .001-.003" clearance, correct? Can i still get shims from zuki or is there a better source for my zuki needs? I currently cannot find a valve cover gasket from zuki but im hoping one turns up on an order i just placed

[Agemax]

suzuki still sell the shims, and the gasket. you could try ebay for the gasket but an OEM gasket is recommended.

depends on where you are in the world there is a shim club on this site, where you can swap shims to get the correct size you need. also there are quite a few members on here who have a stash of shims that you could buy,beg,swap for beer etc.

you may be really lucky and find after you have checked all the clearances that you may be able to swap a few shims about to obtain the correct clearances, meaning you may only need to obtain 1 or 2 shims.

[08rangerdan]

Ahh guess i won't have much luck conversing with those members here in canada ehh. Ill be sure to go over the valves before i put it back together. This bike is gonna be a bit of a project for myself.. Just havent decided which route to take with it. All will depend how well i can get it to run

[Agemax]

Ahh guess i won't have much luck conversing with those members here in canada ehh. Ill be sure to go over the valves before i put it back together. This bike is gonna be a bit of a project for myself.. Just havent decided which route to take with it. All will depend how well i can get it to run

there are a few members on here from Canada

[Toasty]

These bikes were jet lean from the factory, add in a 4-1 with no can and you'll have issues like you're running into. Definitely get new O-rings, do the valves, rejet and the bike will thank you for it

[08rangerdan]

Do you or anyone else have the part number for a set of 82 gs850 jets?