1980 gs1000E,,,, cv carbys ,,rejetting????

[Guest]

hi guys,,, i,ve got all my parts to rejet my stock cv1000e carbys ,,1980,,, i,ve even got those small stainless steel washers ..that you fit on top of the needle when you raise it instead of putting back the plastic white washer ... i was told it helps with roll on .. i,ll be running oval pods .. is it worth doing the change with those small st/st washers regards oldgrumpy

[7981GS]

Still going to run the stock exhaust?

Daniel

[koolaid_kid]

Yes, the washers will help with the built-in lean spot that is CARB (California Air Resources Board) related. It helped on my virtually stock GS.
However, the recommended change when running pods, and especially pods and a pipe, is a DynoJet jet kit. Still, you can get it running adequately by installing larger main jets and doing plug chops.

[oldgrumpy]

rejetting cv carbys on 1980 gs1000e....

hi guys thanks for your info i,m running a 4into 1 exhaust,,, with an australian made megacycle muffler ...,,, i was going to run oversize jets and raise the needle .... sorry ,,i currently run a standard airbox ...regards oldgrumpy

[TheCafeKid]

Grumpy, keep in mind most of the advice youll get from this side of the world will be based on our version of the CV carbs. They're likely to be similar to yours but different enough. First of all, most countries outside of the states usually got larger pilot jets, and in some cases started with larger mains. Unfortunately over here we were dealing with a couple of different issues that started the ball rolling on increasingly heavy handed emissions and other such EPA regulations (The great gas crisis, the impending tariffs on imported motorcycles etc)

As such, and to this day, almost every single foreign motorcycle that hits these shores came lean from the factory. Even today's injected bikes in many instances are mapped toward the leaner side of acceptable. Our GSs got barely enough fuel to run without destroying the engines and this somewhat compromised their performance. As I said we generally got smaller mains and pilots, our mixture adjustment screws were "plugged" so that we couldn't fiddle with them, and our needles were not adjustable, meaning they had one clip position.

I'm not sure about Oz, but I know most canadian spec bikes had the larger jets and adjustable needles.
Of course being the "hot-rod" society that we were/are, many quickly figured out how to remove those plugs to get to our mixture screws, and through lots of research and development companies began selling jet kits that included larger jets and needles designed to work with aftermarket performance pipes and intake systems such as pod filters.
So when someone over her asks how to jet their bike for pods and a pipe the general reply is "Buy a DynoJet kit". The stock needles we got here were too fat and tapered to slowly to compensate for the added air.

With your carbs, you may find that you can in fact get the stock needles to work, and simply have to increase the size of your main jets, provided your needles are adjustable, and don't have that fat slow taper. I have a set of Canadian spec Mikuni needles and they look very little like the stock stuff we got here.

If you can, perhaps you could remove one of your needles and take a picture for us? Of course you could always purchase a DynoJet kit and eliminate 90% of the trial and error.

[1980GS1000E]

The carb slides that the needles fit into are fit with circlips and a plastic holder. Sadly the needles are not adjustable, however you can raise the needles and omit the circlip upon reassembly as the spring pressure alone is enough to keep the needles in position. Running a stock airbox and exhaust, I had to raise the needles 2 mm to get rid of the lean spot.

[TheCafeKid]

The carb slides that the needles fit into are fit with circlips and a plastic holder. Sadly the needles are not adjustable, however you can raise the needles and omit the circlip upon reassembly as the spring pressure alone is enough to keep the needles in position. Running a stock airbox and exhaust, I had to raise the needles 2 mm to get rid of the lean spot.

His may be adjustable. He's in Australia...

[oldgrumpy]

rejetting 1980 gs1000e cv carbys in oz....

hi guys thanks for your advice ,,, about 12 months ago i did pull my cv carbys apart and cleaned them all ,,, they were a pig styre... ,,in oz the had adjustable needles ...and i think from memory my jets were 108 and 40.... ,but i do remember ringing mick hone in box hill and their wiz kid,,stated they usually took the jets up 1 on main/ pilot and raised the needle up 1 notch ..and they usually worked .. i,ll have too find my jar of new jets i purchased from Z1 in the states ,,but i also got a small packet of st./st washers from a member in the states ...as i couldn,t get them here at all ... i also run a 4into 1 ,,, ,,it has a 60mm. outlet on the header ,, and when i ordered my muffler a few years ago ... the owner of megacycle mufflers in keysbough near melbourne ...said that should be a 60mm muffler ,,,we are currently making that size now ,so he made mineand sent it to me that week ... again thankyou guys ... regards oldgumpy ,,,PS... i just found my new Z1 jet i purchased in usa,,, they are main 117.5 pilots 45... .. at the time of buying i couldn,t get them in aust.. and they were 3-4 times the cost ....

[1980GS1000E]

His may be adjustable. He's in Australia...

Missed that.