Carbs for 1015cc or 1075cc Upgrade

You can check out carb boring at this web site:

www.x-pipe.com/motorcycle.html

I bought two sets of 28's and a set of 26's from a friend that is moving to Greece. I took the pumper linkage off one set of 28's and replaced the bowls with the 26's.

Resident carb guru gave me the jet sizes i needed and he was spot on. Can't remember the size. I'll check.

I was told the 28's can be made to flow more gas than a set of 29's.Don't know enough to comment.

Any way with the 1075 and Andrews 3X the old bike screams.

I installed a set of 34's night before last and didn't have a chance to ride as the rain has started again. I do know the idle has improved to the point i can back the idle down to practacly nothing.

I'll let you know how it works.

I need to know what tools were used to clean those head ports up with. They look great.

Ok so the price of 29s is $600.00 or so. It doesnt look like they are going down any. Just keep your stock carbs if you ever decide to sell your bike. Then sell the 29s seperate. Chances are you will make money down the road as they willl prove to be a good investment. Supply and demand is going the right direction. So stop talking about it and buy a set...Russ

saxjonz wrote:

OK, I have noticed no one even mentioned the 28's that came stock on the 80 ltd. If you are looking for a bargain basement deal and maybe later put some 29's what about the 28's they have to be better than the 26's and although not 29 smooth bores they could be had for as cheap as the a stock set of 26's. Wouldn't that give you a little jump? As I have said I only read about the hp from the manual and I never rode my bike with the 28's on but I would think that they have to be a bit better than the 26's.
Anyone?

I always wondered about 28's and finally put some on a 1015cc motor. Easily noticeable diff in top end pull. I don't think it's enough though. I think bs34's are good for some real hp and these bikes jumped up in hp because they were used in place of the 26's and 28's. In other words "good carburetors". Sometimes when carb differences are noticed from one set to another it's just the fact that one set supply's more fuel to the engine. Id bet my engine would jump up 10hp if I put on 34's of the bs kind. I would like to know the diff in hp between the 29's and 34's. Don't matter how smooth they there only 29mm any way you look at it. The controlled opening of the bs's slides means high velocity all the time. To me that means faster acceleration. How'd the world get flat again anyway? We need a dyno test result of the 29's and the 34's to back me up here.

i have a set of bs34 due weds......cant wait to get em on and see the diff.......

I've been racing a '75 Z1 for 4 years now with a 1015cc kit(rings were tired-Wisco pistons,etc.)It has pod air filters(no foam,the track is pretty clean)a 4 into 1 pipe and the 28mm carbs it came with.I took it to a shop and had them jet it for me on the dyno-$320.The dyno sheet says it makes 85hp.It'll start first kick,idles,pulls strong from 3500rpm-9000rpm.I've got over 40 races on it,and all I do is general maintenance on it and repair crash damage.Unless you're at the drag strip or on a long straightaway I don't think you'll notice the difference.Jerry

34mm bs carbs, 104l.c. 93hp min. over 85hp?

I removed my 34's this morning and went through the 28's checking the float height and doubled up on the float gaskets.

I have size 20 small jet and 120 on the big jet. pod filters, open header, and 3X cams. I have the coil upgrade. The bike pulls real good up to 9000.

Accelerator pump has been disconected and i have 26 carb bowls. Roy



correction,the bike pulls good through 9500 as of today.

Roy those jets you are running are no way big enough for that bike if it's a 1015 or bigger. Mine was gutless with 120 mains. When I drilled them out with a drill bit a whole knew world of power came into the motor, like two engines intead of one. I mic'd the drill bit at 155. The engine doesn't need any choke accept to start it and that's it. This engine has a points ignition and plugs were meduim tan with the 120's. Now there more of a dark color but there still is some dark tan on them. Either way could care less what the color. I took the bike down a highway in the country when it was forty deg once. I got it up to 85 in third gear and whacked it. Man o man did that thing pull. I went throught to fifth gear redlining it all in third fourth and fifth. I have no tack so when it sounds like it's wound tight and keep going till I feel it's enough. It never really runs out of power (seemingly). Guess what color the plugs were when I took them out after that run when I got home? And no plug chop crap either. They were pure clean gleaming white. So give me 30 or 40 degrees and a dyna ignition and I'll take on the world of 600cc bikes. Ok i'll admit i'd like to hire someone who weighs about 160. I don't think or guess It would smoke them. There's enough facts in place already. I raced a zx6 and zx10 2004 models with break in miles. They were ahead a ways and my bike popped out of sec gear. Eventually I came up on the 10 and at 80mph we hit. He ended up about 100yds or better ahead but after that we locked out through fifth gear then let off. Town coming up. when we pulled up to the dairy queen the guy said he had it pegged, and the 600 guy who I never seen said "I wanna race you again" Never did had no gas to get home, spent all my money on that drill bit. I had stock cams then and a 1015cc kit. I was also impressed. I don't mean to be bragging about my bike and this is a long post but what I'm saying is these things can be real fast and more gas seems to make the needed hp to run with lighter bikes. With a 120 jet it would run like it was missing a piston. With a 112 it was snappy as lightening, came back down instantly and had tons of torque to 9000 and was fun. But it was missing one thing. You know what it is when u hit the on ramp to the freeway. BALLS. I forgot to mention I ran this fast on that cold day and the other times with no charging and a batt that for two years never seen more than 10 volts as it had a dead cell. I drlled that jet out more once and it was too much gas at 6000 or so. Someone once told me "A jet isn't just a hole you know". I really would look that person hard in the eye, maybe shake my head a little now. Waht are people REALLY saying these days? I just don't understand them as they see it. And you know. I'm glad I don't.

I have mostly been taking it easy with the bike. I just let it roll yesterday leaving work and i just happen to look down to see the 9500.

I will not be running these carbs after i get my jets from Z1E. Those 34's just do the job for me.

I know about beating on crotch rockets. They seem very suprised.

I am selling on eBay to get me a smaller chain. The bike is geared too low and i am mostly riding 55-60. Roy

So it's decided then. I'm going to pay someone for dyno time and let them tell me what I need for my engine, since there isn't a consensus.

I've been fooling with bikes for 45 years-backyard mechanic.I've done the plug reading thing with a previous Kawasaki and other bikes-really time consuming changing jets.I was lucky 'cause the shop owner trusted me and gave me a box of jets and said bring back what you don't use and charged me a few bucks.It still took me all weekend.When I took the Z1 to have it dynoed they took it from 69 to 85hp with proper jetting.The guy was right when he said I'd have a hard time finding 16hp for $320.I think you'll get what you pay for.Good luck and have fun with it.Jerry