TOPIC:

Hi, I just installed a set of pods and a jardine 4 into 1 exhaust. I'm rebuilding my carbs and was wondering if I should change my jet sizes? what would be a good sart?

I'm at sea level. anything else I should change while I'm in there?

thanks,
Mike

Hi Mike,
member rtg recommended the following to me and it works pretty well.

Stone Cold: I have an"83 KZ 1100 set up very similar to yours with 4 into I,pods etc. I have found that mine works very well with 125 main jets,stock pilots and one washer under the single position needle clip.
found washers at LOWES infastener section ..
Hillman #4 flat stainless washers , part number H#882044

The bike runs fantastic when it warms up but is a bit "cold natured". It starts fine with the enrichener all the way out but after a few seconds revs really high (4000 or so). If you move the enrichener in to the detent (half way in) it tends to want to pop a bit through the carbs. If you just pull away it runs fine and warms up in a couple of minutes. It seems to run lean at idle but only when cold. I may need a bigger pilot jet.

Good luck,
Tony T

Suggest #140 main jets and pilots #40. Leave the jet needles un-shimmed.

wiredgeorge wrote:

Suggest #140 main jets and pilots #40. Leave the jet needles un-shimmed.

Hi George, I'm trying to learn how one item relates to another on these carbs so please correct me if I'm wrong.

By taking the main jet up to #140 and dropping the needle I put more fuel in as soon as the needle lifts. The pilots going up to #40 will put more fuel in at idle. So.... we're richer at idle and I'm not getting that little pop every now and then when the engine is cold. Then when I crack the throttle open a little bit the needles lift and since I have a bigger jet I get more fuel giving me a smoother transition from idle to part throttle. Am I on the right track or am I missing something??

The #140 mains don't look like any problem to find but where do I find the #40 pilots??

BTW! Thanks a bunch for your help, I value your opinion and expertise.

Tony T

Dear Stinkfist : (interedsting name!! I bet that's a good story) anyway, something to remember re; jetting ,tuning etc. is your spark plug readings tell the story! Correctly reading spark plugs will give you an idea of engine condition hence combustion efficiency and mechanical efficiency.. the 125 mains and the slight shim under the slide needle works for me very well ..my pluugs read very well , very even and right color...I'm fortunate to have good compression and reasonably tight combustion chambers so this setup has just been fine all the way around ... if you're not too familiar with plug reading ...read up on it as it tells a pretty acurate story
rtg
'83 KZ 1100
pods, Jardine , K&N's etc.

Sorry guys, I didn't mean to hijack this thread

rtg, your advice was good. My bike runs great when warm and the plugs look good but they appear a tiny bit lean. The NGK chart said they were fine so I just left it alone. The previous owner said the bike was cold natured and that was before the pods so I just assumed it was normal, although annoying.

But again, sorry for side-tracking the thread.

stone_cold. You didn't high jack the thread. Don't worry about it. It appears that we are looking for the same info. So no worry.

Dear Stinkfist : (interedsting name!! I bet that's a good story)

Actually It's not that interesting. It's just a song title by one of my favorite bands, "TOOL".



Thanks for the info guys. This is helping me out. I'd also like to know where to get the pilot jets.

Also if there is any good tech articles on how these carbs operate I'd love to read it. I'm familiar with Holley's and i've worked on a few other car carbs but never worked on Mikuni bike carbs.

Thanks,
MIke

Post edited by: stinkfist, at: 2007/04/03 20:37

The jetting advice given was based on rejet of about 100 sets of those things a year using pods/4 into 1 or 4 into 2 aftermarket pipes and an EGA. The pilot jets can be had via www.z1enterprises.com - they are BS30/96 Mikuni pilot jets. The stock pilot jets don't have holes in them. I don't use those; I use the BS30/96 type. The stockers are the same in all other respects.

Hey George,
I searched Z1 and can't find the pilot air jets. I searched in the "advance search" area for BS30/96 then BS30 then BS then Mikuni then pilot then #40....... all they have listed under BS is an air jet for a BS30/97 and they have nothing listed under #40 I'm stumped any suggestion???

I don't want to break any forum rules or anything but can't we buy the jets from you?

O.k. I found the pilot jets for the BS30/96 over on www.motorcyclecarbs.com those bad boys must be made of gold at 6.95 each OMG!!! Any body know of a source with better pricing.

I have been scolded so many times for mentioning my business I hestitate to mention I am not a parts seller. BUT what the heck, we don't sell parts at this time.

Z1Enterprsises.com carries the needed jets. Contact them. They don't have every small part listed on their site. I personally buy parts from Z1Enterprises.com because they support the sport and offer a lot of advice and tech support to vintage bike owners. There are probably folks out there who also sell some of the same stuff but don't seem to be bike enthusiasts and you never see them taking part in bike forums, for example and if you call them and ask a question, you soon realize they are only there to sell you something.

Stone_Cold, if I had not answered and told you what the jet type was and you had called those folks and asked them which pilot jet fit your bike, do you think THEY would have told you? Hmmmm I gave you a source for those jets and I suspect the price will be a tad better.

George,
I don't want to get you scolded we'll just leave it at that.

As far as the source, I really appreciate your candor. I have done business with Z1 and they have always been great guys to work with. I'll contact them.

Thank you so much,
Tony T