Buying Jets in outside the USA

[giraffe]

I went to the dealer and they can't help me at all finding 150 jets for the GS500, it's tough in other countries, you see all the cool mods being done to the GS and don't know where to begin buying the jets, filters etc ..

eg. there are no Parts Unlimited catalogues, or JC Whitneys or Lockhard Phillips etc or whatever !!

Does anyone here know where to get the jets in Australia ?

What are some common ways of making overseas payments ?

[JasonB]

Just tell them you want some Mikuni large round 150 main jets, that will proble get you a better response than 150 mains for a GS500. Need 2 of them.

[The Buddha]

Well then drill yours...1/16th..
cool.
Srinath

[giraffe]

"Mikuni large round 150 main jets" .. so there's only one kind of round 150 main jets by Mikuni ?

[JasonB]

nope there are small round jets and then there are hex mains, prob more than just that also.

[giraffe]

I found this supplier in northern Australia ..

http://www.mikunioz.com/main_jets.htm

As far as I know, at higher throttle openings, adjustments are made to the needle and to the main jet.

The main jet (cylinder with hole, that draws fuel from the float bowls) is 'blocked' by the needle at mid throttle openings and completely exposed (the needle does nothing) at full throttle openings.

So for a 1989 GS500 with a stock air-filter, a carbon slip-on what jets should I buy for improved performance ?

[JasonB]

Shouldnt need to change jets with your setup, did you get 122.5 mains or 125 mains and 40 pilots with your bike? If its the latter leave it and maybe adjust the mixture screws.

[giraffe]

Thanks Jason,

The current set-up seems to be working fine with the stock jets, stock airbox and the loud carbon exhaust slipon. The spark plugs seem to be the right color (white-tan insulator color)

However, I like many of us here are looking for better performance, it seems that the common trend to change the jets around when adding a pipe and a less restrictive air-filter.

This will lean the mixture so i'm looking at getting a less-restrictive filter now and the right jets,

http://www.mikunioz.com/main_jets.htm

On this Aussie website there are a few Mikuni jets, which are the ones that you guys are installing ?

It seems that with a new filter and the current slip-on, 140s will be the way to go. How do you suppose 125s will still work ?

[JasonB]

So for a 1989 GS500 with a stock air-filter, a carbon slip-on what jets should I buy for improved performance ?

For this you shouldnt change the jetting.

Now if you got the K&N pod filter and the same thing then 140's would be about right maybe a bit lean since I am doing 140's with stock exhaust and plugs look perfect. And 150's with a Yosh or other full exhaust.

Just adding larger jets wont make more power, need to add intake or exhaust or other power adders.

[The Buddha]

He's right on all counts...125/40 is what aussie bikes had...and that should be right for your set up...Just bigger jets wont make power...you lose power real quick if you over shoot on jetting.
Cool.
Srinath.

[giraffe]

Hey thanks I really appreciate it !  

I actually just purchased an old stock VFR750 exhaust - the sound of the carbon is nice but my commutes are long and the noise gets tiring

Time for a bit of exhaust theory, I haven't received the exhaust, but once fitted and welded on .. I was wondering how the bike would respond to the new exhaust.

If all stock bike exhausts have to stay below a certain level of noise, an exhaust from a bigger bike would have to be more restrictive.

For example if both the Yamaha R6 and R1 and limited to 50db, then the R1 would have to have a more restrictive pipe than the R6 right, the engine is louder/bigger !

So if I fit a stock VFR750 exhaust to replace a GS500 exhaust the VFR pipe would actually allow the flow of LESS gas .. is that correct ?