Hey,

Does anyone knows what is the stock pilot jet on the 34mm carb? I'm looking for the flow and the mikuni ref (there are various mikuni pilot jets: MKT, MKU and MKZ).

I installed a K&N lunchbox on my 2006 GS500 and I rejetted with:
*dinojet needle (from dinojet stage 1 kit http://www.dynojet.com/pdf/3156.pdf)
*140 main jet (I'm talking of dinojet jet, don't know if the flow is equivalent of mikuni)
*18 pilot jet (again, I'm talking of dinojet jet, don't know if the flow is equivalent of mikuni)

The bike is running PERFECT except for when I close the throttle because then the bike farts. So I figured out I need to enlarge my pilot jet but I can't find anywhere to buy 22 dinojet pilots jet where I live so I was thinking of buying mikuni 22 pilot jet (hoping the flow is equivalent to dinojet) but there are many references for mikuni pilots jet ( MKT, MKU and MKZ).

thanks

Quote from: gsf500RR on September 30, 2011, 07:50:31 AM
Hey,
bike farts.
thanks

I have the popping on deceleration issue, and from what I have read it can be explained:
http://www.allthingsmoto.com/forums/f-13/deceleration-popping-explained-10/

"This is exactly correct! If you think about the mechanics of what is going on upon decel, it makes perfect sense:
You start out with an engine that is turning high RPM with a carb that is open, flowing freely. Next, you close that slide. This has the effect of creating a tremendous vaccuum in the intake manifold (CHOKE!). This vaccuum does curious things:
1. It pulls air and fuel from wherever it can--including the idle and low speed jetting in the carb.
2. To counteract the vaccuum, air will take the path of least resistance--including sucking exhaust gases back into the combustion chamber during valve overlap (the brief period of time that the exhaust and intake valves are open at the same time.

So what does this mean? Well, now you have a disproportionate rich mixture heading for the cylinder AND what little oxygen is drawn in is further diluted by gases that are coming back into the chamber from the exhaust valve. The result is poor, incomplete combustion! Depending on the temperature of the exhaust pipe and gases, reignition is possible once this mixture is introduced into a more oxygen rich environment. This produces the "pop."

Why does a lean running engine have a tendency to excessively pop? The exhaust gas temperature of a lean engine is substantially higher than one that is running on the rich side ( an EGT probe will show this). Therefore, the high EGT serves to heat the pipe more and the gases themselves become a much better source of re-ignition. By richening things up, you are cooling down the exhaust temp and therefore reducing potential re-ignition sources.

Any 4 stroke engine--even those that are flawlessly tuned will pop on decel. It is harmless, but can be annoying--granted. However, I would never alter the jetting of an otherwise performing motorcycle to get rid of it. Go by the seat of your pants and the color of your spark plug rather than the popping as an indication of the jetting of your scoot!"

So basically as long as you aren't shooting 4 foot flames while you're engine braking from 4,000 rpm down, I wouldn't be too worried about it.

Anyone else have some thoughts?

^^ interesting read but I'm pretty sure it's quite bad for the engine and some people run a lunchbox without over farting on decel so it's possible to solve the issue.

When I'm not downshifting as a way to slow down my bike doesn't pop that much but when I'm going to 10k rev then hard downshift it make quiet a lot of farts and by the sound of it I feel like I'm killing my engine. I know some people like it this way but how long does their engine last? That's the question, if it didn't hurt the engine I wouldn't care about it (oh wait, it's actually awesome to have a farting bike  ).

All I need to do is to encrease the jet pilot. But I got dinojet 18 and I don't know if mikuni 22 will actually be 5 points bigger flow than dinojet 18.

Tomorow I will put picture of my plug, but I'm already certain they will be white

okay so I found pictures of the differents mikuni pilots jet. Wich one is the good?

You want Mikuni N224.103 idle jets for the 01+ three jet carbs.
I fitted 22.5 jets with K&N lunchbox and Yoshi TRS slip on. Screws 3 turns out. Runs really well, warms up and holds idle much quicker. Still pops and crackles on decel, I kinda like it

These are the ones I bought,
http://www.ebay.com.au/itm/150637850390

Quote from: mitch79 on October 01, 2011, 09:20:42 AM
You want Mikuni N224.103 idle jets for the 01+ three jet carbs.
I fitted 22.5 jets with K&N lunchbox and Yoshi TRS slip on. Screws 3 turns out. Runs really well, warms up and holds idle much quicker. Still pops and crackles on decel, I kinda like it

These are the ones I bought,
http://www.ebay.com.au/itm/150637850390

^^ Thanks, exactly what I was looking for (I also find out it was on the wikipedia but I didn't found it on first try  ). When you say it pop on decel does it pop hard and loud or just a little?

Here are pics of my plugs: http://gstwins.com/gsboard/index.php?topic=57890.0