Main Jet Question

[Guest]

Ok fellers,

I'm waiting on brake parts to arrive so I decided to take a float bowl off and see what jets were installed in my 82 GS850GL CV carbs.

Am I correct? Is this a main jet from a Dyno Jet stage 3 kit?



The stamp says 170 RD.

I am running K&N pods and a 4 into 1 Vance and Hines megaphone. If this is the case then I think this is the right setup correct?

I have wondered if the carbs were jetted correctly for the pods and pipe because of the amount of bluing on the pipes. But it could have been running lean from the old intake boots and "flat as a pancake" o-rings. Those have been replaced.

Thoughts?

[Steve]

Stock jets are Mikuni 115. Jetting for pods and a pipe should be about Mikuni 130 or so. Mikuni 130 is about a DynoJet 138.

If those are, indeed, DynoJet 170s, you are SERIOUSLY overjetted.

Are you sure those are main jets and not the pilot air jets that fit in the intake throat? Those can easily be 170s to be correct.

.

[Good Times]

Actually I'm not sure about anything with the jets. This is the big jet that is between the floats when you remove the float bowl. That's the main jet correct? The one that picks up the fuel from the float bowl.

[Steve]

Yes, that is the main jet, but I think the pilot air jet is also capable of screwing into the same threads.

Some bozo might have put a pilot air jet in there just to have bigger jets.

.

[Good Times]

Sooooo.....it ain't right.......

Looks like I'll be ordering up a DJ stage 3 kit.

[Steve]

Do you also have the rubber plug that goes over the pilot fuel jet?

If not, you had better get a set of those, too.

.

[Steel Toed Tank]

That is an EBC RD Precision brand Mikuni-Style Slot Head (SJ Prefix) Main Jet. Also 170 is the largest one they make.

[7981GS]

Looks like I'll be ordering up a DJ stage 3 kit.

Why not just order (4) 120 main jets from Z1 Enterprises for about $12.00 with shipping and save a bunch of money first and see how that works?
Oh yeah, and the (4) well plugs for another $10.00 from Z1 while you are ordering some parts anyway.

Eric

[Good Times]

Do you also have the rubber plug that goes over the pilot fuel jet?

If not, you had better get a set of those, too.

.

Yes, I have that. I just took it out to see what was in there.

That is an EBC RD Precision brand Mikuni-Style Slot Head (SJ Prefix) Main Jet. Also 170 is the largest one they make.

Just saw that after a quick search. It looks like a PO's motto was go big or go home. It was running a tad rich!

Dang it.

Shouldn't surprise me with other stuff I've found on the bike. I'm betting he just stuck that jet in there.

I'm also betting that when I get these carbs right that I won't recognize this bike when I ride it. I already don't recognize it when I look at it.

[Good Times]

Why not just order (4) 120 main jets from Z1 Enterprises for about $12.00 with shipping and save a bunch of money first and see how that works?
Oh yeah, and the (4) well plugs for another $10.00 from Z1 while you are ordering some parts anyway.

Eric

Wouldn't you know that I am waiting on parts from Z1 right now. LOL

[Steve]

Why not just order (4) 120 main jets from Z1 Enterprises for about $12.00 with shipping and save a bunch of money first and see how that works?

The 120s would work if he had a rather quiet (restrictive) header and a stock airbox. That is what my son has on his 850.

However, Good Times also has pods, which is why I was suggesting something in the 130 range.

Might end up with 127.5, 130, 132.5 or something else, but it should be close.

.

[Good Times]

The 120s would work if he had a rather quiet (restrictive) header and a stock airbox. That is what my son has on his 850.

However, Good Times also has pods, which is why I was suggesting something in the 130 range.

Might end up with 127.5, 130, 132.5 or something else, but it should be close.

.

Ok, so this brings up another option for me as well. Here goes the can of worms.......open!

I also have a stock air box that I could go with. I think if I had a stock exhaust I would do that, but with the pipes I lean toward putting the pods back on.

Of course no one on the board has any opinions about pods vs. stock box right?

[Badooka]

Where the rubber plugs missing or you take em out?

[Good Times]

Where the rubber plugs missing or you take em out?

Took it out. It just isn't in the picture.

[7981GS]

I had pod air filters and stock exhaust on my '80 850 and the cure was to just simply change the main jets from 115's to 117.5's on it.
As I ride at 4,000 feet and up elevation, that is why I suggested going to 120's.
Kentucky is a little lower than where I ride thus the 120 main jet suggestion.
Jet as necessary.

Eric