Help! Carb jet issues

scootr9718 · February 19, 2005, 06:20:49 PM

OK, so, I pulled my carbs today to clean them and also see what the settings were on it.
I purchased the bike with a V&H pipe and stock air filter/box on it. The previous owner said it had been rejetted for this.
When I got it, I dropped in a UNI filter, leaving stock airbox.
Today, when I pulled the carbs to look, here is the set up...
air mixture screw 5 turns out.
37.5 pilots
122 Mains (could these be 122.5 and they just didn't have room to print that?)
1 washer under needles.

So, it looks like I should adjust these settings a bit. I originally pulled the carbs to clean and check float height cause I was getting crappy gas mileage...could the jets have to do with that? Should I go to 40 pilots and 125 mains? :dunno:
THANKS everone for feedback!

scratch · February 20, 2005, 09:40:43 AM

I don't have any experience with jetting for the V&Hines, but your carbs are basically stock, so going with the srinath standard of 125 mains and 40 pilots shouldn't hurt. Maybe then you can screw in the mix screws and hopefully that will help cure your crappy fuel economy (set them to 3 turns out).

The Buddha · February 20, 2005, 10:06:23 AM

Look at the needle ... if it has grooves its a DJ ... 122.5's say 122.5 in no uncertain terms ... 122 is what DJ gives you ... along with adjustable needles cut very thin ... Its what they call a richer stage 1 ... 118 is their regular stage 1 ...
Cool.
Srinath.

scootr9718 · February 20, 2005, 12:52:55 PM

OK, so the needle does have grooves in it, so I guess they used a dynojet kit...so should I mess with it, and change the jets? Does this mean I have to get a new needle? or can I stay with the needle I have, and just get the 40 and 125 jets?

The Buddha · February 21, 2005, 12:02:15 AM

OK Post the symptoms and problems you having ... if you dont have serious problems leave the thing alone ... so far no one here seems to find their way around a DJ kit and post about it ... there are plenty of people struggling with one ... some that drop it in and its great, and that's it ...
Cool.
Srinath.

Rema1000 · February 23, 2005, 10:56:50 AM

If the Dynojet needles are giving you fits, I'd be happy to swap those for a pair of stock needles. I'll also throw in new pilot and main jets, any size (I have a local distributor with full selection).

The reason I am interested is that I burn ethanol, and have gone waaay up on the jet sizes (57 pilot, 160 main jet) to compensate for the oxygenates in the alcohol. But there's only so much I can do to midrange by shimming the needle. I'd be interested in trying the Dynojet needles to see if they would help my midrange needs for a very rich fuel mixture.

(any guesses, Srinath?)

se7enty7 · February 23, 2005, 02:02:15 PM

Quote from: Rema1000If the Dynojet needles are giving you fits, I'd be happy to swap those for a pair of stock needles. I'll also throw in new pilot and main jets, any size (I have a local distributor with full selection).

The reason I am interested is that I burn ethanol, and have gone waaay up on the jet sizes (57 pilot, 160 main jet) to compensate for the oxygenates in the alcohol. But there's only so much I can do to midrange by shimming the needle. I'd be interested in trying the Dynojet needles to see if they would help my midrange needs for a very rich fuel mixture.

(any guesses, Srinath?)

I'll trade you DJ needles, their highest flowing 134 jets for stock needles and 127.5 jets

scootr9718 · February 23, 2005, 04:14:32 PM

actually, I got 125 Mains, and 40 pilots swapped in, and I'm going to put the carb back on the bike today, so I'll let you know how it runs....and if I want to part with the DJ needle...I'm sure I'll need some time to fiddle with the air/fuel mix too...

The Buddha · February 23, 2005, 04:44:09 PM

Quote from: se7enty7
Quote from: Rema1000If the Dynojet needles are giving you fits, I'd be happy to swap those for a pair of stock needles. I'll also throw in new pilot and main jets, any size (I have a local distributor with full selection).

The reason I am interested is that I burn ethanol, and have gone waaay up on the jet sizes (57 pilot, 160 main jet) to compensate for the oxygenates in the alcohol. But there's only so much I can do to midrange by shimming the needle. I'd be interested in trying the Dynojet needles to see if they would help my midrange needs for a very rich fuel mixture.

(any guesses, Srinath?)

I'll trade you DJ needles, their highest flowing 134 jets for stock needles and 127.5 jets

I dont mind helping out Rema here ... but we need to figure out the DJ sheiete ...
OK So Rema ... in Theory ... 175 mains will do what the DJ needle will do ... They dont have mains that big? ?? I guess you could hit 175 and still be lean and need 190 ... whatever ... up to you guys ...
Cool.
Srinath.

Rema1000 · February 24, 2005, 09:32:48 PM

Quote from: seshadri_srinathin Theory ... 175 mains will do what the DJ needle will do ... They dont have mains that big? ?? I guess you could hit 175 and still be lean and need 190 ...

Hmm, the way I thought I understood it, the jet needle partially blocks fuel flow through the needle jet. The higher-up the slides and the jet needle are, the thinner the needle is, and the less it blocks fuel flow. Once the needle is high enough, it is completely out of the needle jet, and has no effect at all on fuel flow (at WOT).

I had been thinking that by opening-up the pilot and mains, I had gotten my idle and WOT working fine. But I have been worried that I'm running lean in the mid-range, and might possibly do some damage to the engine over time. Shimming the needle helps, but it would seem like a narrower needle would be the "right thing to do" to get a bit richer when off-the-line.

But from your description, it sounds like the needle shape still has an effect, even at WOT? That must mean that it's never really out of the needle jet.

The Buddha · February 25, 2005, 07:51:54 AM

OK Needle never leaves the emulsion tube ... so its taper always is affecting ... Making it thinner is going to richen up the mix no matter what ... OK so you want its WOT to not change, but 1/2 to 3/4 throttle to improve ... You would prolly be best served with a needle that has no taper in the bottom 1/2-3/4 inch ... DJ needle is steep and sudden taper in the last 1/4 ... opposite of what you need ... Can you start with a stock needle and turn the bottom 3/4 inch to the same thickness as the last 1/8th or somehting ... DJ is far to thin for too short a length to make anything out of ...
Cool.
Srinath.

Rema1000 · February 25, 2005, 01:06:37 PM

That makes sense; thanks, Srinath. I've never seen a DJ needle, and I guess I was making assumptions about its shape.

Sorry, Scootr and Seventy7, now that I have a better idea what the DJ needles look like, I'm going to have to retract my offer (sorry if that's rude).

scootr9718 · February 25, 2005, 04:20:07 PM

That's ok, I don't know what a stock needle looks like, as this bike had the DJ on it when I got it. I swapped the jets in, and I fiddled with the mix screws a bit...at first i smelled gas a lot, so I'm not sure if more adjusting is needed, maybe I'm running a bit rich?

The Buddha · February 25, 2005, 07:56:57 PM

You smelling gas ... its leaking from somewhere ... however rich ... white smoke, misfiring with wet soppy noise, and black and fouled plugs ... gas smell more than likely is high floats making liquid gas out the airbox ... or some other leak ...
Cool.
Srinath.

The Buddha · February 25, 2005, 07:59:52 PM

Quote from: Rema1000That makes sense; thanks, Srinath. I've never seen a DJ needle, and I guess I was making assumptions about its shape.

Sorry, Scootr and Seventy7, now that I have a better idea what the DJ needles look like, I'm going to have to retract my offer (sorry if that's rude).

You are almost certailny going to have to make needles ... Measure the last 1/8 of your needle and for the next 1/2 inch make that taper disappear or close ... That way your mid range will richen up and the WOT will stay the same ... any lifting of the needle will cause the taper effect to snoball into a richer WOT ... swapping for DJ ... OK DJ is set too lean at mid and rich WOT ...
Cool.
Srinath.

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Help! Carb jet issues